Figure - available from: Frontiers in Marine Science
This content is subject to copyright.
Transmission electron micrographs of the fresh spermatozoon in sterlet. (A) Longitudinal sagittal section of the spermatozoon showing different parts of the cell; (B) higher magnification longitudinal section of the truncate of spermatozoon exhibiting acrosome (A), endonuclear canals (ENC), nucleus (N), and posterolateral projections (PLP); (C) ultrastructure of the midpiece showing nuclear membrane (NM), flagellum (F) separated by cytoplasmic channel (CC), mitochondrion (M), distal centriole (DC), proximal centriole (PC), and implantation fossa (IF); (D) higher magnification of spermatozoon midpiece region displaying various normal and unchanged sections of the spermatozoon; (E) higher magnification of spermatozoon flagellum showing cytoplasmic canal without abnormality in the plasma membrane (PM).
Source publication
The present study aimed to evaluate cryo-injury during the cryopreservation process in sterlet (Acipenser ruthenus) sperm, focusing on ultrastructural characteristics. Post-thaw sperm quality parameters, including total motility rate, curvilinear velocity (VCL), linearity (LIN), plasma membrane integrity, antioxidant status, DNA damage, and fine ul...
Similar publications
Computer-aided analysis of biological microscopy data has seen a massive improvement with the utilization of general-purpose deep learning techniques. Yet, in microscopy studies of multi-organism systems, the problem of collision and overlap remains challenging. This is particularly true for systems composed of slender bodies such as swimming nemat...
The flagellar movement of the mammalian sperm is essential for male fertility as it enables this cell to reach and fertilize an egg. In the female reproductive tract, human spermatozoa undergo a process called capacitation which promotes changes in their motility. Only those spermatozoa that change to hyperactivated (HA) motility are capable of fer...
Sperm modulate their flagellar symmetry to navigate through complex physico-chemical environments and achieve reproductive function. Yet it remains elusive how sperm swim forwards despite the inherent asymmetry of several components that constitutes the flagellar engine. Despite the critical importance of symmetry, or the lack of it, on sperm navig...
Citations
... Semen processing, particularly semen dilution, handling, and deep-freezing, reduces natural antioxidants in sperm making them vulnerable to the ROS and weakening acrosome and plasma membranes, DNA integrity, and viability of spermatozoa [42]. A functional membrane plays an important role in sperm motility, and many other physiological events, such as acrosome reaction, capacitation, and fertilization [43]. The plasma membranes of the head and midpiece are more sensitive against oxidative damage because significant distortion was found in these areas after cryopreservation of bull spermatozoa [44]. ...
Aim
The aim of this study is the evaluation effect of nanoliposome-loaded Mito-Tempo on sperm parameters during human sperm cryopreservation.
Methods
Semen samples of 50 Asthenoteratozoospermia men (random) were collected. Sperm parameters were analyzed based on World Health Organization (WHO, 2010) criteria (2021) and each sample was divided into 5 groups (E1–E5). E1 (control group): the sperm was cryopreserved without nanoliposome, and Mito-Tempo. E2: sperm cryopreservation with Mito-Tempo-loaded nanoliposome (Mito-Tempo 0.1 mM) + freezing medium. E3: sperm cryopreservation with Mito-Tempo-loaded nanoliposome (Mito-Tempo 0.2 mM) + freezing medium. E4: in this group, the cryopreservation sperm with Mito-Tempo 0.3 mM + freezing medium. E5: the cryopreservation sperm with Mito-Tempo 0.2 mM + freezing medium.
Results
The result of this study indicated that sperm parameters and total antioxidant capacity (TAC) significantly increase in E3 and E4 groups, compared to E1, E2, and E5 groups respectively (P < 0.05). The percentage of abnormal morphology, DNA fragmentation index (DFI), malondialdehyde (MDA), and the levels of ROS significantly decrease in E3 and E4 groups, compared to E1, E2, and E5 groups (P < 0.05). In addition, the sperm parameters and stress oxidative factors significantly improve in E3 group compared to other groups (P < 0.05).
Conclusions
In conclusion, the combination of Mito-Tempo with nanoliposome due to its ability to cooperate with lipid layers may lead to significant performance in reducing oxidative stress damage and increasing the quality of sperm parameters.
... As mentioned above, despite the availability of various optimized protocols for cryopreservation of sturgeon spermatozoa, quality of sturgeon sperm, as well as of most fish species, declines significantly during the freeze-thaw process, affecting fertilization and hatching rates. Several studies related to the cryo-injury of sturgeon sperm during the cryopreservation process, have been reported focusing on various sperm quality parameters, such as sperm motility and fertilization ability, plasma membrane integrity, the level of LPO and carbonyl derivatives of proteins (CP), antioxidant status, DNA damage, morphology and fine ultrastructure [7,31,45,47,169,178,192]. Molecular and subcellular cryo-injury of frozen/thawed fish spermatozoa was reviewed by [188]. ...
... Also, it has been established that products of LPO exhibit genotoxicity and mutagenicity and may affect mature spermatozoa [8]. Accumulation of the LPO carbonyl by-products, which react with thiobarbituric acid (TBARS) is a key sign of LPO intensification and is widely used as an oxidative stress indicator during cryopreservation [17,18,[21][22][23]47,87,99,141,142,150,169,171]. As shown by Shaliutina et al. [169], the loss of motility and speed of Russian and Siberian sturgeon spermatozoa, as well as the loss of DNA integrity during short-term storage in vitro, may be associated with oxidative stress, since it is accompanied by the accumulation of TBARS and CP in spermatozoa, which significantly impair the cellular metabolism of spermatozoa, which leads to subsequent decrease in motility indicators. ...
... On the other hand, in a study by Shaliutina- [47] no significant changes in the level of TBARS, CAT and SOD activity in spermatozoa and seminal fluid of sterlet were observed after freezing. These differences between studies of the effect of cryopreservation on the antioxidant status of sturgeon sperm may be due to differences in freezing procedures or may be due to the use of different cryoprotectants. ...
... Sperm cryopreservation is a safe method for storing and preserving genetic material [5,6] and a conservation strategy for biodiversity programs for threatened or endangered species [7,8]. Moreover, it is a powerful approach in fish hatchery because it is a useful technique for effective and easy broodstock management and artificial fertilization [9]. ...
... No reports are available in the literature on cryodamage to S. cuspicaudus sperm during cryopreservation. Therefore, this study aimed to evaluate the injuries suffered by S. cuspicaudus spermatozoa at the DNA, mitochondria, and plasma membrane through the cryopreservation process (prefrozen semen and thawed semen) using EG as a cryoprotectant agent to different inclusion percentages (6,8, and 10%). ...
... Ethylene glycol (EG) (Sigma, St. Louis, MO, USA) was used as a cryoprotectant agent (CPA) at three inclusion percentages (6,8, and 10%) combined with 6% glucose and 5% skim milk powder. The semen was diluted at a ratio of 1:4 (semen: extender, 27 ± 1 • C). ...
The study aimed to evaluate cryo-injury during the cryopreservation in Sorubim cuspicaudus sperm with ethylene glycol (EG) at different rates (6, 8, 10%). Fresh, prefrozen, and post-thawed sperm quality as motility total, velocities, mitochondria damage (Mit-d), membrane damage (Mem-d), and DNA fragmentation (DNA-f), were examined. The Mit-d, Mem-d, and DNA-f were evaluated through flow cytometry. High motility (>95%) and a low percentage of Mem-d (1.0 ± 0.5%), Mit-d (1.4 ± 0.9%), and DNA-f (2.4 ± 0.8%) were recorded for fresh semen. Prefrozen semen increases in Mit-d and DNA-f were observed compared to fresh semen (p < 0.05). In thawed semen, increased Mit-d (2.6 to 3-fold), Mem-d (6 to 1-fold), and DNA-f (3.3 to 6.6-fold) compared to prefrozen was observed. Thawed semen showed Mit-d (34 to 37-fold), Mem-d (24.5 to 26.6-fold) and DNA-f (13 to 18.5-fold) increased high. In conclusion, the present study demonstrated that mitochondria, membrane, and DNA integrity undergo significant damage during both pre-freezing and freezing/thawing with EG inclusion percentages from 6 to 10% that affect its fertilizing capacity, which is reduced to half of that obtained with fresh semen. It is suggested that a cryoprotective solution composed of 6% EG, 6% glucose, and 5% skimmed milk powder is a useful protocol for the cryopreservation of S. cuspicaudus semen.
... And also the results showed that in partial changes in the ultrastructural compartments, weakening of the midpiece and rupture of the plasma membrane of the flagellum were seen. The author believes that this damage is not due to oxidative stress that can occur in cryopreserved sperm; expressed that there is physical damage that occurs during the formation of ice crystals during freezing process [51]. ...
In this section, cryopreservation of fish genetic resources, which is one of the important applications to ensure the sustainability of genetic resources of freshwater fish species, is discussed. At the same time, information is provided about the possible sources of contamination that may be encountered during cryopreservation applications. In this context, the results of sperm, egg, and embryo cryopreservation studies of fish and their success and failure in applications were evaluated in addition to the process from past to present. Information is given about the contamination that may develop depending on the applications in the process of cryopreservation and dissolving processes, as well as the studies carried out to eliminate extracellular disease agents. In the section, in addition to the evaluation of the results of scientific studies, commercial companies that commercially carry out gamete cryopreservation applications are also included. The contamination that may develop depending on the applications in the process of cryopreservation and thawing processes, as well as the studies carried out to eliminate extracellular disease agents are mentioned.
Schizothorax plagiostomus commonly known as snow-trout, is a popular game-food fish, found in the cold waters of the rivers, streams, tributaries and lakes of the Hindukush- Karakoram- Himalayan mountains/ foothills even at the elevation of 1180–3000 m above from the sea level and is considered to the be major source of animal protein. In recent past, there has been a severe decline in Schizothoracine population due to uncontrolled anthropogenic activities and climate change. Therefore, there is an urgent need for critical analysis of annual gonadal development in Schizothorax species. In this study, the seasonal variations of testicular architecture and development were examined in adult S. plagiostomus at Garhwal Himalaya, Uttarakhand, India. Testicular-somatic index were found to be ranged from 0.254 ± 0.06–7.104 ± 1.62 with maximal value recorded in September-October and minimal in April-May. Testicular histology revealed abundance of undifferentiated spermatogonia, meiotic spermatid and spermatozoa in pre-spawning and spawning capable phases respectively. The ultra-structure of spermatozoa showed 1.78 ± 0.27 µm long ovoid shaped head without any acrosome, 0.35 ± 0.05 µm long ellipsoidal mid-piece and 22.5 ± 0.65 µm long flagella. We further have evaluated the milt/semen volume, estimated the sperm density and motility in male brooders. Notably the spermatogenic capacity was found to be consistent in two breeding seasons e.g. spawning capable (September-October) and residual spawning (February-March) phases. In summary, this is the first comprehensive qualitative and quantitative report of the seasonal variations of the spermatogenic output in adult male S. plagiostomus. This data may provide valuable information for the conservation management and artificial breeding program of S. plagiostomus.
