• Fisheries and Aquatic Sciences
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• 제24권2호
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• pp.63-77
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• 2021

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein's solution, Hank's balanced salt solution, marine fish Ringer's solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below -10℃/min. The thawing temperature of 45℃ was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p < 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.

• 한국동물생명공학회지
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• 제37권2호
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• pp.130-135
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• 2022

Epididymal sperm cryopreservation provides a potential method for preserving genetic material from males of endangered species. This pilot study was conducted to develop a freezing method for tiger epididymal sperm. We evaluated post-thaw sperm condition using testes with intact epididymides obtained from a Siberian tiger (Panthera tigris altaica) after castration. The epididymis was chopped in Tyrode's albumin-lactate-pyruvate 1x and incubated at 5% CO₂, 95% air for 10 min. The Percoll separation density gradient method was used for selective recovery of motile spermatozoa after sperm collection using a cell strainer. The spermatozoa were diluted with modified Norwegian extender supplemented with 20 mM trehalose (extender 1) and subsequent extender 2 (extender 1 with 10% glycerol) and frozen using LN₂ vapor. After thawing at 37℃ for 25 s, Isolate^® solution was used for more effective recovery of live sperm. Sperm motility (computerized assisted sperm analysis, CASA), viability (SYBR-14 and Propidium Iodide) and acrosome integrity (Pisum sativum agglutinin with FITC) were evaluated. The motility of tiger epididymal spermatozoa was 40.1 ± 2.0%, and progressively motile sperm comprised 32.7 ± 2.3%. Viability was 56.3 ± 1.6% and acrosome integrity was 62.3 ± 4.4%. Cryopreservation of tiger epididymal sperm using a modified Norwegian extender and density gradient method could be effective to obtain functional spermatozoa for future assisted reproductive practices in endangered species.

• Animal Bioscience
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• 제35권9호
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• pp.1351-1359
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• 2022

Objective: The objective of this study was to analyse the differentially abundant proteins caused by freeze-thawing of ram sperm and explore candidate proteins of interest for their ability to improve ram sperm cryopreservation outcomes in vitro. Methods: Sperm were from three mature Dorper. Fresh and frozen sperm proteins were extracted, and the differentially abundant proteins were analysed by mass spectrometry. Among these proteins, lactoferrin (LTF) was selected to be added before cryopreservation. Next, sperm samples were diluted in Tris extender, with the addition of 0, 10, 100, 500, and 1,000 ㎍/mL of LTF. After thawing, sperm quality was evaluated by motility, plasma membrane integrity, mitochondrial activity and reactive oxygen species (ROS). Results: Cryopreservation significantly altered the abundance of 40 proteins; the abundance of 16 proteins was increased, while that of 24 proteins was decreased. Next, LTF was added to Tris extender applied to ram sperm. The results showed that sperm motility and plasma membrane integrity were significantly improved (p<0.05) by supplementation with 10 ㎍/mL LTF compared to those in the control group. There was no significant difference in mitochondrial activity between the 0 ㎍/mL group and other groups (p>0.05). Supplementation of the cryoprotective extender with 10 ㎍/mL LTF led to decreased ROS levels compared with those in the control and other groups (p<0.05). Conclusion: The LTF is an important protein during cryopreservation, and the addition of 10 ㎍/mL LTF to a cryoprotective extender can significantly improve the function of frozen ram sperm.

• Animal Bioscience
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• 제36권12호
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• pp.1821-1830
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• 2023

Objective: This study investigated the effect of adding seminal plasma to frozen-thawed semen on the quality of sperm and pregnancy following insemination in dromedary camels. Methods: In experiment 1, the frozen-thawed semen from 9 collections (3 bulls) was further diluted with either the base extender or homologous seminal plasma (HSP). In the second experiment, a pooled sample of frozen-thawed semen was diluted with either seminal plasma from another three bulls. Live percentage, total and progressive motility, functional and acrosome integrity, and sperm kinematics were evaluated at 15, 60, and 120 minutes post-thawing and compared to the non-treated control. In experiment 3, frozen semen was used to inseminate camels in the following experimental groups: 1-Single insemination with double dose undiluted frozen semen (n = 9); 2-Re-insemination in 6 hours with undiluted semen (n = 13); 3-Single insemination with HSP treated sperm (n = 14). Results: Frozen-thawed sperm diluted in HSP or the non-homologous seminal plasma from Bull C indicated an improvement in all parameters after 1 hour post-thawing incubation (p<0.05). The proportion of total and progressively motile sperm did not drop significantly at 60 minutes post-thawing when diluted with the seminal plasma of Bull C (p>0.05). Double insemination with nontreated sperm and single insemination with HSP-treated sperm resulted in similar pregnancy rates (15.3% vs 21.4%, p>0.05). None of the camels conceived with double-dose single insemination of nontreated sperm. Conclusion: Seminal plasma improves sperm longevity and motility after thawing in dromedary camel with a significant between-bull variation in effect. Low post-thaw sperm longevity might be the cause behind the low pregnancy rates in frozen semen insemination of dromedary camels.

• Animal Bioscience
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• 제37권4호
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• pp.631-639
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• 2024

Objective: This study evaluates goat sperm motility in response to metabolic substrates and various inhibitors, aiming to assess the relative contribution of glycolysis and mitochondrial oxidation for sperm movement and adenosine triphosphate (ATP) production. Methods: In the present study, two main metabolic substrates; 0 to 0.5 mM glucose and 0 to 30 mM pyruvate were used to evaluate their contribution to sperm movements of goats. Using a 3-chloro-1,2-propanediol (3-MCPD), a specific inhibitor for glycolysis, and carbonyl cyanide 3-chlorophenylhydrazone as an inhibitor for oxidative phosphorylation, cellular mechanisms into ATP-generating pathways in relation to sperm movements and ATP production were observed. Data were analysed using one-way analysis of variance for multiple comparisons. Results: Sperm motility analysis showed that either glucose or pyruvate supported sperm movement during 0 to 30 min incubation. However, the supporting effects were abolished by the addition of a glycolysis inhibitor or mitochondrial uncoupler, concomitant with a significant decrease in ATP production. Although oxidative phosphorylation produces larger ATP concentrations than those from glycolysis, sperm progressivity in relation to these two metabolic pathways is comparable. Conclusion: Based on the present study, we suggest that goat sperm use glucose and pyruvate to generate cellular energy through glycolysis and mitochondrial respiration pathways to maintain sperm movement.

• Animal Bioscience
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• 제37권5호
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• pp.852-861
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• 2024

Objective: The present study aimed to investigate the effect of β-nicotinamide mononucleotide (NMN) supplementation on ram sperm quality during storage at 4℃ in vitro. Methods: Tris-citric acid-glucose solution containing different doses of NMN (0, 30, 60, 90, and 120 µM) was used to dilute semen collected from rams and it was stored at 4℃. Sperm motility, plasma membrane integrity as well as acrosome integrity were evaluated at 0, 24, and 48 h time points after storage at 4℃. In addition, sperm mitochondrial activity, lipid peroxidation (LPO), malondialdehyde (MDA) content, reactive oxygen species (ROS) content, glutathione (GSH) content, superoxide dismutase (SOD) activity, and apoptosis were measured at 48 h time point after storage at 4℃. Results: Results demonstrate that the values obtained for sperm motility, acrosome integrity, and plasma membrane integrity in the NMN treatments were significantly higher than control (p<0.05). The addition of 60 µM NMN significantly improved ram sperm mitochondrial activity and reduced LPO, MDA content, and ROS content compared to control (p<0.05). Interestingly, sperm GSH content and SOD activity for the 60 µM NMN treatment were much higher than those observed for control. NMN treatment also decreased the level of Cleaved-Caspase 3, Cleaved-Caspase 9, and Bax while increasing Bcl-2 level in sperm at 48 h time point after storage at 4℃. Conclusion: Ram sperm quality can be maintained during storage at 4℃ with the addition of NMN at 60 µM to the semen extender. NMN also reduces oxidative stress and apoptosis. Overall, these findings suggest that NMN is efficient in improving the viability of ram sperm during storage at 4℃ in vitro.

• Toxicological Research
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• 제21권2호
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• pp.129-134
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• 2005

Styrene is a commercially important chemical used mainly in the production of plastics. A toxic effect exerted by styrene exposure may cause infertility, congenital anomalies or death in offspring. Treatment with styrene for 0, 50, 100, and 500 mg/kg for 5 days in Sprague-Dawley rats significantly decreased sperm motilities and sperm counts while sperm abnormalities were significantly increased. To determine the relationship between changes in sperm motilities and roles of reactive oxygen species (ROS), we determined the effect of styrene on ROS production and mRNA expression of antioxidant enzymes in rats. ROS production was enhanced by styrene treatment in a dose-dependent manner. The mRNA expression of catalase and superoxide dismutase (SOD) 2 was strongly suppressed by styrene treatment although SOD1 or glutathione peroxidase (GPX) 4 expressions were not significantly changed. Taken together, these results indicate that styrene may cause toxic effect in rat sperm cells by enhancing oxidative stresses.

• 한국수정란이식학회지
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• 제10권1호
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• pp.15-22
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• 1995

Since the turn of the century, scientists have earnestly sought to develop a single laboratory assay or combination of laboratory assays which accurately predict the fertility of a semen sample. Most of these assays have focused on evaluating physical characteristics of sperm such as motility, viability, acrosomal integrity and morphology. In recent years new approches have been used to assess the functional aspects of a sperm that are needed to reach the oocyte, fertilize it and contribute to successful embryo development. Among these techniques are the ability of sperm to undergo a heparin induced acrosome reaction and in vitro fertilization, and the affinity of sperm to bind heparin binding protein. Intensification of research efforts in the area of control of sperm fertilizing ability should be a high priority, in view of undoubted benifits both to our basic understanding of sperm fertilizing ability and to our ability to modify it for Al industry.

• 한국수산과학회지
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• 제36권6호
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• pp.641-645
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• 2003

Spermatogenesis, ultrastructure, and sperm morphology of the Pacific oyster (Crassostrea gigas) were investigated with TEM and SEM. C. gigas sperm were primitive consisting of a head midpiece and tail. Sperm size (head and midpiece) was about 1.78 ${\mu}m$. Sperm morphology was similar to a sharp of a small water jar with a rough surface. Sperm had both anterior nuclear fossa (anf) and posterior nuclear fossa (pnf). Acrosome forms had a hat-like shape. The axial rod was projected in front of the acrosome. C. gigas sperm had four large mitochondria in the midpiece.

• Molecules and Cells
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• 제28권5호
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• pp.441-446
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• 2009

During epididymal transit, mammalian sperm acquire selected proteins secreted by the epididymis. We previously showed that a disintegrin and metalloprotease (ADAM) 7 is expressed specifically in the epididymis and transferred to the sperm surface during epididymal transit. Here, we show that mouse ADAM7 secreted to the epididymal lumen is associated with membranous vesicles known as epididymosomes. Furthermore, we found that ADAM7 can be transferred directly from epididymal vesicles to sperm and that it is an integral plasma membrane protein in sperm. Thus, our study provides new information regarding the unique mode of secretion and interaction of ADAM7 during the epididymis-to-sperm transfer process.