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Lipoproteins from the Hemolymph and Ovaries of Marine Invertebrates
Abstract
Lipids are involved in a number of essential processes in the growth and reproduction of marine invertebrates. Membrane lipids, primarily phospholipids and sterols, combine with membrane proteins to form insoluble complexes that are important in membrane structure. Many marine invertebrates have oil droplets within cells of hepatic-type tissues. These droplets are primarily triacylglycerols or wax esters and serve as energy stores. Finally, lipids occur in water-soluble lipoproteins where phospholipids, triacylglycerols, and sterols are combined with various apoproteins. Lipids are transported between various tissues via hemolymph lipoproteins. Female-specific lipoproteins occur in the hemolymph and eggs of adult females of many marine invertebrates. These egg lipoproteins provide protein and lipid for the development of larvae after they hatch from the egg.
... buoyancy 12,13 , tissue growth, immunity, and wound healing 2,3,14 . In addition, there is a direct link between reproduction and lipid metabolism in animals since lipids are used as energy storage 15 in the eggs during gamete formation and embryogenesis of many marine organisms, including zooplankton, crustacea, cnidaria and fish [16][17][18][19][20] . Nutrient acquisition and transport, lipid metabolism, and yolk accumulation (which dictates the stage of vitellogenesis) are crucial processes during gametogenesis/embryogenesis because they determine the production of a successful gamete and propagule 20-24 , and in parallel they can affect the survival of the adult during reproduction. ...
... www.nature.com/scientificreports/ in order to withstand the high energetic demands [25][26][27] . Due to its importance, the relationship of lipid metabolism with seasonal environmental changes and the reproductive period has been studied in several marine organisms across their development, addressing questions such as: which types of lipids are preferred for yolk formation; what is the source of these lipids (e.g. to understand the food web dynamics); and what is the timing of lipid synthesis, lipid accumulation and lipid consumption 2,11,16,18,19,[28][29][30][31][32][33] . Sponges (phylum Porifera), especially within the class Demospongiae, produce an exceptional diversity of lipids [34][35][36][37][38][39][40] . ...
... TGs have a hydrophobic nature and they are transported extracellularly or intracellularly in animals in the form of lipoproteins 137 . Even though there are no studies discussing the presence and role of lipoproteins in sponges, it is known that lipoproteins have appeared early in evolution 137 and have been detected in ovaries of marine invertebrates, playing a role in lipid transport 16,138 . In our transcriptomic data, GO enriched categories ("very-low-density lipoprotein particle assembly" and "lipoprotein particle binding") and overexpressed genes related to lipoprotein formation (low-density lipoprotein receptor-related protein, lrp; low density lipoprotein receptor adapter protein 1, ldlrap1; low-density lipoprotein receptor, ldlr; and apolipoprotein L3, apol3) in females, compared to NR (see Results section) (Fig. 8A, C; Supplementary Table S5; Supplementary Table S6; Supplementary Table S7), strengthen the hypothesis that lipid transport, including TG transport, in sponges occurs also with the help of lipoproteins as in the sea anemone Nematostella vectensis Stephenson, 1935 138 . ...
Sponges contain an astounding diversity of lipids that serve in several biological functions, including yolk formation in their oocytes and embryos. The study of lipid metabolism during reproduction can provide information on food-web dynamics and energetic needs of the populations in their habitats, however, there are no studies focusing on the lipid metabolism of sponges during their seasonal reproduction. In this study, we used histology, lipidome profiling (UHPLC-MS), and transcriptomic analysis (RNA-seq) on the deep-sea sponge Phakellia ventilabrum (Demospongiae, Bubarida), a key species of North-Atlantic sponge grounds, with the goal to (i) assess the reproductive strategy and seasonality of this species, (ii) examine the relative changes in the lipidome signal and the gene expression patterns of the enzymes participating in lipid metabolism during oogenesis. Phakellia ventilabrum is an oviparous and most certainly gonochoristic species, reproducing in May and September in the different studied areas. Half of the specimens were reproducing, generating two to five oocytes per mm ² . Oocytes accumulated lipid droplets and as oogenesis progressed, the signal of most of the unsaturated and monounsaturated triacylglycerides increased, as well as of a few other phospholipids. In parallel, we detected upregulation of genes in female tissues related to triacylglyceride biosynthesis and others related to fatty acid beta-oxidation. Triacylglycerides are likely the main type of lipid forming the yolk in P. ventilabrum since this lipid category has the most marked changes. In parallel, other lipid categories were engaged in fatty acid beta-oxidation to cover the energy requirements of female individuals during oogenesis. In this study, the reproductive activity of the sponge P. ventilabrum was studied for the first time uncovering their seasonality and revealing 759 lipids, including 155 triacylglycerides. Our study has ecological and evolutionary implications providing essential information for understanding the molecular basis of reproduction and the origins and formation of lipid yolk in early-branching metazoans.
... Lipids are also used as energy storage (15) in the eggs during gamete formation and embryogenesis of many marine organisms, including zooplankton, crustacea, cnidaria and sh (16)(17)(18)(19). There is therefore a direct link between reproduction and lipid metabolism in animals (20). ...
... For this reason, many species synchronize their gametogenesis with periods of high food availability in the environment in order to withstand the high energetic demands (25)(26)(27). Due to its importance, the relationship of lipid metabolism with seasonal environmental changes and the reproductive period has been studied in several marine organisms across their development, addressing questions such as: which types of lipids are preferred for the yolk formation; what is the source of these lipids (e.g. to understand the food web dynamics); and what is the timing of lipid synthesis, lipid accumulation and lipid consumption (2,11,16,18,19,(28)(29)(30)(31)(32)(33). ...
... TGs have a hydrophobic nature and they are transported extracellularly or intracellularly in animals in the form of lipoproteins (120). Even though there are no studies discussing the presence and role of lipoproteins in sponges, it is known that lipoproteins have appeared early in evolution (120) and have been detected in ovaries of marine invertebrates, playing a role in lipid transport (16). So, we expect that lipid transport occurs in a similar way in sponges, including the TG transport. ...
Background Sponges contain an astounding diversity of lipids which serve in several biological functions, including yolk formation in their oocytes and the embryos. On animal reproduction, lipids constitute one of the main energy storage forms for the adult and the offspring. The study of lipid metabolism during reproduction can provide information on food-web dynamics and energetic needs of the populations in their habitats, however, there are no studies focusing on the lipid metabolism of sponges during seasonal reproduction. The deep-sea sponge Phakellia ventilabrum (Demospongiae, Bubarida) is a key species of North-Atlantic sponge grounds, but its reproductive biology is not known. In this study, we used histological sections, lipidome profiling (UHPLC-MS), and transcriptomic analysis (RNA-seq) with goal to i. assess the reproductive strategy and seasonality of this species, ii. examine the relative changes in the lipidome signal, and the gene expression patterns (RNA-seq) of enzymes participating in lipid metabolism in female specimens during gametogenesis.
Results P. ventilabrum is an oviparous and most certainly gonochoristic species, reproducing in May and September in the different studied areas. Half of specimens were reproducing, generating two to five oocytes per mm². Oocytes accumulated both protein and lipid droplets. As oogenesis progressed, the signal of most of the unsaturated and monounsaturated triacylglycerides increased, as well as of few other phospholipids. Most of the other lipids and especially those with > 3 unsaturations showed a decrease in signal during the oocyte maturation. In parallel, we detected upregulated genes in female tissues related to triacylglyceride biosynthesis and others related to fatty acid beta-oxidation.
Conclusions Triacylglycerides are probably the main type of lipid forming the yolk since this lipid category has the most marked changes, while some other phospholipids may also have a role in oogenesis. In parallel, other lipid categories were oxidized, leading to fatty acid beta-oxidation to cover the energy requirements of female individuals during oogenesis. Variations in the signal of most lipids between the different locations and months suggest that sponges, apart from their own mechanisms of lipid biosynthesis, exploit the food availability in their surroundings to cover the energetic demands in their physiological processes.
... Plasma Lps transport lipids from different tissues, including polyunsaturated fatty acids and cholesterol that are provided mainly by the diet (Teshima & Kanazawa 1971, Van den Oord 1964, Zandee 1964. Similar to vertebrate Lps, crustacean Lps are classified according to their density as high, low and very low density Lps (Kanost et al. 1990, Stratakis et al. 1992, although to our knowledge, only HDL and VHDL have been detected (Hall et al. 1995, Komatsu & Ando 1992, Komatsu et al. 1993, Lee 1990, Spaziani et al. 1995, Yepiz-Plascencia et al. 1995. The HDLs appear to be more abundant than VHDLs and contain more lipid. ...
... Two different types of HDLs have been reported in crustaceans. One of them seems to be non sex-specific, while the other is found in ovigerous females and related to vitellogenesis (Lee 1990, Lubzens et al. 1997. The non sex-specific HDL appears to be simpler in apolipoprotein composi-tion than the female-specific HDL, since it contains only one high molecular mass subunit (100-112 kDa), whereas vitellogenin has several medium size apolipoproteins (Lubzens et al. 1997, Stratakis et al. 1992. ...
... The non sex-specific HDL appears to be simpler in apolipoprotein composi-tion than the female-specific HDL, since it contains only one high molecular mass subunit (100-112 kDa), whereas vitellogenin has several medium size apolipoproteins (Lubzens et al. 1997, Stratakis et al. 1992. The lipid moiety of crustacean Lps is composed mainly by phospholipids (Lee 1990, Lubzens et al. 1997, Stratakis et al. 1992, in contrast to insect Lps that contain mainly diacylglycerol (Kanost et al. 1990); therefore, crustacean Lps differ from their insect counterparts in their protein and lipid constituents. ...
In the hemolymph of marine shrimp, a high density lipoprotein (HDL) and a ß-glucan binding protein (BGBP) have been found. These proteins are involved in the transport of lipids and in the recognition of foreign matter, respectively. Similarities between the color and molecular mass of these proteins were initially detected. To do a detailed comparison, HDL and BGBP were purified, and characterised from three shrimp species, white shrimp Penaeus vannamei, brown shrimp P. californiensis and blue shrimp P. stylirostris. HDL was purified by two sequential density gradient ultracentrifugation steps while BGBP was purified by carbohy-drate (laminarin) affinity chromatography. Both proteins were monomeric with approximately the same molecu-lar mass by SDS-PAGE (~100-112 kDa). Both were recognized by ConA and WGA, indicating that they are glycoproteins. Since shrimp HDLs contain lipids, they have a lower density than the majority of shrimp plasma proteins. This allowed their purification by density gradient ultracentrifugation. Purified HDL from P. vannamei had densities of 1.12-1.14 g/ml, while those from P. californiensis and P. stylirostris had average densities of 1.139 and 1.137 g/ml, respectively. These proteins also had similar amino acid composition and high sequence identity in the N-terminus. Polyclonal antibodies were prepared against P. vannamei HDL (anti-HDL) and P. californiensis BGBP (anti-BGBP). Both antibodies recognized the six proteins: HDL and BGBP from P. vannamei, HDL and BGBP from P. californiensis and HDL and BGBP from P. stylirostris. Therefore, BGBP and HDL appear to be the same protein. This suggests a very close relationship amongst molecules of the immune system in different shrimp species.
... density female-specific lipoprotein (15,19), which is involved in the transport of lipids to the ovary for reproduc-Lipids are very important macromolecules for all living ortion. However, there are few studies on the lipid mobilizaganisms, including crustacean since they are the major tion processes or changes during development and the source of energy and provide essential components for memmolecules involved in these processes. ...
... Significant homology was found with crayfish Paci-Considering that protein and lipids are the highest organic fastacus leniusculus. HDL (10), the only crustacean lipoprocomponents in crustacean plasma (19) and taking only tein sequence reported to our knowledge. Ten of 15 amino these two into consideration, these values correspond to acid residues are the same or 67% identity. ...
... The method, stained with phospray, ninhydrin and Dragendorff 's rewith adequate modifications, has been used for isolation of agent. From more to less abundant the following comlipoprotein from organisms as diverse as humans (6,38), ponents were identified: phosphatidylcholine (PC), phosfishes (13), insects (24), and crustacea (17,19,40). The prephatidylethanolamine (PE), phosphatidylserine (PS), viously reported method for isolation of white shrimp HDL sphingomyelin (SP), and lisophosphatidylcholine (LPC). ...
Studies about lipids are taking importance in shrimp, due to their physiological role in nutrition, development and reproduction. These molecules are mobilized through hemolymph by lipoproteins. A 98 kDa high density lipoprotein (HDL) has been detected in shrimp plasma and it is non–sex-associated, since it is present in both, male and female juvenile shrimp. The HDL was purified by density gradient ultracentrifugation from the hemolymph of juvenile white shrimp Penaeus vannamei males and females, separately; and the protein and lipid moieties studied. The amino acid composition and the N-terminal sequence for 15 residues of the 98 kDa apolipoprotein were determined. In addition, the plasma lipid components from male and female were detected by TLC, identifying phospholipids, sterols, and acylglycerols. The lipid concentration of plasma and purified HDL were determined by enzymatic assays, quantifying phosphatidyl choline, acylglycerols, free fatty acids and sterols. Similar concentrations of the lipid classes were found in male and female HDL confirming its sex independence. Purified HDL contains approximately 50% lipids, where the major components are phospholipids followed by acylglycerols, sterols, and free fatty acids. Considering that the HDL plasma concentration is approximately 2% of total protein, HDL could be the major lipid-transporting molecule in shrimp.
... Thus, these proteins are fulfilling a dual role in the animal and the term high density lipoprotein/β-glucan binding protein (HDL-BGBP) was coined to reflect this dual role and is now used to describe these special proteins. In the hemolymph of the crayfish Astacus leptodactylus, HDL-BGBP is a rather abundant protein present in concentration ranges between 1 and 6 mg/ml (Stieb et al. 2014), whereas in marine crustaceans HDL-BGBP seems to be present in even broader concentration ranges, ranging between 0.3 and 6.8 mg/mL (Lee andPuppione 1978, 1988;Spaziani and Wang 1991). ...
... VTGs have native molecular masses between 325 and 700 KDa (see Wilder et al. 2010, Table 2; and Lee 1991, Table 5, for an overview) with lipid contents between 19 and 50% (see Table 1). In addition to neutral-and phospholipids, crustacean VTGs contain various amounts of carotenoids, mainly astaxanthin, canthaxanthine and β-carotene (for an overview, see Lee 1991). Carotenoids may protect from excess radiation (Sagi et al. 1995 and cited references). ...
Lipoproteins mediate the transport of apolar lipids in the hydrophilic environment of physiological fluids such as the vertebrate blood and the arthropod hemolymph. In this overview, we will focus on the hemolymph lipoproteins in Crustacea that have received most attention during the last years: the high density lipoprotein/β-glucan binding proteins (HDL-BGBPs), the vitellogenins (VGs), the clotting proteins (CPs) and the more recently discovered large discoidal lipoproteins (dLPs). VGs are female specific lipoproteins which supply both proteins and lipids as storage material for the oocyte for later use by the developing embryo. Unusual within the invertebrates, the crustacean yolk proteins—formerly designated VGs—are more related to the ApoB type lipoproteins of vertebrates and are now termed apolipocrustaceins. The CPs on the other hand, which are present in both sexes, are related to the (sex specific) VGs of insects and vertebrates. CPs serve in hemostasis and wound closure but also as storage proteins in the oocyte. The HDL-BGBPs are the main lipid transporters, but are also involved in immune defense. Most crustacean lipoproteins belong to the family of the large lipid transfer proteins (LLTPs) such as the intracellular microsomal triglyceride transfer protein, the VGs, CPs and the dLPs. In contrast, the HDL-BGBPs do not belong to the LLTPs and their relationship with other lipoproteins is unknown. However, they originate from a common precursor with the dLPs, whose functions are as yet unknown. The majority of lipoprotein studies have focused on decapod crustaceans, especially shrimps, due to their economic importance. However, we will present evidence that the HDL-BGBPs are restricted to the decapod crustaceans which raises the question as to the main lipid transporting proteins of the other crustacean groups. The diversity of crustaceans lipoproteins thus appears to be more complex than reflected by the present state of knowledge.
... In addition, it was reported that female crayfish, Procambarus clarkii, given 5-HT exhibited a significant increase in ovarian index and oocyte size (Sarojini et al., 1995). Similar results are reported from several crustacean species, with a substantial increase of vitellogenin content in the hemolymph during vitellogenesis (Lee, 1991). Vitellogenesis acts as a biomarker in female reproductive activities, which indicate that the vitellin accumulation gradually increased in oocytes during ovarian development (Quackenbush, 1989). ...
... Several hormonal factors such as methyl farnesoate, a structural homologue of insect juvenile hormone, ecdysteroids as well as vertebrate steroids like 17β-estradiol (E2) and YG EX VO kidney, hepatopancreas, hemolymph, ovary and testis of the crustaceans (Yano, 1985;Subramoniam, 1999). This type of work also helps to understand the mechanism of hormonal role in gonadal maturation of the commercially important the case of crustaceans there is evidence that vitellogenin is synthesized in several tissues including the hepatopancreas and the ovary itself (Shafir et al., 1992;Khayat et al., 1994;Lee and Chang, 1999).In these organisms, secondary vitellogenesis is accompanied by the accumulation of yolk, composed of lipids, carbohydrates, and proteins (Adiyodi and Subramoniam, 1983) circulating in the hemolymph as VTG, a high-density lipoprotein (HDL) (Lee andPuppione, 1988,Abdu et al., 2000.In our study the effect of the sex steroids 17-βestradiol and progesterone on giant freshwater prawn reproduction, is used as VTG marker. Female Macrobrachium rosenbergii which are injected with Progesterone and estradiol for ovarian development in comparison of control shows the appearance of many primary granule stage (PGS) oocytes contained in extensive accumulation of yolk granules dispersed throughout the cytoplasm. ...
Due to the growing requirement of high protein food from aquatic sources and to find a substitute for fisheries, prawn culture is the major restricted access in crustacean aquaculture industry. It is imperative to understand the physiological mechanisms involved in seed production of the candidate species. This review was carried out on studies of endocrine regulation of reproduction in giant fresh prawn Macro brachium rosenbergii. This type of work seems to be a practical substitute to eyestalk ablation to induce spawning. Since it is a commercially important crustacean, crustacean aquaculture industry and these hormonal manipulation like neurotransmitter and vertebrate type sex hormone indicted the possibility of introducing a new strategies for ovarian maturation in aquaculture.
... With permission from Blades-Eckelbarger (1991) Various polar euphausiids appear to utilize phosphatidylcholine as a storage lipid (Hagen 1988, Hagen et al. 1996, Mayzaud 1997. Phosphatidylcholine is the major lipid in high-density lipoproteins found in arthropod hemolymph (Lee & Puppione 1988, Lee 1991, Walker et al. 2003. These lipoproteins play an important role in transporting lipids from different tissues, e.g. ...
... Lipovitellins are utilized for energy and materials by the newly hatched larvae. Phosphatidylcholine is generally the major lipid component of lipovitellin with lesser amounts of cholesterol and triacylglycerols (Lee 1991). In Artemia salina, and presumably in other crustacean zooplankton, the lipovitellin is associated with egg-yolk granules (deChaffoy & Kondo 1980). ...
Zooplankton storage lipids play an important role during reproduction, food scarcity, ontogeny and diapause, as shown by studies in various oceanic regions. While triacylglycerols, the primary storage lipid of terrestrial animals, are found in almost all zooplankton species, wax esters are the dominant storage lipid in many deep-living and polar zooplankton taxa. Phospholipids and diacylglycerol ethers are the unique storage lipids used by polar euphausiids and pteropods, respectively. In zooplankton with large stores of wax esters, triacylglycerols are more rapidly turned over and used for short-term energy needs, while wax esters serve as long-term energy deposits. Zooplankton groups found in polar, westerlies, upwelling and coastal biomes are characterized by accumulation of large lipid stores. In contrast, zooplankton from the trades/tropical biomes is mainly composed of omnivorous species with only small lipid reserves. Diapausing copepods, which enter deep water after feeding on phytoplankton during spring/summer blooms or at the end of upwelling periods, are characterized by large oil sacs filled with wax esters. The thermal expansion and compressibility of wax esters may allow diapausing copepods and other deep-water zooplankton to be neutrally buoyant in cold deep waters, and they can thus avoid spending energy to remain at these depths. Lipid droplets are often noted in zooplankton ovaries, and a portion of these droplets can be transferred to developing oocytes. In addition to lipid droplets, zooplankton eggs have yolks with lipovitellin, a lipoprotein with approximately equal amounts of protein and lipid. The lipovitellin lipid is predominantly phosphatidylcholine, so during reproduction females must convert a portion of their storage lipid into this phospholipid. Developing embryos use their lipovitellin and lipid droplets for energy and materials until feeding begins. The various functions storage lipids serve during the different life history stages of zooplankton are very complex and still not fully understood and hence offer a multitude of fascinating research perspectives.
... In contrast to increase of MUFA 18:1(n − 7) and 18:1(n −9), the content of 18:0 decreased from D0 to D14 during larval development. 16 The proportion of saturated fatty acids in PC tended to decrease during larval development, whereas MUFA increased from 11 to 20 mol% (Table 3). ...
... During the endotrophic phase, a part of the PLSM, and also PC, could have been associated with yolk lipids of the eggs. In fact, lipoproteins (very high density lipoprotein) have been detected in the eggs of a number of molluscan species [16]. The lipoproteins are mainly constituted of a peptide [6,17] and lipid. ...
The major phospholipid classes in the larvae of the scallop Pecten maximus were phosphatidylcholine (PC) and plasmalogens (PLSM) (35.5 and 32.1 mol%, respectively). The minor classes were glycosyldiacylglycerol-like (GLY), phosphatidylinositol (PI), phosphatidylserine (PS) and non-plasmalogen phosphatidylethanolamine (PE) at 6.7, 9.1, 8.5 and 8.1 mol%, respectively. Abundance of phospholipid classes and their content of saturated, monounsaturated and polyunsaturated fatty acids remained relatively conserved during the course of larval development. During larval development there was a decrease in the amount of 20-carbon polyunsaturated fatty acids (PUFA) in the polar lipids, while the amount of 22-carbon PUFA remained constant. These changes, which occurred mainly during the lecithotrophic phase, imparted a specificity in PUFA composition to the different classes of polar lipids. During this phase, 20:5(n−3) replaced 20:4(n−6) in PI but decreased sharply in PLSM and, to a lesser extent, in PC. After the initial phase of composition changes, the fatty acid composition of the polar lipid classes became stable, with specific associations of some of the PUFA with certain polar lipid classes: 22:6(n−3) with GLY, 20:5(n−3) with PE, 20:4(n−6) with PI. The 22:6(n−3)/20:5(n−3) ratio in PLSM during exotrophy was always twice as high as in the PC fraction.
... Tsushima reported extracting carotenoids from the viscera, muscles, and gonads of chiton [31]. However, mollusks are unable to synthesize carotenoids and obtain them from food, transporting them to tissues with the involvement of key proteins [32], such as lipoproteins [33,34]apolipoproteins [35]and specific receptors [36]. Lipoproteins appear in the protein spectrum analysis of spicules and shell plates (Fig. 3). ...
... In most oviparous animals, high molecular weight serum yolk precursor proteins called vitellogenins serve as the principal source of yolk proteins. Vitellogenins are large female-specific phosphoglycolipoproteins that are incorporated into the oocytes where they are modified and assembled into proteins called vitellins or lipovitellins (Wallace et al. 1967;Byrne et al. 1989;Lee 1991;Sappington et al. 2002;Brooks and Wessel 2003a;Tufail et al. 2005;Biscotti et al. 2018). In most animals, yolk precursors are synthesized in a tissue-specific manner, but there is no universal site for precursor synthesis (Giorgi et al. 2005). ...
Oogenesis is a fundamental biological process observed in most animals. Animals employ many different mechanisms to make their eggs and oogenesis cannot be completed without the support of other intraovarian and/or extraovarian cells and tissues. Invertebrates account for 99% of all animal life on earth and their complex life histories are a reflection of the structural heterogeneity of their ovaries and the diversity of their vitellogenic mechanisms. The process of oogenesis in different invertebrates differs because it is constrained by limits imposed by their respective body design, the architecture of their ovaries and their collective phylogenetic history. Oogenesis in the majority of invertebrates has yet to be investigated and current knowledge is limited to relatively superficial descriptions of a fraction of 1% of described species in each of the major animal phyla. It has been over 30 years since the last published review of invertebrate oogenesis and during the intervening years considerable progress has been made in our understanding of the ultrastructural, biochemical and molecular aspects of the process. This review aims to identify some unifying themes by collating and synthesizing the widely dispersed literature on invertebrate oogenesis covering 30 metazoan phyla for which basic information is available.
... This might indicate that miR-8 and miR-8* co-regulate FRU during female sexual differentiation and gonadal development of S. paramamosain. LRP2 is multifunctional, and is involved in both male and female gonadal development, although in many marine invertebrates, there are female-specific lipoproteins in haemolymph to aid in the development of female reproduction (Lee 1991). The high expression of this gene during immature stages of testis and ovary, and the significantly higher expression in mature ovary compared to mature testis might indicate its i m p o r t a n c e i n t h e g o n a d a l d e v e l o p m e n t o f S. paramamosain. ...
Although the sexual dimorphism in terms of gonadal development and gametogenesis of mud crab has been described, the internal regulating mechanism and sex differentiation process remain unclear. A comparative gonadal miRNA transcriptomic study was conducted to identify miRNAs that are differentially expressed between testes and ovaries, and potentially uncover miRNAs that might be involved in sex differentiation and gonadal maturation mechanisms of mud crabs (Scylla paramamosain). A total of 10 known miRNAs and 130 novel miRNAs were identified, among which 54 were differentially expressed. Target gene prediction revealed a significant enrichment in 30 KEGG pathways, including some reproduction-related pathways, e.g. phosphatidylinositol signalling system and inositol phosphate metabolism pathways. Further analysis on six differentially expressed known miRNAs, six differentially expressed novel miRNAs and their reproduction-related putative target genes shows that both miRNAs and putative target genes showed stage-specific expression during gonadal maturation, suggesting their potential regulatory roles in sex differentiation and reproductive development. This study reveals the sex-biased miRNA profile and establishes a solid foundation for understanding the sex differentiation and gonadal maturation mechanisms of S. paramamosain.
... They are also key components of cell membranes [1], and are involved in numerous cellular and physiological processes crucial to the reproduction, growth, and general survival of organisms [2,3]. For example, lipids are deposited during oogenesis in fish and zooplankton [1,2], and several other marine taxa [1,2], and they can be transferred as lipoprotein from mother to oocytes to provide energy to embryos [4]. PLOS The Canadian province of Newfoundland and Labrador is located in a cold-temperate region of the Northwest Atlantic, where species with subarctic/Arctic affinities are common. ...
Lipids are key compounds in marine ecosystems being involved in organism growth, reproduction , and survival. Despite their biological significance and ease of measurement, the use of lipids in deep-sea studies is limited, as is our understanding of energy and nutrient flows in the deep ocean. Here, a comprehensive analysis of total lipid content, and lipid class and fatty acid composition, was used to explore functional diversity and nutritional content within a deep-sea faunal assemblage comprising 139 species from 8 phyla, including the Chordata, Arthropoda, and Cnidaria. A wide range of total lipid content and lipid class composition suggested a diversified set of energy allocation strategies across taxa. Overall, phospholipid was the dominant lipid class. While triacylglycerol was present in most taxa as the main form of energy storage, a few crustaceans, fish, jellyfishes, and corals had higher levels of wax esters/steryl esters instead. Type and amount of energy reserves may reflect dietary sources and environmental conditions for certain deep-sea taxa. Conversely, the composition of fatty acids was less diverse than that of lipid class composition, and large proportions of unsaturated fatty acids were detected, consistent with the growing literature on cold-water species. In addition, levels of unsaturation increased with depth, likely suggesting an adaptive strategy to maintain normal membrane structure and function in species found in deeper waters. Although proportions of n-3 fatty acids were high across all phyla, representatives of the Chordata and Arthropoda were the main reservoirs of these essential nutrients, thus suggesting health benefits to their consumers.
... Further, Byrne et al. (2008b) noted that nutrient reserves acquired by T. gratilla larvae during the FFP were not utilized for growth, but instead were allocated for storage. Further research would be required to determine possible drivers of protein increase during early larval development in A. mollis, which could be related to an increase in the secretion of digestive enzymes, or the synthesis of high-energy protein storage products such as lipoproteins (Lee 1991;Lee et al. 2006). ...
Echinoderms are widely used to investigate the relationship between egg size, energy content and larval developmental strategies in marine invertebrates; although there have been few studies on ophiuroids and holothuroids. In this paper, we provide the first detailed biochemical information on egg composition and utilization in the planktotrophic holothuroid, Australostichopus mollis. The egg ultrastructure, protein content (85.1 ng egg−1) and lipid:protein ratio of 0.42 were consistent with those of other planktotrophic echinoderms of similar egg size. However, the lipid content (35.6 ng egg−1) was outside the 95% prediction band for the relationship between egg size and lipid content for echinoderms. Triacylglycerol (TAG) was the main energetic lipid present in the egg, with ca 50% of the TAG being utilized to construct the feeding auricularia; the remaining TAG was estimated to be consumed over 114.8 h (4.8 days) of development. Feeding a microalgal diet during early larval development did not affect the rate of TAG utilization, but increased protein content in the 90-h auricularia. Biochemical information from A. mollis eggs/larvae suggests that TAG might be the ancestral maternally derived energetic lipid in the Echinodermata, but also that there may be different patterns of lipid utilization between different classes.
... Crustacean vitellin is a high molecular weight lipoglyco-carotenoprotein (Kerr, 1969). It is the major yolk protein of mature crustacean eggs and it is vital to the nutritional needs of the developing embryo (Lee, 1991). To assess potential adverse effects of xenobiotics on crustacean reproduction, it is imperative to measure accurately vitellogenin and vitellin in crustacean models (Tsukimura et al., 2000;Tuberty et al., 2002). ...
... Crustacean vitellin is a high molecular weight lipoglyco-carotenoprotein (Kerr, 1969). It is the major yolk protein of mature crustacean eggs and it is vital to the nutritional needs of the developing embryo (Lee, 1991). To assess potential adverse effects of xenobiotics on crustacean reproduction, it is imperative to measure accurately vitellogenin and vitellin in crustacean models (Tsukimura et al., 2000;Tuberty et al., 2002). ...
... high-density lipoproteins (Lee and Puppione, 1988). They originate from ingested food either directly or after storage in the hepatopancreas and must be transported via the hemolymph as lipoproteins (Allen, 1972 in M. nipponense (Vg range 1-9 mg/ml) (Okumura et al., 1993) and H. americanus (Vg range 0-12 mg/ml) (Byard and David, 1984 Similar results are reported from several crustacean species, with a substantial increase of vitellogenin content in the hemolymph during vitellogenesis (Lee, 1991;Okumura et al., 1993;Quackenbush, 1989;Vafopoulou and Steel, 1995). Although the site of vitellogenin synthesis is still controversial, some evidence indicates that the hepatopancreas is one of the possible sites (Castille and Lawrence, 1989;Paulus and Laufer, 1987). ...
... Insect lipids are mostly carried by the lipophorin lipoprotein in the form of phospholipids and diacylglycerol as energetic lipid (Chino, 1985;Blacklock and Ryan, 1994;Soulages and Wells, 1994;Gonzalez et al. 1995;Arrese et al. 2001). In crustaceans, high-density lipoproteins (HDL) transport lipids mostly in the form of phospholipids (Lee and Puppione, 1978;Chang and O´Connor, 1983;Lee, 1991;García et al. 2002a;2002b). Surprisingly, little information is available regarding the characterization of hemolymph lipoproteins for arachnids, where only four species have been studied (see review by Cunningham et al. 2007;. ...
VHDL fraction contains hemocyanin as its major apoprotein and transports most of the circulating lipids in the spider Polybetes pythagoricus (Sparassidae). This work shows that subfraction II (the major VHDL component) is composed of a single protein of 420 kDa under native conditions and three subunits, 67, 105 and 121 kDa under denaturing conditions. Circular dichroism indicated that this subfraction contains 20% α-helix, 29% β-sheet, 22.7% turns and 29.7% unordered structures. Comparison of trypsin susceptibility showed that the 105 and 121 kDa subunits were more susceptible indicating that these proteins would be more exposed to the aqueous medium. Peptide mass fingerprinting of the 67 and 105 kDa subunits indicated the 67 kDa subunit is similar to subunit 3 of the spider Cupiennius salei hemocyanin (21% sequence similarity), whereas the 105 kDa subunit is similar to a protein from the mosquito Anopheles gambiae (20% sequence similarity). The N-terminal amino acid sequence from subunit of 121 kDa was also determined. In relation to fatty acids, 16:0, 18:0, 18:1 and 18:2 were found to be the major components. These data provide a better understanding of VHDL subfraction II structure, which is responsible for most lipid transport in the spider P. pythagoricus. © 2015, Centro Regional de Invest. Cientif. y Tecn. All rights reserved.
... This could be accounted for by selective utilization of yolk components, already observed in fish and invertebrate embryos, and larvae (Kamler, 2008; Martínez et al., 2008). For L. reynaudii, no data on the biochemical profiles of the yolk are available, but cephalopod yolk is composed mostly of phospholipoproteins (Lee, 1991 ). Protein is catabolized for energy production preferentially over lipids (Nelson and Cox, 2004), and this would be particularly true in cephalopods, which have a vigorous protein-based metabolism (Lee, 1994). ...
Martins, R. S., Roberts, M. J., Chang, N., Verley, P., Moloney, C. L., and Vidal, E. A. G. 2010. Effect of yolk utilization
on the specific gravity of chokka squid (Loligo reynaudii) paralarvae: implications for dispersal on the Agulhas Bank, South Africa. – ICES Journal of Marine Science, 67: 1323–1335.
Specific gravity is an important parameter in the dispersal of marine zooplankton, because the velocity of currents, and therefore
the speed of transport, is usually greatest near the surface. For the South African chokka squid (Loligo reynaudii), recruitment is thought to be influenced by the successful transport of paralarvae from the spawning grounds to a food-rich
feature known as the cold ridge some 100–200 km away. The role of paralarval specific gravity on such transport is investigated.
Specific gravity ranged from 1.0373 to 1.0734 g cm−3 during the yolk-utilization phase, implying that paralarvae are always negatively buoyant, regardless of yolk content. The
data were incorporated into a coupled individual-based model (IBM)—Regional Ocean Modelling System model. The output showed
that dispersal was dominantly westward towards the cold ridge. Also, modelled paralarval vertical distribution suggested that
hydrodynamic turbulence was an important factor in dispersal. The negative buoyancy of early chokka squid paralarvae may reduce
the risk of paralarvae being advected off the eastern Agulhas Bank and into the open ocean, where food is less abundant, so
specific gravity may be important in enhancing the survival and recruitment of chokka squid.
... Lipids in the egg yolk are a highly efficient source of energy in a way that they contain more than twice the energy of carbohydrates and proteins (Lee 1991). Lipids play a significant metabolic role and supply energy to support embryonic development and growth; they are also a source for providing the structural and physiological integrity of cellular membranes. ...
The mangrove horseshoe crab, Carcinoscorpius rotundicauda, is an Asian species found in Malaysia. This ancient arthropod has a long incubational period during which it depends on various energy sources for both embryogenesis and organogenesis. This study describes the trend of energy utilization from the endogenous reserves by the developing embryos from 0 to 40 days of incubation (until the hatching of the larvae). The dry weight, insoluble protein, carbohydrate, glycogen and lipid showed a declining trend from 0 to 40 days of incubation, whereas the wet weight, water content, ash content and soluble protein showed an increasing trend. Selected micro-elements such as Cu, Fe and Zn also demonstrated an interesting trend in the developing eggs when the egg mass was subjected to inductively coupled plasma mass spectrometry analysis, where these elements showed a high correlation with the moulting stages and egg development. Maximum variations within the micro-elements were observed during the 1st (10 days after fertilization) and 2nd (35–36 days after fertilization) moulting stages within the developing eggs. This study clearly indicated that the moulting cycles of C. rotundicauda during embryonic development influence energy utilization in the form of carbohydrates, lipids, proteins, glycogen and other micro-elements.
... The only exceptions to this pattern in the Decapoda are the Dendrobranchiata, which release their eggs directly to the water column. Embryogenesis is supported by endogenous yolk reserves that provide developing embryos with the necessary nutrients to maintain their physiological processes during development and growth (Lee 1991; Lee et al. 2006 ). Nutrients are gradually used throughout embryogenesis according with embryos' requirements, which can vary qualitatively and quantitatively within populations of the same species and among species (Sargent et al. 1989). ...
Offspring quality of decapod crustaceans has been widely studied, with special emphasis on the sources of variability determining embryonic and larval quality. Nevertheless, maternal provisioning has commonly been overlooked as a potential source of offspring within-brood variability. In the present study, the existence of variable maternal provisioning was assessed through the analysis of the fatty acid (FA) profile of newly extruded embryos from different regions of the brooding chamber of Homarus gammarus. Significant differences in the FA profile of embryos sampled from different pleopods and sides of the brooding chamber were recorded. Significant deviations of the overall mean of each surveyed female were also observed for essential FA, particularly 20:4n-6, 20:5n-3 and 22:6n-3. Lipid energy available to fuel embryogenesis also varied among embryos sampled from different regions of the brooding chamber. Results suggest variable female investment at oocyte production, which may be amplified during the incubation period of developing embryos by differential lipid catabolism. For the first time, maternal provisioning is evidenced as an additional source for within-brood variability in the FA profile of embryos.
... Phospholipids in Calanus spp. are primarily structural lipids associated with membranes but also an important component of egg yolk (Lee 1991), thus indicating a potential increase in the size or number of cells like oocytes and in maturation and EP, as proposed by Ohman & Runge (1994). Ohman & Runge (1994) also found an increase in C. finmarchicus phospholipid content from March to June, and found that an egg contained 47 ng of phospholipids. ...
... Phospholipids in Calanus spp. are primarily structural lipids associated with membranes but also an important component of egg yolk (Lee 1991), thus indicating a potential increase in the size or number of cells like oocytes and in maturation and EP, as proposed by Ohman & Runge (1994). Ohman & Runge (1994) also found an increase in C. finmarchicus phospholipid content from March to June, and found that an egg contained 47 ng of phospholipids. ...
This is the first high temporal-resolution study in Disko Bay covering population dynamics, grazing, reproduction, and biochemical composition of 3 dominating copepod species (Calanus finmarchicus, C. glacialis and C. hyperboreus) from late winter to midsummer in 2008. C. finmarchicus and C. glacialis ascended to the surface layer at the onset of the spring phytoplankton bloom, followed by C. hyperboreus 2 wk later. C. finmarchicus spawning occurred during the bloom and post-bloom period, partially fueled by wax esters. C. glacialis commenced spawning before the bloom, yet it was greatly stimulated when food became available. However, feeding and reproduction was terminated after the main bloom despite the presence of food. In terms of feeding, this was also the strategy for C. hyperboreus. Between pre-bloom and post-bloom, C. finmarchicus showed an increase in carbon, nitrogen, and phospholipid content but a decrease in total lipid content. This was likely the result of protein synthesis, oocyte maturation, and spawning fueled by wax esters and by feeding. C. glacialis showed a similar pattern, although with an increasing total lipid content from pre-bloom to post-bloom, and an increasing wax ester and decreasing phospholipid content after reproduction was terminated. C. hyperboreus showed greatly increased content of carbon, nitrogen, and all lipid classes between the pre- and post-bloom periods. Hence, C. finmarchicus commenced feeding and spawning at the onset of the bloom and continued throughout the remaining study period. Both C. glacialis and C. hyperboreus females refueled their storage lipids (wax esters) during the bloom and post-bloom period, suggesting that they may spawn in an additional year.
... Egg yolk proteins, lipids and carbohydrates in are the major sources of energy and structural compounds for embryo development. In aquatic invertebrates, these compounds are usually associated, forming lipo-glyco-carotenoprotein complexes called lipovitellins (LV) that provide for embryo nutrition and also for larvae metabolic needs from hatching up to the moment they start feeding on external sources (Lee, 1991). Lipovitellins originate from vitellogenins (VTG), which are circulating lipoproteins in vitellogenic females. ...
... The gonads were extremely rich in PL, which must result from a conversion of storage lipids into PL via FFA. PL are accumulated in gonads for egg production since eggs have yolks with lipovitellin, a lipoprotein with approximately equal amounts of protein and phospholipids (mainly phosphatidylcholine), as known from other zooplankton species (Lee 1991). ...
During various seasons from May 2001 until July/August 2003, the lipid dynamics of the pteropod Clione limacina from Kongsfjorden, Svalbard, were investigated with respect to ontogenetic development and life-cycle. Polytrochous larvae, which were dominant in spring (April, May), composed the lipid-richest specimens of the population, with total lipid of about 50% of dry mass (%DM). Major lipid classes were triacylglycerols (TAG) and 1-O-alkyldiacylglycerol ethers (DAGE), accounting on average for 53.1 and 21.9% of total lipid, respectively. Until summer, larvae grew to adults by utilising their storage lipids. In July/August, lipids were depleted to about 10%DM due to maturation and reproduction. Almost all animals in autumn (September) were mature and able to replenish their lipid deposits by accumulating DAGE (26.7%) and TAG (39.6%). This is probably the prerequisite for successful overwintering.
Principal component analysis (PCA), based on the fatty acid compositions, revealed ontogenetic differences between polytrochous larvae, and small and full-grown adults. Higher proportions of 18:4(n-3) and 14:0 were found in polytrochous larvae and smaller adults during spring. Both fatty acids were highly significantly correlated with the proportions of TAG, which were used for growth and development because they are presumably easier to metabolise. PCA also divided C. limacina specimens into DAGE-rich and DAGE-poor. We suggest that DAGE are a long-term energy store and hypothesise that they are necessary during periods of food scarcity, but may also serve as an energy source for reproduction. The fatty acids 17:1(n-8), 15:0, 16:1(n-7) and 18:1(n-7) were significantly correlated with the proportion of DAGE but not with TAG. These fatty acids, which do not originate from their only prey, Limacina helicina, are synthesised de novo. Their abundance reflects an efficient lipid production by C. limacina. Based on the results of lipid biosynthesis and accumulation in combination with the population structure, we suggest that C. limacina has at least a 2-year life-cycle in Svalbard waters.
... The eggs contain lipids mostly in the form of phospholipids, which are essential for membranes and cell differentiation. A major portion of the phospholipid is certainly associated with membranes, but part of it may be also in the lipovitellins in which phosphatidylcholine is the major lipid component (Lee 1991). Due to their ability to feed directly after hatching, veligers are probably not dependent on neutral lipids provided by the eggs. ...
The sea butterfly Limacina helicina was collected from May to September 2001 in Kongsfjorden, Spitsbergen, to investigate population structure and body and lipid composition with regard to life cycle and reproductive strategy. Veligers and juveniles were only found in late autumn and spring, whereas females occurred from July to September. The size of the females increased until mid-August and decreased in September. Dry and lipid mass were closely related to size; dry mass increased exponentially and lipids linearly with size. The lipid content was highest in veligers (31.5% of dry mass) and juveniles (23.6%) but low in females ( L. helicina has a one-year life cycle with peak spawning in August and over-winters as veligers that may grow to juveniles during the winter period. They metamorphose into juveniles during spring, develop to males in early summer, and mature into females in July and August.
... An important step in the evolution of many multicellular organisms was the development of the oviparous life strategy, where embryogenesis occurs independently of the maternal body and, consequently, growth and energy provision are dependent on endogenous yolk reserves (e.g. lipovitellins and lipid droplets in crustaceans; Lee 1991; Lee et al. 2006 ). During this lecithotrophic phase of ontogeny (prior to exogenous feeding), larvae must obtain all the nutrients required for homeostasis and development from the eggs. ...
Variations in embryo size and fatty acid (FA) dynamics during embryogenesis were evaluated in deep-sea pandalids and portunid
swimming crabs from the Portuguese continental margin and Madeira Island slope and compared with previous data on neritic
and deep-sea lobsters and shrimps (collected between February 2001 and March 2004). Inter-specific variations in embryo size
seem to be dictated primarily by phylogeny rather than by differences in reproductive or early life history traits. FA reserves
were significantly correlated with embryo size (P<0.001). Principal component analysis revealed differences among three groups (1—neritic caridean shrimps, 2—deep-sea pandalids
of the genus Plesionika, and lobsters, 3—portunid crabs and the deep-sea pandalid Chlorotocus crassicornis, Costa 1871). Group 1 was clearly separated by PC1 mainly due to the higher percentage of essential C18 (linoleic and linolenic acids) and C20 (namely eicosapentaenoic) polyunsaturated FA (specific markers of primary producers). PC2 separated Group 2 from Group 3
due to differences in the percentage of several saturated FA (including odd-numbered FA—bacterial markers) and C18 monounsaturated FA (namely 18:1n−9, a general marker of carnivory). Therefore, these differences among groups seem to result from distinctions in diet and
ecological niche. Intra-specific differences in FA composition between western and southern Plesionika martia martia (A. Milne-Edwards, 1883) populations may reflect higher water temperatures on the south sub-tropical coast. Lobster embryonic
development was more demanding of lipid energy than that of the other decapod species, which may reflect an evolutionary trend
in decapod taxa related to an increasing degree of lecithotrophy. However, a lower FA catabolism can be interpreted as an
enhanced independence of the newly hatched larvae from external energy sources. Higher FA content at hatching and, as a consequence,
a greater independence from the external environment should increase the chances of larval survival.
... In addition, from 0 to 5 DPH in O. maya the structures that dominated the architecture of the digestive gland were the yolk platelets, which are the source of nutrients for the maintenance and development of the embryo and hatchling during the first posthatching days. These large yolk platelets are filled with yolk proteins (vitellin), which are phospho-lipo-glycoproteins derived from a larger maternal precursor, vitellogenin (Vg), which has been extensively studied in several organisms due to its role in reproduction, breeding and digestion (Lee 1991, Matozzo et al. 2008. Boletzky (1975) observed that, during development, the inner yolk sac is in contact with a large blood sinus, which persists in adult octopods as the sinus mesentericus. ...
The cephalopod digestive gland (DG) is responsible for enzyme production as well as nutrient and lipid storage. Octopus maya (Mollusca: Cephalopoda) is a holobenthic octopus species with aquaculture potential. To develop a balanced food for the rearing of this octopus, it is necessary to understand its digestive physiology. We performed histological studies on the structural change of the DG (cytological ontogeny) associated with age (from 0 to 30 d posthatching, DPH) and food (postprandial change in 120 DPH juveniles). Early ontogeny of DG was defined in 3 stages: (1) yolk platelets stage (0 to 5 DPH), (2) transition stage (6 to 10 DPH) and (3) heterolysosomes (food reserves) stage (>12 DPH). In Stage 1, the DG had anatomically undifferentiated tubules, but was filled with yolk platelets. The tubular structures developed lumen by 5 DPH. Stage 2 (starting at 6 DPH) corresponds to mixed exogenous and endogenous feeding. At that time, the yolk platelets were gradually consumed until completely exhausted at 9 DPH. At the onset of Stage 3, the DG structure was completely tubular, exhibiting digestive cell microvilli and other cellular features typical to octupus DGs. During exogenous feeding (12 DPH and onward), acidophilic secretory lysosomes, heterolysosomes and some heterophagosomes appeared on DG cells. O. maya has long digestive cycles in which the extracellular and intracellular digestion can take up to 8 h. Although the ecological implications of this information for aquaculture will still have to be proven, results demonstrated that O. maya is an energetically efficient species and thus suitable for rearing in captivity.
... The properties of crustacean hemolymph lipoproteins differ markedly from those of Ž . higher animals Lee, 1991;Komatsu et al., 1993 , and lipid transport in crustaceans is Ž . suggested to be unique Teshima and Kanazawa, 1980b , especially relative to the role of PL in cholesterol transport. ...
Two 6-week experiments were conducted in recirculating systems to determine dietary requirements of Litopenaeus vannamei for phospholipids (PL) and cholesterol, and their potential interaction. A 3×4 factorial design consisting of three cholesterol levels (0%, 0.2%, and 0.5% of diet) and four PL levels (0%, 1.5%, 3.0%, and 5.0% of diet) provided by de-oiled soybean lecithin (SL) was applied. Overall survival was 97.7% with no significant difference among dietary treatments. There was a highly significant interaction between PL and cholesterol on shrimp growth (P=0.0001). Dietary cholesterol at 0.2% or 0.5% gave similar shrimp growth at any given level of PL.
... Invertebrate circulating lipoproteins have been studied mainly in the phyla Arthropoda and Mollusca. Lipoproteins of crustaceans, the most studied group of aquatic arthropods, are well known and have been described and reviewed by Lee and Puppione (1978), Chang and O'Connor (1983) and Lee (1991). In terrestrial arthropods, the mechanisms of lipid circulation are well known in insects i.e. ...
It has been already reported that most hemolymphatic lipids in the spider Polybetes pythagoricus are transported by HDL1 and VHDL lipoproteins. We studied in vitro the lipid transfer among midgut-diverticula (M-diverticula), and either hemolymph or purified lipoproteins as well as between hemolymphatic lipoproteins. M-diverticula and hemolymph were labeled by in vivo (14)C-palmitic acid injection. In vitro incubations were performed between M-diverticula and either hemolymph or isolated lipoproteins. Hemolymph lipid uptake was associated to HDL1 (67%) and VHDL (32%). Release from hemolymph towards M-diverticula showed the opposite trend, VHDL 75% and HDL1 45%. Isolated lipoproteins showed a similar behavior to that observed with whole hemolymph. Lipid transfer between lipoproteins showed that HDL1 transfer more (14)C-lipids to VHDL than vice versa. Only 38% FFA and 18% TAG were transferred from M-diverticula to lipoproteins, while on the contrary 75% and 73% of these lipids, respectively, were taken up from hemolymph. A similar trend was observed regarding lipoprotein phospholipids. This study supports the hypothesis that HDL1 and hemocyanin-containing VHDL are involved in the uptake and release of FFA, phospholipids and triacylglycerols in the spider P. pythagoricus. The data support a directional flow of lipids from HDL1 and VHDL suggesting a mode of lipid transport between lipoproteins and M-diverticula.
... In crustaceans, as in most marine invertebrates, the major component of egg yolk is lipovitellin, which is comprised of proteins and lipids (Lee, 1991;Walker et al., 2006). ...
The cold Humboldt Current (HC) allows for a wide distribution range of the crab Cancer setosus MOLINA, 1782 along the Pacific Coast of Peru and Chile (~2 degrees S to 46 degrees S). Life of this cold-water adapted brachyuran crab in the HC is challenged by high interannual temperature variability influenced by El Nino Southern Oscillation (ENSO). Early life-history stages may be particularly sensitive to abrupt changes in temperature and may thus represent physiological bottlenecks in species distribution. The present study aims at identifying the effects and limits of latitudinal and ENSO temperature variation on reproduction and early life history traits of C. setosus. The number of annual ovipositions was calculated from monthly frequencies of ovigerous females and the temperature dependent duration of egg development (65 days at 12 degrees C to 23 days at 22 degrees C). In Ancud, Chile (41 degrees S) one annual clutch is laid in late winter, while in Concepcion (36 degrees S), slightly higher winter temperatures (12 degrees C vs. 10 degrees C in Ancud) enable for reproduction throughout the year (~3.6 clutches per year). However, towards the species northern range the annual number of clutches decreases to ~2 in Coquimbo (29 degrees S) and ~1 in Casma (9 degrees S), which is attributed to an increase in metabolic costs of life under warmer conditions. Temperature dependent changes in the reproductive cycle were confirmed by observations on crabs reared in aquaria in Antofagasta (23 degrees S, 16-22 degrees C) and in Puerto Montt (41 degrees S, 12, 16 and 19 degrees C) for up to 10 and 5 months, respectively. The decreasing interbrood periods at higher temperatures are accompanied by a decrease in the energetic investment per offspring. Eggs laid at low temperatures in Puerto Montt (~11 degrees C) contained 32% more energy, measured as dry mass, carbon, nitrogen, and fatty acid content and volume, than eggs of equal sized females produced at ~19 degrees C in Antofagasta. However, when exposed to warmer temperatures, seasonally in the field and under aquaria conditions, females in Puerto Montt went on to produce smaller eggs in subsequent egg masses. The larger investment per offspring at lower pre-oviposition temperature is discussed to be adaptive by providing the hatching larvae with a higher amount of energy needed for their prolonged development at lower temperatures. Female investment in egg traits is not carried over 1:1 into larval traits. Throughout egg development almost twice as much of the total of fatty acids was used for metabolism in eggs incubated at 12 degrees C compared to 19 degrees C (-1.12 and -0.62 microgram/egg, respectively). The observed high degree of reproductive plasticity is discussed as a key to the species' wide distributional range and to sustaining exploitable populations under conditions of high and unpredictable environmental stochasticity. However, the current level of uncontrolled fishing pressure and the low enforcement of the minimum legal size of 120 mm carapace width (CW) have caused Chilean C. setosus catches to decline for more than a decade. Next to a strict enforcement of the minimum CW, the creation of no-fishing areas is recommended, for (i) allowing recovery of the stock and maintaining larval supply, (ii) studying population dynamics and the ecological role of this benthic predator in the absence of fisheries mortality, and (iii) preventing likely long-term effects of size selective extraction of large, fast-growing specimens on the populations gene-pool ('fisheries-induced evolution').
The snow crab ( Chionoecetes opilio ), SC, is a newly established species in the Barents Sea. The snow crab fishery has established itself as a new and profitable industry in Norway in the last decade. The fishery started as a year-round fishery, without any information of possible seasonal variations in the quality of the product. In 2017 a total allowable catch was established by the Norwegian government, and the fisheries were subsequently closed during the summer months. In order to optimize fishing times, and to evaluate this growing industry in the Barents Sea, seasonal variations of the meat content of the clusters, as well as variations in content and quality of co-products were investigated, aiming to identify the seasons where the exploitation of different products from SC can be most profitable. The results show seasonal variations in meat content and in composition of co-products. The highest co-product quantities and meat content are from February to April, followed by a period from June to September with decreasing meat and co-products. Our recommendation is to capture the SC in the winter–spring period in the Barents Sea, supporting the current situation and creating most value for the fisheries.
Si bien existen más de 35.000 especies de arácnidos, la información respecto al sistema de transporte de lípidos es muy escasa, se han descripto lipoproteínas de alta y de muy alta densidad (HDL y VHDL) en solo tres especies (Polybetes pythagoricus, Eurypelma californicum y Latrodectus mirabilis), con fosfolípidos (PC), diglicéridos (DAG) y triglicéridos como lípidos predominantes. En dos de estas especies (P. pythagoricus y L. mirabilis), se encontró que la hemocianina participa en el transporte de lípidos. En el presente trabajo identificamos y aislamos las lipoproteínas hemolinfáticas de la tarántula Grammostola rosea, y realizamos una caracterización de sus componentes proteicos, lipídicos y de ácidos grasos. Luego de la ultracentrifugación en gradiente de densidad sobre un colchón de BrNa de una densidad de 1,28g/ml, se observó que G. rosea posee dos lipoproteínas, una de alta densidad (HDL), con una densidad entre 1,13-1,15 g/ml, y una de muy alta densidad (VHDL) de 1,24 g/ml. HDL posee un 60% de lípidos y VHDL un 7%, siendo la fosfatidilcolina (PC) y DAG los lípidos predominantes. En relación a los ácidos grasos, en ambas lipoproteínas se encuentran principalmente el 18:1 y 16:0 en un 27% y el 18:2 y 18:0 en un 15%. Como resultado de la electroforesis nativa en geles de poliacrilamida con gradiente de poro 4-23%, se observo en la HDL una bandade 644 kDa y en condiciones disociantes una banda de 154 y otra de 107, sin mostrar diferencias en presencia o ausencia del agente reductor. En el caso de VHDL, en condiciones nativas se observan bandas de 694, 383, 369, 84 y 67 kDa. En condiciones disociantes se encontró un patrón muy similar al ya descripto para la araña P. pythagoricus, en el cual se ven dos bandas de 123 y 103 kDa y una de 70 kDa, que podrían ser dos proteínas no respiratorias y el monómero de hemocianina. Tampoco se observó la presencia de puentes disulfuro. Es destacable que éste es el primer reporte donde se describen los ácidos grasos de lipoproteínas hemolinfáticas de arácnidos.
To fully elucidate the action of crustacean hormones, or their agonists, on vitellogenesis and reproduction, it has become increasingly important to develop sensitive assays that indicate a stimulatory or inhibitory effect on easily measured endpoints. Because of the relative abundance of vitellin in crustacean yolk and the ease with which it can be isolated, this protein makes an excellent model for studying the mechanisms that control and regulate reproduction. Vitellin was purified from eggs of adult female Lepidophthalmus louisianensis, Palaemonetes pugio, Rhithropanopeus harrisii, Americamysis (Mysidopsis) bahia, and Uca panacea which were collected from estuarine localities in Santa Rosa Sound, Gulf Breeze, Florida during late spring and summer of 1999. The purified proteins were used to immunize rabbits for polyclonal antibody production. Specificity of antisera was tested against respective vitellins by Western blotting. These antisera will be used to develop assays useful to the study of reproductive endocrinology, vitellogenesis, and toxicology.
In aquatic invertebrates, lipids represent an important source of stored energy, as well as structural components of cellular membranes and other lipoprotein complexes. In the freshwater shrimp Macrobrachium borellii, we demonstrated that the hepatopancreas, also known as midgut gland, has a high capacity for triacylglycerol biosynthesis, storage and breakdown. When radioactive palmitic acid was injected in vivo, most of the label was transported to the hepatopancreas, where triacylglycerol were actively synthesized. The enzymatic activity that initiates glycerolipid synthesis, glycerol-3-phosphate acyltransferase, is located in the mitochondria. In contrast, triacylglycerol synthesis in hepatopancreas microsomal fraction follows the monoacylglycerol pathway. Even though triacylglycerol count for the major lipid class (up to 80% of the total lipids), phosphatidylcholine is exported from the hepatopancreas to other tissues and transported in hemolymph as a high-density lipoprotein (HDL), suggesting that triacylglycerol are stored in the hepatopancreas for energy supply or lipid remodeling. M. borellii's HDL lipid moiety is composed mainly of phosphatidylcholine with minor quantities of cholesterol and triacylglycerol. Lipid transference between hepatopancreas and HDL was studied in vitro, confirming that HDL releases free fatty acids to the hepatopancreas, whereas phosphatidylcholine and other phospholipids are liberated from the hepatopancreas to HDL. Proteins, lipids and carbohydrates present in the vitellus of eggs are important energy and building block sources for the embryo development in ovipara. In aquatic invertebrates, these compounds are usually associated forming lipoproteins called lipovitellins (LV) that function as nutrient sources for the development of the embryo and also satisfy the metabolic larvae needs from their birth to the moment they start feeding on external sources. In M. borellii and other crustaceans, LVs are high-density lipoproteins with phosphatidylcholine as the major lipid and minor quantities of other lipids like triacylglycerol and phosphatidylethanolamine. LVs are originated from a plasma lipoprotein restricted to ovogenic females: vtellogenin (VG). M. borellii's VG lipids are similar quantities of phosphatidylcholine, sphingomyelin, triacylglycerol and phosphatidylethanolamine. During vitellogenesis, VG is endocyted into the ovary, where it is processed and changed into LV. Compared to VG, LV has twice as much phosphatidylcholine as the other lipid classes and less sphingomyelin, suggesting that the lipoprotein processing in the ovary provides LV with different lipid domains specific for its biological function. Due to the fact that some of LV apolipoproteins have been detected inside the developing embryo, it was concluded that LV was consumed. LV transfers to the embryo mainly the lipids loaded inside the ovary (mostly phosphatidylcholine), together with proteins to feed the embryos. Further studies are needed to determine the lipid transference mechanisms involving the lipoproteins with lipid donor and receptor organs. However, our knowledge about lipid transport and metabolism in crustaceans has evolved in the last few years regarding both plasma and yolk lipoproteins; it sets ground for understanding the lipoprotein function in reproduction and embryo development.
Lipids due to its hydrophobic nature are transported in the hemolymph mainly by lipoproteic fractions. In the present work we studied the lipoproteic fractions present in the hemolymph of the spider Grammostola rosea. Through ultracentrifugation two lipoproteic fractions are isolated, one of high density named Gr-HDL (δ = 1.13-1.15 g/ml) and the other of very high density called Gr-VHDL (δ = 1.24-1.27 g/ml) Gr-VHDL in hemolymph is majority in relation to Gr-HDL. In this sense Gr-VHDL fraction has 98.6% of hemolymphatic proteins, and 89.3% of lipids presents in the hemolymph. Both lipoproteic fractions possess phospholipids such as majority lipids (phosphati-dylcholine and phosphatidylethanolamine) and 18:1, 16:0, 18:2 and 18:0 as the major fatty acids. In order to confirm the role played by lipoproteic fractions in vitro assays with different 14 C-lipid were performed. It was observed that Gr-VHDL takes up mainly free fatty acids and triacylglyce-rols unlike that observed for Gr-HDL in relation to phosphatidylcholine. Through electrophoresis it was observed that Gr-VHDL has three proteins: a predominant band of 68 kDa and two others of 99 and 121 kDa. Gr-HDL displayed a predominant band of 93 kDa, and other minority of 249 kDa. In conclusion, this study reports lipid characterization of the lipoproteic fractions present in the hemolymph of the tarantula, G. rosea. The role of each lipoproteic fraction in relation to lipid uptake is sustained by in vitro assays. Similarities and differences are found when it is compared to lipoproteins of only the three species of spiders studied.
The concentration of vitellogenin (Vg) in the hemolymph of Penaeus semisulcatus was found to in- crease from an average of 50 pg ml-' to 439 pg ml-' in female shrimp during ovarian development. The most significant increase in Vg occurred concomitant with the increase in the vitellin (Vt) content of oocytes with an average diameter (AOD) ranging between 150 and 250 pm. The amount of Vt in the oocytes was found to in- crease linearly from a mean of 0.0 126 mg to 4.55 mg per gm body weight. However, the percentage of Vt in the total protein was found to decrease, from 67% in ovaries with AOD of 150-250 pm, to 39.7% in ovaries with AOD of 350 pm or larger. The volume of the hemolymph was found to be 0.4 ml per gm body weight and did not change significantly during ovarian development. Assuming that Vg in the hemolymph represents either an extraovarian origin of Vt or an active secretion from the ovary, a turn- over rate of two to three times per day was calculated over one full cycle of oocyte development. However, during the most significant increase in Vt in the ovary (in ovaries with AOD of 150-250 pm), the turnover rate in the he- molymph could reach seven to eight times per day. The results lead to the conclusion that the contribution of Vg to the formation of Vt in the ovary is quantitatively in- significant.
Previous published results (Hall et al., 1995) showed that two plasma proteins involved in the immune response in the crayfish (Pacifastacus leniusculus) are lipoproteins, suggesting an apparent functional association between lipid transport and the immune response system in crustaceans. The crayfish Astacus astacus is sensitive to a disease caused by the fungus Aphanomyces astaci, which is responsible for high mortalities in the natural environment. Since vitellogenesis is accompanied by a massive accumulation and transport of lipids to ovaries, the present study examines the effect of the crayfish plague fungus A. astaci on lipid transport during sexual development in the crayfish A. astacus. Comparison of the plasma lipid composition between animals sampled before and at the end of the ovarian development cycle revealed that mature females contained more lipids than males or immature females. The high-density lipo-protein (HDL) hemolymph fractions contained four to seven times more lipids than the very high-density lipoprotein (VHDL) fractions; triacylglycerols (TAG) were detected only in the HDL of females. There were no significant changes in hemolymph lipid levels in vitellogenic females subjected to an experimental fungal infection. However, in males exposed to the same experimental conditions, there was a significant decrease in phospholipids (PL) concomitant with an increase in diacylglycerols (DAG) and cholesterol (CH). No differences were observed in the lipid content of either the hepatopancreas (of males and females) or the ovaries due to infection, except a slight decrease in the ovarian PL level. Clotting protein was found relatively more abundant in plasma samples obtained from infected animals after subjecting them to polyacrylamide gel electrophoresis under native conditions. The results of the present study suggest that long-term exposure to a sub lethal dose of the fungus may allow in future studies, a better evaluation of the effect of an infection on lipid composition in shrimp plasma and tissue samples.
Concurrent morphological, anatomical and physiological changes took place during the first reproductive cycle in the Australian red-claw crayfish Cherax quadricarinatus, which prepared the female for spawning and holding of the newly deposited eggs. The endopod became longer and wider than the exopod and developed a mixture of plumose and long thin simple (ovigerous) setae. Small oocytes (0.24±0.05 mm) were present in the immature ovary. The growing ovary contained two distinct oocyte populations: one consisted of small (0.55±0.07 mm), barely growing oocytes, while the other consisted of large oocytes, which increased in size continuously (0.73 to 2.55 mm) until egg laying took place. A gradual change in the relative abundance of ovarian polypeptides occurred until the late vitellogenic stage (large oocytes < 1.8 mm). Three predominant female-specific, SDS-PAGE separated, polypeptides were observed (103, 78 and 73 kDa) that may represent vitellin subunits. The most abundant carotenoid in the ovary was astaxanthin, while β-carotene was present at a lower concentration. The strong correlation between the increasing diameter of the oocyte and the concentration of astaxanthin in the ovary and in the hemolymph suggested an association of astaxanthin with vitellin and vitellogenin.
1.1. LP1, a high density lipoprotein common to both sexes of the penaeid shrimp Penaeus semisulcatus was isolated as the upper yellow-brown layer resulting from ultracentrifugation of male hemolymph. The hemolymph solution was adjusted to a hydrated density of 1.2 g/ml. A similar HDL fraction was isolated from the hemolymph of vitellogenic females containing, in addition to the LP1, the female-specific lipoprotein vitellogenin (Vg).2.2. Hemocyanin (Hcy), the oxygen carrier of crustaceans was isolated as pellet, resulting from the same ultracentrifugation. Hcy was identified by its blue color, its copper content and its characteristic absorbance spectrum. It is the most abundant hemolymph protein, and is composed of two major subunits of 85 and 95 kD.3.3. Polyclonal antibodies were raised in rabbits against Hcy and LP1. The antisera were found to be specific and no crossreaction was observed between them and an anti-Vg/Vt serum prepared during earlier studies. All three antisera proved to be suitable research tools for the identification of these three physiologically important proteins (Vg, LP1, Hcy).
Four major yolk proteins, designated as vitellins (Vns) Macr-VnA, B, C, and D, were extracted from mature ovaries of Macrobrachium rosenbergii. These were purified to homogeneity by reversed-phase high performance liquid chromatography (HPLC) employing a unique separation system based on the hydrophobic properties of the Vn molecule. Using standard techniques of protein sequencing, more than 33 N-terminal and 57 internal amino acid residues were determined for each of the four Vns. The cDNA fragments encoding the four Vns were amplified by PCR using degenerate oligonucleotide primers derived from the N-terminal and internal amino acid sequences. These cDNA fragments were cloned, sequenced, and used as probes to examine the transcription of mRNAs encoding the four Vns. Significant accumulations of these mRNAs were observed in female hepatopancreas only, while mRNA expression was not detected in male hepatopancreas or any other female tissue including ovary, subepidermal adipose tissue, gill, and muscle. This is the first occasion in Crustacea in which multiple Vns were demonstrated to be synthesized simultaneously in a single tissue. J. Exp. Zool. 287:413–422, 2000. © 2000 Wiley-Liss, Inc.
The effect of fenithrotion (FS) on the functionality of two models of crustacean lipoproteins was studied. Models used were a high density plasma lipoprotein (HDL) that is involved in the lipid–tissue exchange, and a lipovitellin (LV), the main source of embryo nutrients, which presents two forms only distinguishable in its lipid composition. The relative influence of lipid and apoprotein compositions on the FS effect in lipid transfer was comparatively evaluated using liposomes prepared with lipids obtained from both lipoproteins. FS treatment of HDL modified the transfer of lipids to and from hepatopancreas, diminishing the uptake of phosphatidylcholine and triacylglycerols and increasing its capacity to release both lipids to the tissue. Likewise, FS increased the transfer of phophatidylcholine to the embryonic tissue from both LVs and from liposomes. It was assessed that apoproteins are involved in the transfer of phosphatidylcholine to tissues, though they are not involved in the changes produced by FS concerning the affinity of this lipid to lipoprotein systems.
Blue crab ovaries rapidly increased in weight during the 30 days after the terminal molt into adulthood. Oocytes isolated from ovaries during this period increased in diameter from 40 to 201 μm. The concentrations of lipovitellin, a high density lipoprotein found in oocytes, were determined by a competitive ELISA procedure using a monoclonal antibody against one of the lipovitellin peptides. Lipovitellin and lipid droplets were minor components in the immature ovaries and oocytes but increased in concentration to become the major components of the mature ovaries and oocytes. In mature oocytes (201 μm diameter) lipovitellin concentrations accounted for 35 and 95% of the total oocyte protein and soluble oocyte protein, respectively. In mature oocytes the total lipid, lipovitellin lipid, and lipid droplet concentrations were 510, 240, and 140 ng/oocyte, respectively. Sections of ovaries and hepatopancreas at different stages of maturation were probed with the anti-lipovitellin antibody. In small immature oocytes, where no yolk was present, the immunoreactivity was confined to perinuclear yolk complexes. The immunoreactivity of more mature oocytes was associated with globular structures in the cytoplasm. Neither ovarian follicle cells nor hepatopancreas cells showed immunoreactivity. Our results suggest that in blue crabs the lipovitellin components are primarily synthesized in the developing oocytes with perinuclear yolk complexes playing an important role in the formation of lipovitellin-rich yolk granules. Scattered collections of presumed phagocytic hemocytes contained immunoreactive granular material in their cytoplasm. We suggest that these hemocytes remove debris from oocytes which fail to reach maturation and carry this debris to the hepatopancreas. © 1995 Wiley-Liss, Inc.
The present research was aimed at studying the synthesis of lipids from 14C-acetate in vitro by ovarian tissue in relation to oogenesis and at examining the binding of newly synthesized lipids to ovarian proteins. Lipid synthesis gradually increased during oogenesis. Fifty percent of the newly synthesized lipids was phosphatidyl choline; triacylglycerols reached 30 to 35%; diacylglycerol was a relatively important component of the synthesized neutral lipids in immature ovaries. Cholesterol was not synthesized. Only saturated (73%) and monounsaturated (26%) fatty acids were labeled. Polyunsaturated fatty acids were not synthesized. Bound lipids in developing ovaries were associated mainly with vitellin. Lipids were bound also to two other proteins in immature ovaries. Binding of lipids to vitellin was observed at the commencement of vitellogenesis. Up to a third of the newly synthesized lipids was bound to vitellin, with triacylglycerols and phosphatidyl choline as the main bound lipids. Peneaus semisulcatus individuals examined in the present study were collected in Haifa Bay, Israel during the years 1990 to 1992.
A procedure was designed to isolate a lipoprotein (Lp) from the hemolymph of juveniles of the white shrimp, Penaeus vannamei Boone, using two high-speed ultracentrifugation steps. The lipoprotein fraction presented a buoyant density of 1.1-1.17g/ml with a peak at 1.14 g/ml. The isolated Lp corresponds to 0.93 and 0.73% of the total female and male hemolymph protein content, respectively. The Lp from males and females consisted of an apoprotein with an apparent molecular weight of 98 kDa as was shown by electrophoresis under denaturing and reducing conditions and it is a glycoprotein that contains mannose. In the hemolymph of both males and females one main native form of the Lp was found. The isoelectric point of the Lp was 5.81, but minor forms of different isoelectric points were also found.
Apolipoproteins (APO) were analyzed for molecular mass and specificity of occurrence in hemolymph and eggs. Hemolymph donors were males and both ovigerous and non-ovigerous females. Total lipoprotein (LP; exclusively high-density LP) was fractionated into subclasses by density-gradient centrifugation; selected subclasses were delipidated and the APO subjected to electrophoresis under denaturing conditions. Antisera were raised against the isolated APO of both males and females and used for tests of cross-reactivity in Western biots. Principally three protein units were identified (molecular masses: 185, 100 and 84 kDa). Each occurred in the APO of each HDL subclass, in the hemolymphs of males and all females and in eggs. The antisera cross-reacted between all groups. Similar findings were obtained in a less complete study of APO in the blue crab, Callinectes sapidus. Thus, in analyses of isolated APO from two crab species, no evidence could be found for occurrence of a “female-specific protein” (FSP). FSP has been defined as a protein (vitellogenin, more accurately an LP) that is generated only by females active in production of egg yolk LP (vitellin); it is presumed to specialize in transporting yolk lipids. The crustacean literature is surveyed to compare data on APO molecular mass and critically reviewed with regard to FSP.
Due to their hydrophobic nature, lipids are transported in the hemolymph of shrimp by protein–lipid-complexes named lipoproteins. Since cholesterol (Ch) and polyunsaturated lipids must be provided by the diet, and they are stored mainly in the hepatopancreas; a special vehicle is necessary for their mobilization to other tissues. Two types of hemolymph lipoproteins have been isolated from penaeid shrimp. Non sex-specific lipoproteins present in males and females (LPI), and female-specific lipoproteins (LPII or Vg) that occur mainly in mature females undergoing ovarian maturation. This review focuses on current knowledge about penaeid shrimp hemolymph lipoproteins and it compares their protein and lipid constituents. These lipoproteins are of the high density and very high density types. Their lipids are predominantly phospholipids (PL), but sterols, diacylglycerols (DG), triacylglycerols, and hydrocarbons (HC) have also been found. The apolipoproteins are high molecular mass polypeptides. The LPI generally contains a fewer number of apoproteins or subunits than the LPII or Vg.
A high-density lipoprotein (HDL) fraction was isolated from the hemolymphatic plasma of the spider Polybetes pythagoricus by density-gradient ultracentrifugation. Hydrated density (1.13 g/ml), electrophoretic mobility (SDS—PAGE) of apoproteins and lipid classes composition were determined. Lipids were identified by HP-TLC and auxiliary techniques; they were quantified by TLC-FID. The protein moiety is composed of two main apoproteins (250 and 76 kDa, respectively) and several polypeptides of low molecular weight. It resembles the apoliphorins of insects and some other arachnids. The lipid composition differs from most lipophorins. Phospholipids amount to more than 60% of total lipids, while diacylglycerols (2.4%) are supplanted by triacylglycerols (16.5%) as the main circulating energetic lipids.
The effect of serotonin (5-hydroxytryptamine, 5-HT) injection on the ovarian maturation and vitellogenin levels of Fenneropenaeus indicus was investigated. Female shrimp were assigned under as many as five ovarian stages. The neurotransmitter was evaluated at doses of 2.5 × 10− 6, 2.5 × 10− 7 and 2.5 × 10− 8 mol/g live mass. The effect was compared against a control group, which received the injection of the sterile vehicle solution. Serotonin induced ovarian maturation and increased vitellogenin concentrations at a dose of 2.5 × 10− 6 mol/g live mass. Ovarian development and vitellogenin levels were determined during the reproductive and non-reproductive moult cycles in order to examine the relationship between vitellogenesis and moulting. During the reproductive moult cycle, the ovary developed synchronously with the advancement of moulting stages. The results of the present study reveal the possible stimulatory role of serotonin on the ovarian maturation of F. indicus by increasing the vitellogenin levels.
A very-high-density lipoprotein (VHDL) with a density of 1.27-1.29 g/ml was the most abundant lipoprotein in the hemolymph of the sand crayfish Ibacus ciliatus. The VHDL isolated by a density gradient ultracentrifugation consisted of 94% protein and 6% lipid reflecting its high density, and phospholipid was a predominant lipid component. The VHDL had an apolipoprotein of molecular mass 195 kDa and its N-terminal amino acid sequence was identified as follows: LQPGLEYQYRYNGRVAA. This sequence was similar to those of clotting proteins from the spiny lobster Panulirus interruptus and the freshwater crayfish Pacifastacus leniusculus. Transglutaminase and Ca2+ also induced the VHDL to clot. Considering large amounts of VHDL in the hemolymph of sand crayfish, the VHDL not only functions as lipid carrier but plays an important role in the defense process of crustacea.
1.1. The vitellin of Parapenaeus longirostris was isolated from ripe ovaries by gel filtration on Sepharose 6B followed by ion exchange chromatography DEAE-Sepharose.2.2. The vitellin was identified by comparative PAGE of homogenates prepared from undeveloped and from ripe ovaries as determined by histological sections. The purified vitellin showed one glycoprotein band in disc electrophoresis and one precipitation line in immunoelectrophoresis and immunodiffusion.3.3. SDS-PAGE of the purified substance showed two types of subunits weighing 45,000 and 66,000 daltons.4.4. Antiserum prepared against the purified vitellin of P. longirostris reacted with homogenates obtained from ripe ovaries of Penaeus semisulcatus.
Statistical analyses of mean protein and copper concentrations in hemolymph samples from 435 female blue crabs (Callinectes sapidus Rathbun), grouped according to an arbitrary classification of ovary size, indicate that there is a significant increase in protein and copper concentrations of the hemolymph during oocyte maturation.
This paper presents the effects of destalking on the ovarian maturation and lipid compositions of the prawn Penaeus japonicus. The bilateral extirpation of eyestalks induced the ovarian maturation and increased the ovarian lipids with a concomitant decrease in the hepatopancreatic lipids. The increase in ovarian lipids was ascribed mainly to that in triglycerides (TG), phosphatidylethanol-amine, and phosphatidylcholine (PC), whereas the decrease in hepatopancreatic lipids was due mainly to that in TG and PC. These results suggest the transfer of body lipid reserves, particularly hepatopancreatic lipids, to the developing ovaries during the induced ovarian maturation of the prawn. The ovarian lipids, especially neutral lipids, of destalked prawns contained higher propor-tions of monoenes such as 16: 1 and 18: 1, and 22: 6ω3 and lower proportions of 20: 4ω6 and 20:5ω3 than those of non-destalked prawns.
A survey of carotenoid-protein complexes is presented. Distinction is made between astaxanthin-proteins in which the absorption band of the carotenoid is unaltered in shape, and carotenoid-lipoglycoprotein complexes. The proposal by Buchwald and Jencks79 that the carotenoid is twisted about the double bonds of the polyene chain, is discussed and sustained for astaxanthin-proteins. A mode of binding for the carotenoid in these complexes is proposed, involving hydrogen-bonding of keto groups of the polyene to imide groups of peptide bonds of the apoprotein.
Mandibular organs from adult male spider crabs were implanted into the hemocoel of 15 immature females. Controls were sham operated. Two months following implantation, the seven survivors were sacrificed and their mandibular glands and ovaries fixed for electron microscopy. Ovaries of control animals were small, white organs. Ultrastructurally, they revealed little indication of yolk formation and no micropinocytosis. The ovaries of the experimental crabs ranged in color from a pale yellow to a bright red and were enlarged. The ultrastructure of these oocytes showed many signs of active vitellogenesis, including numerous pinocytotic vesicles in the oolemma.
Protein synthesis was measured in ovary and hepatopancreas of intact and eyestalk-ablated fiddler crabs (Uca pugilator) in vitro. A crude extract of eyestalks from the shrimp Penaeus setiferus inhibited ovarian weight gain in eyestalk-ablated crabs. This crude eyestalk extract also inhibited in vitro protein synthesis in ovaries from intact and eyestalk-ablated crabs. A polyclonal antibody to crab vitellogenin was used to measure vitellogenin synthesis in ovaries, hepatopancreas, and hemolymph in vitro. Gonad-inhibiting hormone was partially purified from the crude eyestalk extract. The partially purified material inhibited vitellogenin synthesis in ovarian tissues in vitro.
To clarify the transport mechanism of dietary lipids, the labelling pattern of lipid classes was investigated on the lipids extracted from the intestinal content, hind-gut, hepatopancreas, muscle, and hemolymph after oral administration of [14C] tripalmitin to the prawn, Penaeus japonicus. Besides this, the incorporation of radioactivity into serum lipoproteins was examined. Most of the radioactive serum lipids were associated with high density lipoproteins (HDL2 and HDL3) and very high density lipoprotein (VHDL), but not with low density lipoprotein, chylomicron, and very lowe density lipoprotein. The lipids of HDL2, HDL3, and VHDL contained polar lipids as the major radioactive lipid classes. The above data was discussed in relation to the lipid transport mechanism in the prawn, P. japonicus.
Lipovitellin samples, extracted from yolk platelets of cysts, were applied to SDS-PAGE. A female specific antiserum was raised against the high molecular weight apoprotein lipovitellin alpha-1 (LV-α1) of the lipovitellin complex. This anti-LV-α1 was used in the peroxidase-anti-peroxidase staining method with frontal paraffin sections (of 4μm) of whole embedded Artemia. Females were studied during a complete vitellogenic cycle. The presence of exogenous yolk precursors in the fat storage cells of the thoracopods of female Artemia was demonstrated. The amount of the female specific yolk polypeptides and the number of positively stained cells changes during the vitellogenic cycle. In vitro experiments with S-radiolabelled methionine show the synthesis of lipovitellin-like substances in the fat storage cells of vitellogenic females.
In addition to the ovary, the hepatopanocreas of female decapod crustaceans, Carcinus maenas, and Libinia emarginata is a source of yolk protein. The specific cells in the hepatopancreas that localize vitellogenins on tissue sections are revealed with lipovitellin-specific antiserum. These cells, designated vitellogenocytes, are believed to be responsible for vitellogenin synthesis in the hepatopanocreas. This conclusion is based upon immunolocalization which demonstrates a temporal relationship with vitellogenin synthesis in the hepatopanocreas. Specifically, when the oocytes are most active in vitellogenin uptake, the hepatopanocreas is producing vitellogenins most abundantly. Vitellogenocytes are relatively large and polymorphic, similar to the reserve-inclusion cells that were described by others. Yolk protein was not detected in other cells of the hepatopancreas, male reserve-inclusion cells, or pre-vitellogenic oocytes by the same method of staining. Vitellogenocytes resemble cyanocytes, the source of hemocyanin. Whether the vitellogenocytes and their precursors are related to other populations of hepatocytes, such as cyanocytes, is not known and has not yet been studied.
The mechanism of lipid transport in octopod hemolymph was studied in Octopus tehuekhus. Three lipoproteins were detected, isolated and partially characterized by a variety of methods including TLC, ultracentrifugation and the use of radiolabelled lipids. The lipoproteins, henceforth called “LP-I”, “LP-II” and “LP-III”, have low, high and very high density, respectively. Cholesterol and phospholipids are mainly transported by LP-I and LP-II. Free fatty acids, hydrocarbons and esterified sterols circulate mainly associated with LP-III. Hemocyanin, the oxygen carrier pigment, also seems to play a role in the transport of lipids, being the apoprotein of LP-III.
The electrophoretical analysis from tissues of Penaeus japonicus (Bate) reveals the presence of two major lipoproteins, specific of vitellogenesis-females. The first band, vitellogenin, is obtained from haemolymph proteins; the second, lipovitellin, is extracted from ovarian vitellus. Both have a molecular weight of ≈ 500 000. Vitellogenin is present in the haemolymph of females weighing > 25 g with a gonado-somatic index of 1.8, and it appears ≈ 7 days after removal of their eyestalks. The molecular weight of lipovitellin obtained by electrophoresis is in agreement with that determined with the use of analytical ultracentrifugation (510000). Upon dissociation by sodium dodecyl sulphate, vitellogenin was shown to release five polypeptide subunits showing molecular weights of 150 000, 105 000, 92 000, 86 000, and 76 000. The amino acid composition of ovarian lipovitellin has been determined. The vitellogenin present in haemolymph is immunochemically identical to the oocyte lipovitellin. The use of immunodiffusion reveals during vitellogenesis the presence of vitellogenin in the sub-epidermal tissue, located in the lateral and dorsal hypoderm of the cephalo-thorax and the abdomen of the females.
Ovaries of the penaeid shrimp Penaeus semisulcatus in various stages of oocyte development were incubated in vitro with 14C or 3H leucine. Protein synthesis was measured by TCA precipitation and vitellin specific synthesis by radioimmunoprecipitation. The proteins synthesized were subjected to native or SDS denaturative gel electrophoresis and visualized by fluorography. The results led to the following conclusions: 1) Protein synthesis was found to depend on the concentration of leucine in the culture media. 2) A relatively constant level of vitellin synthesis was observed in ovaries with oocytes ranging in size between 100 and 380 μm. 3) The vitellogenic stage was found to occur in ovaries with oocytes ranging between 100 and 300 μm in size. During this period, 40–60% of the in vitro–synthesized proteins were found to be immunologically identical to vitellin. 4) A decrease in the relative amount of vitellin synthesized was found with the appearance of cortical crypts in oocytes exceeding 300 μm in diameter. 5) The protein immunologically identical to vitellin, which was synthesized in vitro by the ovaries, was found to consist of the subunits found in purified native vitellin. 6) A bioassay system for testing the effect of various factors on vitellin synthesis is suggested by in vitro incubations of several pieces removed from the ovaries of one female.
1.1. A female-specific protein (FSP), immunologically identical to oocyte lipovitellin, is present in the hemolymph of vitellogenic female lobsters (Homarus americanus).2.2. FSP titers increase in the hemolymph during vitellogenesis, but the levels are maximum well prior to oviposition.3.3. FSP does not appear in the hemolymph during the winter months, while the ovaries are quiescent, nor does it appear in females that are in late pre-molt stages, when vitellogenesis is suppressed prior to ecdysis.4.4. It thus seems that the titer of hemolymph FSP is a good index of vitellogenesis, and that FSP is probably an extra-oocytie precursor of lipovitellin in transit to the oocyte.
1.1. The midgut gland of Limulus polyphemus contains triglycerides, phospholipids, ether-linked glycerolipids, sterol esters, and cholesterol.2.2. Lipids, principally triglycerides, accumulate during the transition from intermolt to premolt and are utilized during the molt.3.3. Limulus hemolymph contains phospholipids, cholesterol, and phthalate esters.4.4. Hyperlipidemia can be induced by subjecting Limulus to either osmotic stress or physical restraint.5.5. Neither injections of CNS homogenates nor extirpation of the posterior portion of the circumesophageal nerve ring change hemolymph lipid levels.
1.1. The subunit structure of ovoverdin, the astaxanthin-lipovitellin of lobster ovaries and eggs, isolated from Homarus gammarus (L.) is distinct from that reported in the literature for the pigment of Homarus americanus.2.2. The complex of H. gammarus has absorption maxima at ca 465 and 667 nm at 25°C and dissociates in sodium dodecylsulphate-polyacrylamide electrophoresis (SDS-PAGE) into two glycoprotein subunits of ca 140 × 103 and 105 × 103 daltons apparent molecular size.3.3. The visible absorption spectrum of the pigment alters reversibly between 5 and 25°C, for freshly prepared material, with the absorption bands bathochromically shifted at the lower temperature; the longer wavelength absorption band becomes fine structured as the temperature is lowered.4.4. A colourless lipovitellin is present in preparations of ovoverdin. The lipovitellin, only partially separated from ovoverdin in gel filtration on Agarose 6B, is resolved from the latter pigment in PAGE. It gives two glycoprotein subunits of ca 125 × 103 and 105 × 103 daltons apparent molecular size in SDS-PAGE.5.5. Precipitation of ovoverdin at low ionic strength is associated with the presence of a contaminating protein of ca 96 × 103 daltons apparent molecular size in SDS-PAGE.6.6. Storage of ovoverdin preparations at pH 7 gives rise to a red coloured product in which both subunits have been proteolytically degraded.7.7. The number of astaxanthins bound per ovoverdin molecule is discussed.
1.1. The chirality of astaxanthin from the carotenoproteins of Homarus gammarus, crustacyanin (lobster shells) and ovoverdin (lobster eggs), has been examined by the camphanate method. Crustacyanin contained , and in relative proportion 33:28:39. Astaxanthin ex ovoverdin consisted of the three optical isomers in ratio 30:28:42, closely similar to the ratio 31:25:44 found for total lobster egg astaxanthin.2.2. Individual recombination studies with apocrustacyanin and the natural astaxanthin mixture, the three pure, synthetic, optical isomers of astaxanthin and are reported. The recombined carotenoproteins were characterized by electronic and CD spectra and approximate mol. wt determined by ultrafiltration.3.3. The recombination method used resulted in carotenoproteins of α-crustacyanin size. The semisynthetic carotenoproteins obtained by recombination with each of the three astaxanthin isomers or showed only minor differences in their electronic and CD spectra relative to those of native α-crustacyanin. It is concluded that the chirality of the prosthetic group is not critical.4.4. No recombination between apo-ovoverdin and astaxanthin could be achieved. The CD properties for ovoverdin are discussed.
1.1. We have isolated two canthaxanthin-proteins from females of the anostracan, Branchinecta packardi, an orange lipovitellin from yolk platelets and a blue lipoprotein from connective tissue storage cells, where it occurs in crystalline array.2.2. Evidence based on peptide mapping and subunit size indicates that the two proteins are structurally related.3.3. Electron microscope studies suggest active biosynthesis of the blue canthaxanthin lipoprotein by connective tissue storage cells: its possible role as precursor of the oocyte lipovitellin is discussed.
1.1. Total lipid concentrations of plasma of C. gigas vary from 4.2–12.5 mg/dl dependent upon nutritional and reproductive condition. Fasting and gonadal maturity both appear to increase plasma lipid.2.2. Hemocyte total lipid in fed, reproductively mature oysters in 6.7 mg/dl.3.3. Both plasma and hemocyte lipids consist mainly of phospholipid (70–80%), with lesser amounts of the neutral lipid classes: sterol (0.5–1.2%), free fatty acids (0.8–3.8%), triglycerides (2.6–5.5%) and sterol esters (0.2–2.1%).4.4. Oyster plasma contains 20 electrophoretically resolvable proteins, including 2 lipoproteins, which were present in very low concentration.5.5. When 1-14C-palmitate is fed to oysters, the specific activities of plasma and hemocyte lipids rise over a period of 10 hr and then maintain roughly steady levels. Specific activities of hemocyte and plasma lipids were approximately equal. Free fatty acids attained the highest specific activity of any blood lipid class.6.6. By 56 hr after ingestion of 1-14C-palmitate, radioactivity was found in the several lipid classes of tissues having only blood contact with the digestive tract, thus supporting the premise of transport of lipid through the hemolymph.
1.1. A blue canthaxanthin-lipovitellin has been isolated from the yolk platelets of the eggs of the freshwater anostracan, Branchipus stagnalis (L.), and its composition and properties reported.2.2. The composition of the yolk platelets is similar to that of the brine shrimp, Artemia salina (L.).3.3. The canthaxanthin-lipovitellin and dinucleotides are specifically confined within the membrane-bound platelets.
1.1. A female-limited lipoprotein is found in the hemolymph of only those individuals with maturing oocytes. The relative concentration of the lipoprotein in the ovary increases progressively with oocyte maturation.2.2. There is no difference between the electrophoretic patterns of hemocyanin from males and females.3.3. The electrophoretic pattern of the hemocyanin components is not the same in the two morphological variants of the fiddler crab, Uca pugilator. After electrophoresis of hemolymph from the light patch variant of Uca pugilator four hemocyanin components are seen whereas only three components are seen in the hemolymph from the dark patch variant.
1.1. The total lipid, total carbohydrate, reducing sugar and d-glucose contents in whole blood and plasma of Urechis caupo were determined.2.2. The total lipid content of whole blood range from 460–1400 mg/100 ml with most of the lipid present in the cellular fraction of the blood.3.3. The whole blood contained significant amount of d-glucose and nonreducing sugar although higher concentrations of both sugars were present in the plasma.
Histological studies and immunofluorescence revealed two phases of cytoplasmic development during oogenesis of Parapenaeus longirostris. The first phase includes synthesis of a substance which accumulates later in the peripheral cortical granules. During the second phase, yolk globules appear in the cytoplasm. Immunodiffusion, Immunoelectrophoresis and immunofluorescence demonstrated materials immunologically similar to vitellin in the yolk globules of developed oocytes but not in oocytes in the first phase of development. This material appears also in the subepidermal adipose tissue and in the hemolymph, indicating the extraovarian origin of vitellin.
1.1. The circular dichroism and resonance Raman spectra of the canthaxanthin-lipovitellin of the freshwater anostracan, Branchipus stagnalis (L.), has been studied.2.2. It is concluded that the visible absorption spectrum of the lipovitellin can best be explained by a single carotenoid-binding site in which the carotenoid is bound asymmetrically in three different configurational states.
1.1. Total blood lipid of C. stelleri approximates 7 mg/dl with 4 mg/dl in the plasma. The remaining 3 mg/dl is contained in the blood cells whose count averages ca. 3000/μ1.2.2. Plasma lipids contain appreciable amounts of alkyl-diacylglycerol (5%), triglyceride (15%) and free fatty acid (7%) which can be considered as potential transport forms of acyl lipid utilized by energy metabolism. Sterols and phospholipids constitute the remainder of the plasma lipids.3.3. Plasma contains 14 electrophoretically resolvable proteins including an apparent carotenoprotein and a high molecular weight lipoprotein.4.4. Ingested 1−14C-palmitate passes into the plasma lipid compartments and into tissues without direct contact with the gastro-intestinal tract (gonad, foot, mantle). The time course of labelling and the relative specific activities of plasma and tissue lipid classes suggest that plasma FFA are the principal transport form of acyl lipid.5.5. A preliminary effort to measure the rate of turnover of plasma FFA suggests that this process may support <10% of the energy metabolism of C. stellen.
Ovarian development was induced by eyestalk ablation in the South American white shrimp, Penaeus vannamei. During the gonadotrophic cycle, ovarian protein increased from virtually undetectable levels in undeveloped ovaries to >400 mg in mature ovaries. Total protein was separated by SDS-PAGE and high molecular weight polypeptides of ~175–200 kDa were abundant in vitellogenic ovaries but absent in previtellogenic ovaries. These polypeptides are probably the yolk polypeptides.We determined in vitro protein synthesis rates for the ovary and hepatopancreas during ovarian development. Tissues from animals at the onset of vitellogenesis incorporated radiolabelled amino acids at the most active rate. Using autoradiography, we demonstrated that the ovary synthesized many polypeptides, including the major, putative yolk polypeptides. We did not detect synthesis of these polypeptides by the hepatopancreas.
Physicochemical studies have been carried out on the hemolymph and egg lipoproteins of the rock crab (Cancer antennarius). Analytical ultracentrifugal analyses of vitellogenic female HDL3 revealed the presence of two types of lipoproteins. The first with a sedimentation rate of 5.35 S was comparable to lipoproteins in male and non-vitellogenic female hemolymph. The second with a sedimentation rate of 10.74 S was comparable to the major lipoprotein of egg yolk. A similar comparison could be made following electrophoretic analyses in native polyacrylamide gels. Electrophoresis in SDS-polyacrylamide gels revealed three major apolipoproteins common to egg and vitellogenic HDL3. A fourth apolipoprotein was found in both male and female HDL3. In contrast to mammalian HDL, none of these crustacean apolipoproteins had a molecular weight less than 82000. One of these apolipoproteins appears to be comparable physicochemically to the enteric form of apolipoprotein B in mammals.
Developing ovaries of the fiddler crab, Uca pugilator, were incubated in vitro in labeled leucine, which was incorporated into the egg yolk protein, vitellin. Two primary vitellin subunits, having molecular weights of 100,600 and 123,500, were separated by SDS-polyacrylamide gel electrophoresis. These results show that the ovary of this crab has the capacity to synthesize vitellin.
Hemolymph lipoproteins in crustaceans are of the high-density type (HDL). Serum concentrations of HDL were measured monthly during 1982–1987 in crabs (Cancer antennarius) collected off the coast of Southern California. The annual profiles of concentrations feature female-specific elevations during October–December, with the peak in November being an average four-fold higher than the lows of early summer. The single departure from this pattern occurred in February–March, 1983, coinciding with a rise in water temperature due to the El Nino phenomenon. Females collected in most months were in various stages of egg maturation and brooding females also could be found at any time of year. Despite this heterogeneity, evidence supports an hypothesis that the annual increase in serum HDL occurs when most females in the population are actively vitellogenic.
Two different high density lipoproteins were isolated and characterized in the hemolymph of blue crabs (Callinectes sapidus). Lipoprotein I was found in both sexes and comprised one peptide (112,000 daltons) and lipid, primarily phosphtidyl choline. Lipoprotein I properties included a hydrated density of 1.12 g/ml, sedimentation coefficient of 5.4 Svedberg flotation units and a protein to lipid ratio of 1.0. This lipoprotein is assumed to have a role in transporting lipid from the hepatopancreas to other tissues. Lipoprotein II had three peptides (190,000, 107,000 and 78,000 daltons), phosphatidyl choline as the major lipid, a hydrated density of 1.16 g/ml, a sedimentation coefficient of 10.4 Svedberg flotation units, a protein to lipid ratio of 1.1, and a yellow to orange color due to a mixture of carotenoids. Lipoprotein II was found only in female crabs undergoing vitellogenesis. Lipoprotein II appeared after 30 days in females that had mated and completed their final molt. The maximum concentration was reached in 50 to 60 days. Lipoprotein II was not present in recently molted females in a collection of crabs from one esturine river but was present in all other stages with highest concentrations (up to 8 mg/ml hemolymph) in stages 5 and 6 (females with large, well developed ovaries). Crab ovaries had a lipoprotein similar to hemolymph Lipoprotein II. Lipoprotein II probably plays an important role in carrying lipid and specific peptides to ovarian tissues. Crustacean hemolymph lipoproteins show some similarities to insect lipophorins, but are quite different from vertebrate lipoproteins.
1. The amino acid compositions of carotenoid-containing complexes, isolated from the eggs and ovaries of three crustaceans, one lamelli-branch mollusc and one prosobranch mollusc are compared.2. The relatedness of the proteins is estimated, and possible reasons for their similarity in amino acid composition is discussed.
1.1. Concentrations on the hemolymph lipids of Cancer magister were determined. Total hemolymph lipid concentrations ranged from 14·9 to 94·0 mg% and were highest in females with developing ovaries. The phosphatides, phosphatidyl ethanolamine and phosphatidyl choline, made up 65–82 per cent of the total hemolymph lipids. The concentrations in the hemolymph of seven neutral lipid classes were measured.2.2. The fatty acid composition of the triglyceride, diglyceride, free fatty acid and phosphatide fractions of the hemolymph were analyzed.3.3. Two lipoproteins were present in the hemolymph of male and sexually immature female specimens. An additional lipoprotein appeared in the hemolymph o of females undergoing vitellogenesis.4.4. Data are provided on the lipid class composition of tissues of male and female C. magister.5.5. The labeling pattern of tissue and hemolymph lipid classes following oral administration of 1-14C-palmitate to male and female C. magister is described and discussed.
In the shrimp Penaeus semisulcatus, the digestive gland functions as the main site for the digestion, absorption and storage of nutrients and metals during the feeding stages of intermoult and for the mobilization of reserves during the non-feeding stages of pre-and post-moult. These different activities are reflected directly in the cytology of the gland. All the epithelial cells show marked fluctuations in frequency and changes in structure, form and function which occur in phase with the moult cycle. The shrimp were collected offshore from Kuwait in 1980.
The distribution of3H-leucine between the various polyopeptide components ofOrchestia gammarellus vitellogenin and lipovitellins, separated by SDS-PAGE, has been stdied after in vivo injection of this amino-acid. The results corroborate the view that, the heaviest components, or native polypeptide subunits of vitellogenin, are progressively transformed into lighter ones.
Studies with Libinia emarginata suggest that methyl farnesoate (MF), a product of the mandibular organs (MOs), may be a crustacean juvenile hormone. In order to better understand the significance of this compound in crustacean physiology, we first investigated the presence of MF in other decapods. MF was synthesized and secreted by MOs from all species tested. However, large differences in the level of MF secretion were observed between species and also between individuals of a species. For example, the level of secretion by MOs from L. emarginata was 100-fold greater than that observed in MOs from Homarus americanus. Analysis of hemolymph from these two species by GC-MS indicated comparable differences in the amount of MF present. Differences in the level of MF secretion by MOs from individuals of a species appear to reflect the physiological roles of this compound. For example, a close relationship was seen between MF secretion and gametogenesis in females of L. emarginata. Finally, treatment of lobster larvae with seawater containing MF caused a small but significant delay in their metamorphosis when compared with untreated larvae. These data suggest that MF affects reproduction in a manner similar to the effects of JH on insects, and may also have effects on the development of crustacean larvae. Taken together, these data support the classification of MF as a crustacean JH.
1.1. The relationship between the five native forms of vitellin (V1-V5) previously identified in Perinereis cultrifera oocytes was studied by following the distribution of [3H]leucine between these vitellin forms after in vivo injection of the amino acid in young and submature females.2.2. By native polyacrylamide gel electrophoresis and fluorography, the highest molecular weight form of vitellin (V1, 530,000) was first (one day incubation period) detected as being radioactive while for long incubation periods (3 to 14 days) a progressive shift in labelling was observed from V1 into the smaller forms of vitellin (V2, 500,000; V3, 470,000; V4, 430,000 and V5, 390,000).3.3. During the increasing incubation periods, a progressive shift in labelling from a single high molecular weight polypeptide (P1, 176,000) into lower molecular weight fragments characteristic of the mature vitellin form V5 was found when the vitellin fractions obtained by immunoprecipitation were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis and fluorography.4.4. These results confirm the hypothesis of a precursor-product relationship between V1 and V5 via three intermediate forms (V2 to V4) and strongly suggest that the conversion process within the oocyte involves progressive proteolytic cleavages of a single precursor component, or polypeptide subunit of V1, into those that make up V5, the mature form of vitellin.
1.1. Yolk proteins were isolated from ovaries of the shrimp Penaeus vannamei and used as an antigen for antibody production in rabbits.2.2. Protein synthesis was measured for both the hepatopancreas and the ovary in vitro, and proteins present in both tissues were immunoreactive with the antibodies.3.3. Extracts of shrimp eyestalks inhibited in vitro protein synthesis by both tissues. The inhibitory factor from the eyestalks was heat stable and had a molecular weight of 3300 daltons.
1.1. Composition of lipids and fatty acids from plasma and hemocytes separated from freshwater bivalve molluscs Diplodon delodontus were studied. In both hemolymph components phospholipids were the major lipids, but quantitative composition of phospholipids and fatty acids was different in hemocytes and plasma indicating specific functions.2.2. When molluscs were fed 14C fatty acids or 14C triacylglycerols, dietary fatty acids were principally transported by plasma and to a lesser extent by hemocytes. Labeled triacylglycerol was only found in hemocytes.3.3. When isolated blood cells were incubated with different 14C fatty acids or 14C trioleylglycerol, they fixed the majority of the label but were unable to esterify fatty acids or hydrolyze trioleylglycerol.4.4. At least five proteins were separated in plasma, the majority having a molecular weight higher than 200 × 103 daltons.5.5. Three plasma compounds with lipoprotein characteristics were recognized.
1.1. Total lipid expressed in mg/dl of whole coelomic fluid of sexually mature Strongylocentrotus purpuratus was divided between plasma, 1.05; red coelomocytes, 23.53; and white coelomocytes, 12.30.2.2. Sexually unripe animals had higher plasma lipid concentrations and lower coelomocyte packed cell volumes and total lipids.3.3. Triglycerides comprised from 25 to 50 per cent of the plasma lipids. Coelomocyte lipids consisted mainly of phospholipids and sterols.4.4. As many as twelve protein-staining bands could be resolved in serum samples by disc electrophoresis. One of the twelve bands stained with Sudan black B and may be a lipoprotein.5.5. When urchins were fed 1-14C-palmitate the labeling pattern of the acyl lipid classes of the several organs and the coelomic fluid suggested transport of lipid from the gut to other organs via the agency of the free fatty acid fraction of the coelomocyte lipids.
1.1. The lipid and fatty acid composition from the plasma and hemocytes in Octopus tehuelchus at different stages of sexual development, was determined.2.2. The highest content of lipids was found in females engaged in egg development, and the lowest in post-spawning and brooding females. Highest levels occurred during the autumn season in both sexes.3.3. Changes were mainly due to triacylglycerols and diacylglyceryl ethers.4.4. The plasma fatty acid composition did not demonstrate significant changes at different stages of maturation. The arachidonic acid (20:4 ω 6) was present at surprisingly high levels.
1.1. Starch-gel electrophoresis revealed considerable qualitative and quantitative variation in the proteins of hemolymph samples from individual adult specimens of Callinectes sapidus.2.2. Partial separation of the hemolymoh proteins was achieved by continuous-flow paper curtain electrophoresis.3.3. Two hemocyanins, fast and slow, are not interconvertible.4.4. Removal of copper from isolated hemocyanins by dialysis against cyanide-containing buffers produced apohemocyanins with electrophoretic mobilities identical to those of the intact hemocyanins.5.5. Fast hemocyanin has a copper-protein ratio of 0·2:100 and dissociates at alkaline pH.6.6. Slow hemocyanin is found almost exclusively in hemolymph from females.7.7. Another female-limited protein is found only in those specimens with maturing oocytes; this yellow, high-density lipoprotein is apparently associated with vitellogenesis.8.8. A “complex” protein, extremely variable in quantity, binds 59Fe and possesses amylase activity.9.9. A clotting protein is more abundant in serum than in plasma from the same animal.10.10. Species specificity of the electrophoretic patterns is confined to the characteristic mobility and dissociation of fast hemocyanin, the only protein found to be present in all samples of blue crab hemolymph.
1. Most of the lipids in the hemolymph of the spiny lobster, Panulirus interruptus, were associated with a high density lipoprotein (HDL3). The lipid of this lipoprotein was composed of phospholipid (88%), sterol (4%) and triglyceride (3%). 2. In animals fed 14C-labeled triglyceride radioactivity was not seen in the serum until 12 hr after feeding. Most of this serum radioactivity was associated with phosphatidyl choline. 3. Electron micrographs showed that negatively stained high density lipoproteins of the lobster had a polymorphic appearance.