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hog and NetAB mutants display nuclear positioning defects within ovaries. (A-C) Ovaries were stained with DAPI and analyzed with fluorescent microscopy to analyze nuclear position. (A) Wild type stage 10-11 eggs typically have a sharp boundary between the nurse cells and the developing oocyte (arrow). (B) hog mutants sometimes display nurse cell migration defects wherein a nurse cell lingers across this boundary (arrow). (C) NetAB mutants also display this nurse cell migration defect (arrow). (D) Mean percentage of stage 10-11 eggs that display nurse cell migration defects (*, p=0.007; **, p=0.0016; n.s. p=0.076). Hog heterozygotes fail to display nurse cell migration defects. Arcsine transformation was performed on percentage of eggs to satisfy assumptions of analysis of variance (not shown). Data shown in bar graph are means ± s.e.m. hog/wild type (n=10), hog (n=12), NetAB (n=11), hog/NetAB (n=10). doi: 10.1371/journal.pone.0072524.g003
Source publication
The netrin axon guidance genes have previously been implicated in fertility in C. elegans and in vertebrates. Here we show that adult Drosophila lacking both netrin genes, NetA and NetB, have fertility defects in both sexes together with an inability to fly and reduced viability. NetAB females produce fertilized eggs at a much lower rate than wild...
Contexts in source publication
Context 1
... stage 10 of oogenesis somatic follicle cells migrate between the oocyte and the nurse cells, in a process termed centripetal migration [39,40]. The end result is a straight boundary between the oocyte and nurse cells ( Figure 3A). Ovaries from females lacking NetAB or hog display subtle defects in the boundary with nurse cell nuclei found outside the follicle cells ( Figure 3B) or protruding through the squamous follicular cells ( Figure 3C). ...
Context 2
... end result is a straight boundary between the oocyte and nurse cells ( Figure 3A). Ovaries from females lacking NetAB or hog display subtle defects in the boundary with nurse cell nuclei found outside the follicle cells ( Figure 3B) or protruding through the squamous follicular cells ( Figure 3C). The phenotype appears to be solely due to the hog gene as NetAB mutants are statistically indistinguishable from hog mutants (p = 0.84, Figure 3C, D). ...
Context 3
... end result is a straight boundary between the oocyte and nurse cells ( Figure 3A). Ovaries from females lacking NetAB or hog display subtle defects in the boundary with nurse cell nuclei found outside the follicle cells ( Figure 3B) or protruding through the squamous follicular cells ( Figure 3C). The phenotype appears to be solely due to the hog gene as NetAB mutants are statistically indistinguishable from hog mutants (p = 0.84, Figure 3C, D). ...
Context 4
... from females lacking NetAB or hog display subtle defects in the boundary with nurse cell nuclei found outside the follicle cells ( Figure 3B) or protruding through the squamous follicular cells ( Figure 3C). The phenotype appears to be solely due to the hog gene as NetAB mutants are statistically indistinguishable from hog mutants (p = 0.84, Figure 3C, D). NetAB males of the genotype listed and the number of adult NetAB males that emerged was recorded. ...
Citations
... In D. melanogaster, netrin can affect the fertility of both females and males. Lacking the netrin gene, males significantly reduce the egg-laying capability of wild-type females, and females produce fewer fertilized eggs than wild-types [68]. In this study, eight secreted ACPs were predicted to contain signal peptides, but were not identified in mated-CB, including two spaetzles, allatostatin-CC, and cuticular protein. ...
In insects, male accessory gland proteins (ACPs) are important reproductive proteins secreted by male accessory glands (MAGs) of the internal male reproductive system. During mating, ACPs are transferred along with sperms inside female bodies and have a significant impact on the post-mating physiology changes of the females. Under sexual selection pressures, the ACPs exhibit remarkably rapid and divergent evolution and vary from species to species. The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a major insect pest of cruciferous vegetables worldwide. Mating has a profound impact on the females' behavior and physiology in this species. It is still unclear what the ACPs are in this species. In this study, two different proteomic methods were used to identify ACPs in P. xylostella. The proteins of MAGs were compared immediately before and after mating by using a tandem mass tags (TMT) quantitative proteomic analysis. The pro-teomes of copulatory bursas (CB) in mated females shortly after mating were also analyzed by the shotgun LC-MS/MS technique. In total, we identified 123 putative secreted ACPs. Comparing P. xylostella with other four insect ACPs, trypsins were the only ACPs detected in all insect species. We also identified some new insect ACPs, including proteins with chitin binding Peritrophin-A domain , PMP-22/ EMP/ MP20/ Claudin tight junction domain-containing protein, netrin-1, type II in-ositol 1,4,5-trisphosphate 5-phosphatase, two spaetzles, allatostatin-CC, and cuticular protein. This is the first time that ACPs have been identified and analyzed in P. xylostella. Our results have provided an important list of putative secreted ACPs, and have set the stage for further exploration of the functions of these putative proteins in P. xylostella reproduction.
... 94 In contrast, netrin is dispensable for cell survival, and global netrin-AB mutants have apparently wild-type egg chambers. 94,95 While this pattern of cell death does not fit the dependence receptor model, it raises the possibility that Furthermore, in vitro experiments suggest that Robo2 signaling may directly control Hes1 transcription. As Notch signaling is also integral to the proliferative dynamics of the mammary gland, 101 it will be interesting to see whether it also interacts with slit-Robo signaling in this context. ...
... Global netrin-AB mutants lay fewer eggs than control counterparts, 95 although it is unclear whether that reflects tissue-intrinsic or neuronal roles for net-A. Interestingly, netrin-independent Frazzled signaling is required cell-autonomously by germ cells later in oogenesis, 94 ...
Classical axon guidance ligands and their neuronal receptors were first identified due to their fundamental roles in regulating connectivity in the developing nervous system. Since their initial discovery, it has become clear that these signaling molecules play important roles in the development of a broad array of tissue and organ systems across phylogeny. In addition to these diverse developmental roles, there is a growing appreciation that guidance signaling pathways have important functions in adult organisms, including the regulation of tissue integrity and homeostasis. These roles in adult organisms include both tissue‐intrinsic activities of guidance molecules, as well as systemic effects on tissue maintenance and function mediated by the nervous and vascular systems. While many of these adult functions depend on mechanisms that mirror developmental activities, such as regulating adhesion and cell motility, there are also examples of adult roles that may reflect signaling activities that are distinct from known developmental mechanisms, including the contributions of guidance signaling pathways to lineage commitment in the intestinal epithelium and bone remodeling in vertebrates. In this review, we highlight studies of guidance receptors and their ligands in adult tissues outside of the nervous system, focusing on in vivo experimental contexts. Together, these studies lay the groundwork for future investigation into the conserved and tissue‐specific mechanisms of guidance receptor signaling in adult tissues.
Key Points
Axon guidance ligand and receptor expression often persist into adulthood in neuronal and non‐neuronal tissues alike.
Recent work in genetic model organisms highlights the diverse roles of guidance factors in adult tissues.
Guidance factors are required intrinsically in a variety of adult tissues but can also regulate tissue function indirectly via functions in the nervous and vascular systems.
Studies outside of the nervous system are likely to enhance our understanding of these diverse siganling molecules and could suggest novel signaling modalities in the nervous system.
... Netrin and its receptors may also play a role in reproduction. In Drosophila, netrinAB mutant females have decreased fertility (Newquist et al., 2013), although it is unclear whether this reflects tissue-intrinsic or neuronal requirements. Although the nervous system profoundly influences organismal physiology, including reproduction (Drummond-Barbosa, 2019), Netrin also affects cell migration and adhesion by acting on its receptors in other tissues. ...
... To determine whether Fra function in the ovary is dependent on Netrin, we tested whether Netrin is required in the ovary. Female flies homozygous for a small deletion removing both netrinA and netrinB (netrinAB ΔGN ; Brankatschk and Dickson, 2006;Newquist et al., 2013) survive to adulthood at low frequency, and we used these 'escapers' to examine the effect of global Netrin removal on oogenesis. A previous study found that netrinAB ΔGN escaper females lay fewer eggs than control flies; however, no defects were observed in ovary morphology (Newquist et al., 2013). ...
... Female flies homozygous for a small deletion removing both netrinA and netrinB (netrinAB ΔGN ; Brankatschk and Dickson, 2006;Newquist et al., 2013) survive to adulthood at low frequency, and we used these 'escapers' to examine the effect of global Netrin removal on oogenesis. A previous study found that netrinAB ΔGN escaper females lay fewer eggs than control flies; however, no defects were observed in ovary morphology (Newquist et al., 2013). Consistent with these results, ovarioles from netrinAB ΔGN escapers appear morphologically indistinguishable from control ovarioles (Fig. 6C). ...
The Netrin receptor Frazzled/Dcc (Fra in Drosophila) functions in diverse tissue contexts to regulate cell migration, axon guidance and cell survival. Fra signals in response to Netrin to regulate the cytoskeleton and also acts independently of Netrin to directly regulate transcription during axon guidance in Drosophila. In other contexts, Dcc acts as a tumor suppressor by directly promoting apoptosis. In this study, we report that Fra is required in the Drosophila female germline for the progression of egg chambers through mid-oogenesis. Loss of Fra in the germline, but not the somatic cells of the ovary, results in the degeneration of egg chambers. Although a failure in nutrient sensing and disruptions in egg chamber polarity can result in degeneration at mid-oogenesis, these factors do not appear to be affected in fra germline mutants. However, similar to the degeneration that occurs in those contexts, the cell death effector Dcp-1 is activated in fra germline mutants. The function of Fra in the female germline is independent of Netrin and requires the transcriptional activation domain of Fra. In contrast to the role of Dcc in promoting cell death, our observations reveal a role for Fra in regulating germline survival by inhibiting apoptosis.
... In a previous study, genes associated with netrin axon guidance were proved to be implicated in fertility in C. elegans and chick (Murakami et al., 2010;Lai Wing Sun et al., 2011). In Drosophila, the knockout of netrin gene affects fertility in females (Newquist et al., 2013). Netrin proteins may be involved in the development of sex hormone-targeting organ tumors (Hao et al., 2020). ...
The molecular mechanisms underlying the transition from primary to secondary growth stage of oocyte remain elusive in teleost. In this study, oocytes in various diameters and developmental states, including primary growth stage (PG) (~35 μm), early lipid droplet stage (EDO) (~70 μm) and late lipid droplet stage (LDO) (~100 μm) in P. olivaceus, were isolated using collagenase digestion combined with physical filtering methods in vitro. Subsequent transcriptome analysis showed that there were 2288, 3344, and 337 differentially expressed genes (DEGs) in comparison of PG-vs-EDO, PG-vs-LDO and EDO-vs-LDO, respectively. Most of the DEGs, such as members of the ZP family and the HSP family, were highly expressed at PG. Besides, some genes associated with fatty acid metabolism were up-regulated from PG to LDO. KEGG pathway analysis revealed that some DEGs were linked to Notch, Hippo, Axon guidance, and immune-related pathways including the TNF and Small cell lung cancer signaling pathway. In addition, we used the up-regulated gene set in the trend analysis to enrich for a number of signaling pathways related to the lipoprotein synthesis, including fatty acid biosynthesis, glycerolipid metabolism, glycerophospholipid metabolism, and phospholipase D signaling pathways. This study broadened our understanding of the genes and signaling pathways involved in the transition from primary to secondary oocyte growth stage, and provided some clues in regard to the mechanisms underlying lipid droplet synthesis in oocyte of teleost species.
... The ability to fly was tested using a dropping assay described by Newquist et al. (2013). Three males were dropped at the same time from one vial onto the lab bench. ...
Holometabolic organisms undergo extensive remodelling of their neuromuscular system during metamorphosis. Relatively, little is known whether or not the embryonic guidance of molecules and axonal growth mechanisms are re-activated for the innervation of a very different set of adult muscles. Here, we show that the axonal attractant Sidestep (Side) is re-expressed during Drosophila metamorphosis and is indispensable for neuromuscular wiring. Mutations in side cause severe innervation defects in all legs. Neuromuscular junctions (NMJs) show a reduced density or are completely absent at multi-fibre muscles. Misinnervation strongly impedes, but does not completely abolish motor behaviours, including walking, flying, or grooming. Overexpression of Side in developing muscles induces similar innervation defects; for example, at indirect flight muscles, it causes flightlessness. Since muscle-specific overexpression of Side is unlikely to affect the central circuits, the resulting phenotypes seem to correlate with faulty muscle wiring. We further show that mutations in beaten path Ia (beat), a receptor for Side, results in similar weaker adult innervation and locomotion phenotypes, indicating that embryonic guidance pathways seem to be reactivated during metamorphosis.
... Still, in many of these contexts the molecular mechanisms underlying the functions of these proteins are unclear. In addition, in some cases axon guidance molecules appear to act in the nervous system to impact the function of other tissues (Trent et al., 1983;Asakura et al., 2007;Ziel et al., 2009;Newquist et al., 2013) ...
... Netrin is also required for egg-laying in Drosophila (Newquist et al., 2013). While control flies laid almost 50 eggs per day, global netAB mutant flies laid an average of 9 eggs per day (Newquist et al., 2013). ...
... Netrin is also required for egg-laying in Drosophila (Newquist et al., 2013). While control flies laid almost 50 eggs per day, global netAB mutant flies laid an average of 9 eggs per day (Newquist et al., 2013). It is unclear why netAB mutants have a decrease in egg-laying, and the hatch rate of the eggs laid was similar to control flies (Newquist et al., 2013). ...
Frazzled (Fra) is a highly conserved receptor expressed on the cell membrane, and it is important for several morphological processes, including cell migration, axon guidance, and adhesion. In addition to these functions, the vertebrate homologue of Fra, Dcc, also functions as a tumor suppressor that has a pro-apoptotic effect in the absence of its canonical ligand Netrin. In both invertebrates and vertebrates, the axon guidance cue Netrin interacts with the extracellular domain of Fra/Dcc to recruit cytoplasmic proteins and affect local cytoskeletal changes to promote axon growth across the midline. In addition, Fra functions independently of Netrin as a transcription factor. Fra is cleaved by gamma-secretase, which allows the Fra intracellular domain to enter the nucleus and activate transcription. Fra activates transcription of Commissureless, and endosome cycling receptor that is required to promote axon growth across the midline. However, whether this signaling mode of Fra is required in other tissue contexts outside of the nervous system is unknown. In Chapter 1, I introduce a subset of axon guidance genes and how they regulate gene expression in the nervous system as well as their known roles in reproductive tissues. In Chapter 2, I show that Fra is required in the fly ovary for egg chambers to progress through mid-oogenesis independently of Netrin, and this requires the transcriptional activation domain within the Fra intracellular domain. Interestingly, in contrast to the pro-apoptotic role that Dcc has in vertebrates, Fra has an anti-apoptotic role in the germline. In Chapter 3, I use a yeast-two hybrid screen to identify proteins that interact with the Fra intracellular domain, and test the DNA-binding proteins identified for a role in axon guidance and in the female germline. Finally, in Chapter 4 I discuss the implications of this work and potential future directions that would be exciting to explore.
... Netrin is a diffusible laminin-like protein and conserved from worms to mammals. In Drosophila, the NetAB mutants exhibit egg-laying defects due to ovulation defects in females [79]. The clathrin heavy chain gene, FRP gene (three copies) and NetAB genes could be found in the N. cucumeris genome (Additional file 1: Table S14), indicating that they perhaps function similarly in the regulation of oviposition in N. cucumeris. ...
Background:
Predatory mites (Acari: Phytoseiidae) are the most important beneficial arthropods used in augmentative biological pest control of protected crops around the world. However, the genomes of mites are far less well understood than those of insects and the evolutionary relationships among mite and other chelicerate orders are contested, with the enigmatic origin of mites at one of the centres in discussion of the evolution of Arachnida.
Results:
We here report the 173 Mb nuclear genome (from 51.75 Gb pairs of Illumina reads) of the predatory mite, Neoseiulus cucumeris, a biocontrol agent against pests such as mites and thrips worldwide. We identified nearly 20.6 Mb (~ 11.93% of this genome) of repetitive sequences and annotated 18,735 protein-coding genes (a typical gene 2888 bp in size); the total length of protein-coding genes was about 50.55 Mb (29.2% of this assembly). About 37% (6981) of the genes are unique to N. cucumeris based on comparison with other arachnid genomes. Our phylogenomic analysis supported the monophyly of Acari, therefore rejecting the biphyletic origin of mites advocated by other studies based on limited gene fragments or few taxa in recent years. Our transcriptomic analyses of different life stages of N. cucumeris provide new insights into genes involved in its development. Putative genes involved in vitellogenesis, regulation of oviposition, sex determination, development of legs, signal perception, detoxification and stress-resistance, and innate immune systems are identified.
Conclusions:
Our genomics and developmental transcriptomics analyses of N. cucumeris provide invaluable resources for further research on the development, reproduction, and fitness of this economically important mite in particular and Arachnida in general.
... gcm-Gal4,tub-Gal80 ts (Soustelle et al., 2007). Garbe et al., 2007); gcm rA87 (Vincent et al., 1996); gcm N7-4 (Vincent et al., 1996); UAS-gcm (F18A) (Bernardoni et al., 1998); UAS-gcm-RNAi; gcm>GFP/gcm>GFP (used as a homozygous mutant of gcm) (Popkova et al., 2012); UAS-string (Inaba et al., 2011); UAS-dacapo (Lane et al., 1996); gcm 34 (Vincent et al., 1996); (Newquist et al., 2013a(Newquist et al., , 2013b; unc5 8 (Labrador et al., 2005); collagen-Gal4 (Asha et al., 2003); engrailed-Gal4 driver (Hidalgo, 1994;Lawrence and Morata, 1976); GMR 29F05-Gal4 (Pfeiffer et al., 2008); UAS-unc5-RNAi; UAS-unc5 (von Hilchen et al., 2010); nsyb-Gal4>GFP-LAMP (B# 42714); elav-Gal4. The RNAi lines were obtained from Bloomington and/or the VDRC stock center. ...
... NetA D(von Hilchen et al., 2010;Newquist et al., 2013aNewquist et al., , 2013b; NetB D(von Hilchen et al., 2010;Newquist et al., 2013aNewquist et al., , 2013b; NetA D NetB TM(Brankatschk and Dickson, 2006); NetA D NetB mycBrankatschk and Dickson, 2006) (note that both NetA D NetB TM and NetA D NetB myc encode the c-myc epitope tags); UAS-NetB-RNAi(Manhire-Heath et al., 2013); UAS-NetB(Timofeev et al., 2012); NP4151-Gal4 and NP4012-Gal4 (DGRC, Kyoto)(Timofeev et al., 2012;Hayashi et al., 2002); UAS-NetA-RNAi(Manhire- Heath et al., 2013); UAS-NetA ...
... NetA D(von Hilchen et al., 2010;Newquist et al., 2013aNewquist et al., , 2013b; NetB D(von Hilchen et al., 2010;Newquist et al., 2013aNewquist et al., , 2013b; NetA D NetB TM(Brankatschk and Dickson, 2006); NetA D NetB mycBrankatschk and Dickson, 2006) (note that both NetA D NetB TM and NetA D NetB myc encode the c-myc epitope tags); UAS-NetB-RNAi(Manhire-Heath et al., 2013); UAS-NetB(Timofeev et al., 2012); NP4151-Gal4 and NP4012-Gal4 (DGRC, Kyoto)(Timofeev et al., 2012;Hayashi et al., 2002); UAS-NetA-RNAi(Manhire- Heath et al., 2013); UAS-NetA ...
Collective migration is a complex process that contributes to build precise tissue and organ architecture. Several molecules implicated in cell interactions also control collective migration, but their precise role and the finely tuned expression that orchestrates this complex developmental process are poorly understood. Here, we show that the timely and threshold expression of the Netrin receptor Frazzled triggers the initiation of glia migration in the developing Drosophila wing. Frazzled expression is induced by the transcription factor Glide/Gcm in a dose-dependent manner. Thus, the glial determinant also regulates the efficiency of collective migration. NetrinB but not NetrinA serves as a chemoattractant and Unc5 contributes as a repellant Netrin receptor for glia migration. Our model includes strict spatial localization of a ligand, a cell autonomously acting receptor and a fate determinant that act coordinately to direct glia toward their final destination.
Artificial insemination (AI) has been used as a routine technology globally in the pig production industry since 1930. One of the preferable advantages of AI technology is that the semen of elite boars can be disseminated to the commercial sow population rapidly. Understanding the genetic background of semen traits may help in developing genetic improvement programs of boars by including these traits into the selection index. In this study, we utilized weighted single-step genome-wide association study (wssGWAS) to identify genetic regions and further candidate genes associated with sperm morphology abnormalities (proximal droplet, distal droplet, bent tail, coiled tail, and distal midpiece reflex) in a Duroc boar population.
Several genomic regions explained 2.76%–9.22% of the genetic variances for sperm morphology abnormalities were identified. The first three detected QTL regions together explained about 7.65%–25.10% of the total genetic variances of the studied traits. Several genes were detected and considered as candidate genes for each of the traits under study: coiled tail, HOOK1, ARSA, SYCE3, SOD3, GMNN, RBPJ, STIL, and FGF1; bent tail, FGF1, ADIPOR1, ARPC5, FGFR3, PANX1, IZUMO1R, ANKRD49, and GAL; proximal droplet, NSF, WNT3, WNT9B, LYZL6, FGFR1OP, RNASET2, FYN, LRRC6, EPC1, DICER1, FNDC3A, and PFN1; distal droplet, ARSA, SYCE3, MOV10L1, CBR1, KDM6B, TP53, PTBP2, UBR7, KIF18A, ADAM15, FAAH, TEKT3, and SRD5A1; and distal midpiece reflex, OMA1, PFN1, PELP1, BMP2, GPR18, TM9SF2, and SPIN1. GO and KEGG enrichment analysis revealed the potential function of the identified candidate genes in spermatogenesis, testis functioning, and boar spermatozoa plasma membrane activating and maintenance.
In conclusion, we detected candidate genes associated with the coiled tail, bent tail, proximal droplet, distal droplet, and distal midpiece reflex in a Duroc boar population using wssGWAS. Overall, these novel results reflect the polygenic genetic architecture of the studied sperm morphology abnormality traits, which may provide knowledge for conducting genomic selection on these traits. The detected genetic regions can be used in developing trait-specific marker assisted selection models by assigning higher genetic variances to these regions.
Siren molecule calls loudly to mosquitoes
People infected by malaria become more attractive to the mosquito vectors of the disease, which facilitates the spread of malaria. Emami et al. found that red blood cells of the host respond to a parasite-derived isoprenoid called HMBPP by increasing the production of carbon dioxide and several monoterpenes and aldehydes. Mosquitoes fed HMBPP-spiked blood displayed malaria parasite–specific changes in gene transcription, which reinforced attractiveness for the mosquito. HMBPP also stimulates mosquito feeding and malaria parasite reproduction. Thus, the parasite manipulates its mammalian host to make it more attractive to the insect vectors and exploits the same molecule to amplify transmission.
Science , this issue p. 1076
