• Journal of Embryo Transfer
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• v.14 no.2
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• pp.131-137
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• 1999

This experiment was carried out to investigate the effects of osmolarity of thawing diluents, seminal plasma added in thawing diluents on the sperm viability and the effects of thawing temperature, the temparature of the thawing diluents on the sperm viability and acrosomal morphology of boar spermatozoa by the straw method. The result obtained were summarized as follows: 1. The sperm viablilty after thawing of the frozen semen was shown greater in the high osmolarity(392~492mOsm) than low osmolarity(300mOsm) in thawing diluent. The added levels of seminal plasma in thawing diluent did not affect the viability of frozen-thawed boar semen. 2. In terms of thawing temperature, the sperm viability was shown higher in the frozen semen thawed at 5$0^{\circ}C$ for one min. (p<0.01) than those thawed at 2$0^{\circ}C$ or 37$^{\circ}C$ for one min. The sperm viability was not significant at the diluent temparature of 2$0^{\circ}C$or 37$^{\circ}C$ after thawing: but the sperm viability was higher in thawing diluent at 2$0^{\circ}C$ than in that at 37$^{\circ}C$. However, the effects of thawing temperature and diluent solution on normal acrosomal rate were not significant. 3. Cleavage rates of oocytes fertilized with frozen semen were 46.4% and 43.3%, respectively, which were thawed at 5$0^{\circ}C$ for one min. and then diluted in mBTS medium at 2$0^{\circ}C$or 37$^{\circ}C$. To sum up, the sperm viability was shown greater at the high of thawing diluents of frozen boar semen. In terms of thawing conditions, the sperm viability was shown greater, when semen was thawed at a high temperature for a short time and then diluted at the same temperature as that in the straw.

• Development and Reproduction
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• v.1 no.1
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• pp.29-36
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• 1997

Experiments were performed to study the effects of diluents, cryoprotectant, equilibration time, thawing temperature and addition of BSA and egg yolk. Among the various diluents, Alsever's solution was the best for sperm cryopreservation. A combination of Alsever's solution and 15% ethylene glycol showed the better results than others did. Sperm activity indection and survival rate gradually decreased with the equilibration time. The appropriate thawing temperature was 30 ${\pm}1^{\circ}$C. These results indicate that sperm cryopreservation methods can be developed in tiger puffer.

• Development and Reproduction
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• v.21 no.1
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• pp.79-91
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• 2017

The aim of this study was to compare the efficacy of cryopreservation methods for ex situ conservation of spermatozoa from far eastern catfish, Silurus asotus. The spermatozoa activity index (SAI) and hatching rates were higher in spermatozoa stored in Alserver's solution than those of spermatozoa stored in glucose solution. The SAI and hatching rates in all experimental groups gradually decreased with increasing duration of storage. Additionally, the SAI and hatching rates gradually decreased with increasing thawing temperatures at all storage durations (P<0.05). Based on the SAI and hatching rates, our results suggest that the optimal cryopreservation conditions of catfish spermatozoa involve storage in Alserver's solution with 15% ethylene glycol, and thawing at $25^{\circ}C$. Cryopreservation of spermatozoa is a useful and reliable technique for conserving gene resources and for artificial propagation of far eastern catfish.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1553-1558
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• 2002

This study was carried out to obtain informations regarding the effect of N-acetyl-D-glucosamine in the LEY (lactoseegg yolk) diluent according to incubation time in 5 ml maxi-straw and the effects of freezing rate, thawing temperature and thawing time in the LEN (lactose-egg yolk and N-acetyl-D-glucosamine) diluent on acrosome morphology and motility of frozen-thawed boar sperm. The study showed that the LEN diluent was higher post-thaw NAR (normal apical ridge) acrosome than the LEY diluent for 0.5 h incubation at 37$^{\circ}C$. However, there were no differences between the LEN and LEY diluents on post-thaw sperm motility according to incubation time. The straws frozen from 5.0 cm (20$^{\circ}C$/min) to 17.0 cm (1$^{\circ}C$/min) above the liquid nitrogen surface did not show any significant differences on post-thaw sperm motility. However, the straws frozen above 5.0 cm from the liquid nitrogen surface were higher NAR acrosome than those frozen above 17.0 cm. The post-thaw percentages of motile sperm and NAR acrosome were significantly higher (p<0.05) for the maxi-straws submerged for 40 or 45 sec in a 52$^{\circ}C$ water bath than for 30, 35, 50 or 55 sec. The mean sample temperatures of maxi-straws after 40 or 45 sec submersion were 20.7 or 26.4$^{\circ}C$. In conclusion, the sample temperature of the thawed semen was very important for post-thaw sperm survival in the LEN diluent of 5 ml maxi-straw. When the temperature of the thawed semen was 20.7$^{\circ}C$, the percentages of motile sperm and NAR acrosome were highest.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.12
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• pp.1614-1619
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• 2009

The present study was conducted to observe the effect of increased osmolality of basic tris extender supplemented with trehalose and sucrose on post-thawing quality (motility, progressive motility, viability, the rate of acrosome abnormality, total abnormality and membrane integrity) of Markhoz goat spermatozoa. Fresh semen samples were evaluated for motility and sperm concentration. Only semen samples with motility more than 70% and sperm concentration higher than $3{\times}10^{9}$ sperm/ml were used for cryopreservation. In Exp. 1, trehalose (50, 75 or 100 mM) and sucrose (40, 60 or 80 mM) were added to a basic tris diluent. Based on the results of experiment 1, the goal of Exp. 2 was to investigate the combinational effects of the highest and lowest concentrations ($T_{100}+S_{80}$ or $T_{50}+S_{40}$) of trehalose and sucrose. As the control, semen was diluted and frozen in the tris diluent without trehalose or sucrose. The results in Exp. 1 showed that all evaluated spermatozoa characteristics improved significantly after freezing and thawing (p<0.05) and at the same time the increase of trehalose and sucrose concentrations in basic extenders was seen, with the best results obtained for extenders containing 70 and 100 mM trehalose and 80 mM sucrose. Comparing these results with those of control diluents, the effects of supplementation were significantly (p<0.05) better. In Exp. 2, the results showed no significant differences (p>0.05) between $T_{100}+S_{80}$ and $T_{50}+S_{40}$ extenders, but the results of $T_{50}+S_{40}$were slightly better than obtained with $T_{100}+S_{80}$ diluents. Furthermore, the results of this experiment indicated that the sperm characteristics in the isotonic control extender were significantly (p<0.05) lower than examined extenders. In conclusion, the results of this study indicated that goat sperm can tolerate hypertonic trehalose and sucrose solutions better than isotonic control diluents in the freezing period. In particular, these positive effects have been shown for acrosome integrity, which is very important for the fertilization capacity of sperm. The data indicated that addition of trehalose plus sucrose to the freezing extender can be recommended for cryopreservation of goat spermatozoa, but more data is needed on pregnancy rate, acrosome reaction and IVF to ascertain the real effect.

• Journal of Aquaculture
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• v.20 no.3
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• pp.173-177
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• 2007

An experiment was performed to obtain cryopreservation techniques of starry flounder (Platichthys stellatus) sperm. Milt obtained from 24 males were cryopreserved using two diluents, artificial seminal plasma (ASP) and Stein's solution (SS) with three cryoprotectants, dimethyl sulfoxide (DMSO), methanol, and glycerol concentrated from 5% to 20%. Post-thaw sperm activity (motility and/or speed) revealed the highest in 10% DMSO and 15% methanol in ASP and SS as diluent. Motility and speed of cryopreserved sperm were decreased according to increase of glycerol concentration. To conclude, DMSO was a better cryoprotectant than methanol or glycerol for cryopreservation of starry flounder sperm. Glycerol was incongruent cryoprotectant because of toxic to starry flounder sperm. Most cryopreserved spermatozoa without cryoprotectant showed the enlarged head with granulated chromatin and ruptured plasma membrane by freezing and thawing injuries compared with unfrozen normal spermatozoa.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.545-552
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• 1994

This experiment was carried out to investigate the renditions to maintain good post-thaw motility and viability of canine spermatozoa when the semen was frozen using methanol. The semen from two male dogs which had been proven to be fertile in the previous one year was treated with different compositions of semen diluent and was frozen at different freezing temperatures, When canine semen was frozen at-2$0^{\circ}C$, -6$0^{\circ}C$, or -8$0^{\circ}C$, the spermatozoa frozen and stored at -2$0^{\circ}C$ showed very low post-thaw motility and viability from day 2 to 7 and showed no viability since day 15 after freezing. The spermatozoa frozen and stored at -6$0^{\circ}C$ or -8$0^{\circ}C$ showed higher post-thaw motility and viability on day 2, 1, 15 and 30 after freezing than that frozen and stored at-2$0^{\circ}C$(p<0.01), with no difference between two groups. Among different composition groups of the semen diluents of control(tris + egg yolk + glycerol), egg yolk-free, 히ycerol-free, and tris-free, Prior to freezing, the egg yolk-free diluent showed significantly love. motility and viability than the other diluents(p<0.05). On each thawing day (from day 2 to 15 after freezing), control group showed considerably higher motility and viability than the other groups(p<0.01). The canine spermatozoa frozen and stored at -6$0^{\circ}C$ and -8$0^{\circ}C$ showed gradual decrease of motility from day 2 to 30 after freezing and the spermatozoa of these two groups thawed on day 30 showed considerably love. motility than those thawed on day 2 after freezing, respectively(p<0.01). These results indicate that the freezing temperature of either -6$0^{\circ}C$ or -8$0^{\circ}C$ can be applicable to the freezing method using methanol and also all of the components of the semen diluent including cryoprotectant, buffer and cold-shock buffer are very important to maintain motility and viability of canine spermatozoa in the freezing and thawing procedure.

• Journal of Embryo Transfer
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• v.32 no.1
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• pp.1-8
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• 2017

Cryopreservation of germ cells from genetically proven animals could be a source of restoration tools from the risk of extinction or disappearance of wanted characteristics. Using frozen semen, the genetic gains of Korean native cattle have been increased greatly for 70 years. The preservation of genetic resources as a form of frozen semen straw has limited availability due to the numbers. To circumvent this weakness of frozen semen, we tested two re-freezing methods with different initial thawing temperatures using frozen Korean proven semen and rare breed semen from albino, black and chikso breeders. It has been known that human sperm could resist to cryo-damages by repeated freeze-thaw cycles, but not for Korean proven bulls number (KPN) or for rare breeds. Total 7 frozen semem from brindled(2), black(1), Korean Albino(2) and KPN(1) bulls were used for our research. After thawing straws under $5^{\circ}C/2min$ or $37^{\circ}C/40sec$ with low temperature water bath and thermo jug, spermatozoa were re-diluted with triladyl diluents after first thawing and re-frozen. Sperm motilities were compared between animals and treated groups after re-thawing. Mean values of motility and viability of refrozen/thawed sperm for expansion of the number of straws were significantly higher in $5^{\circ}C$ than in $37^{\circ}C$ (P < 0.05). However, the activity of viable sperm thawed at $5^{\circ}C$ was significantly decreased before refreezing. It is estimated that re-freezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa.

• Journal of Aquaculture
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• v.11 no.1
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• pp.67-75
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• 1998

Experiments were performed to obtain cryopreservation techniques of black seabream (Acanthopagrus schlegeli) sperm. For sperm collection, brood stock reared in recirculating seawater system and fed with the commercial feed during experimental period. The results indicated that following cryopreservation method in block seabream sperm could be employed. Post-thaw survival rate of sperm revealed the highest value ($80{\pm}1.4$%) in 3% sodium citrate as a diluent for the cryopreservation. Cryopreserved sperm diluted with 5.4% glucose showed the highest fertilization rate to the ovulated eggs. Glycerol was a better cryoprotectant than dimethyl sulfoxide in sperm cryopreservation : survival rate and fertilizing capacity of cryopreserved sperm were decreased according to increase of glycerol concentration and varied in renges of 0.8~59.3% and 32.5~69.4% with 5~30% glycerol, respectively. A few of cryopreserved spermatozoa showed the enlarged head with granulated chromatin and ruptured plasma membrane by freezing and thawing injuries compared with unfrozen normal spermatozoa.