Background:Female sperm storage(FSS),the maintenance of sperm inside the female reproductive tract for an extended period of time,is pervasive among organisms with internal fertilization.Because FSS enables asynchrono...Background:Female sperm storage(FSS),the maintenance of sperm inside the female reproductive tract for an extended period of time,is pervasive among organisms with internal fertilization.Because FSS enables asynchronous mating and fertilization,it could be extremely important to reproduction.However,the physiological mechanisms underlying prolonged preservation and maintenance are poorly understood.Here,we used chicken,a typical oviparous animal,to determine the mechanisms ensuring sperm functionality in sperm storage tubules(SSTs).Results:We performed an insemination experiment on over two thousand hens at two periods,and found that the FSS capabilities varied widely among individuals.Except for the differences in the SST density between the two groups with distinct FSS abilities,we quantitatively profiled small-molecule metabolites derived from SST cells,and identified 28 metabolites with differential expression.In particular,high levels of lipids,fatty acids and lipid peroxidation product were observed in hens with low FSS capability.Pathway analysis showed that these differential metabolites were significantly enriched in the biosynthesis of unsaturated fatty acids.Moreover,we detected the total antioxidant capacity and lipid peroxidation level of SSTs,and found that chickens with a lower FSS ability had a significantly higher content of lipid peroxidation end-product,which was 2.4-fold greater than chickens with a higher FSS capability,and no significant difference was found in the total antioxidant capacity between these two groups.Conclusions:Our findings reveal that the long-term storage of sperm and the maintenance of their function in the female reproductive tract require an adequate microenvironment.The superabundance of fatty acids secreted by SST cells had detrimental effects on sperm storage in the female reproductive tract.Lipid peroxidation produces toxic biological substances that may cause irreversible damage to resident spermatozoa,resulting in short-term sperm retention and decreased fertility展开更多
Although it is generally understood that the testes recruited kidney ducts for reproductive function during the evolution of vertebrates, little is understood of the biological significance of the adaptation. In the c...Although it is generally understood that the testes recruited kidney ducts for reproductive function during the evolution of vertebrates, little is understood of the biological significance of the adaptation. In the context of the evolution of the mammalian epididymis, this report provides evidence that a major role of the epididymis is to enhance a male＇s chance of achieving paternity in a competitive mating system. A unique example of sperm cooperation in monotremes is used as evidence that the epididymis produces sperm competition proteins to form groups of 100 sperm into bundles that have a forward motility nearly thrice that of individual spermatozoa. As it required 3-h incubation in vitro under capacitation conditions to release motile sperm from the bundles, it is suggested that the monotremes provide an example of capacitation that is quite different from capacitation in higher mammals. It is suggested that variation between species in the intensity of sperm competition could explain the variation that occurs between species in the amount of post-testicular sperm maturation and storage in the epididymis, an explanation of why the human epididymis does not play as important a role in reproduction as the epididymis of most mammals. （Asian J Androl 2007 July; 9： 493-499）展开更多
This study evaluated sperm viability over time, after dilution and refrigerator storage of fresh semen extended in either synthetic cauda epididymal plasma (CEP2), or in a low sodium medium (CJ2) supplemented with eit...This study evaluated sperm viability over time, after dilution and refrigerator storage of fresh semen extended in either synthetic cauda epididymal plasma (CEP2), or in a low sodium medium (CJ2) supplemented with either AlbuMAX or egg yolk. Semen collected weekly for 4 weeks from 4 bulls and assigned within bulls, across treatments. After extension in either CEP2, or CJ2 containing either egg yolk or AlbuMAX, semen was cooled to 4°C, and evaluated for 7 days. A computer assisted sperm analysis (CASA) system was used for sperm evaluation. Particular emphasis was placed on sperm motility since it is the single most important sperm parameter influencing bull fertility. Total and progressive motility of sperm in CEP2 and CJ2-AlbuMAX were similar (P = 0.85 and P = 0.23, respectively), but both were lower (P < 0.01) when compared to CJ2-yolk. Fewer sperm had rapid motility in CEP2 and CJ2-AlbuMAX compared to CJ2-yolk (P < 0.01). Sperm straightness and linearity were greater in CJ2-AlbuMAX and CJ2-yolk than in CEP2 (P < 0.01). Mean velocity (VAP) and linear velocity (VSL) were greater (P < 0.01) in CJ2-AlbuMAX than either CEP2 or CJ2-yolk. The calculated curvilinear velocity (VCL) of spermatozoa in CEP2 was lower than CJ2-AlbuMAX (P = 0.01), but similar with CJ2-yolk (P = 0.54). Overall, every sperm parameter measured by the CASA system was equal to or higher for sperm stored 7 days in CJ2 medium as compared with CEP2. The CJ2 extender supplemented with egg yolk is a viable alternative for storing fresh bovine semen.展开更多
The aim was to discuss the optimal storage environment and proper insemination time after thawing of 0.25 mL straw frozen semen. Straw frozen semen was thawed at 40 ℃ for 20 s, and then stored at 0 -4 ℃, 14 - 16 ℃,...The aim was to discuss the optimal storage environment and proper insemination time after thawing of 0.25 mL straw frozen semen. Straw frozen semen was thawed at 40 ℃ for 20 s, and then stored at 0 -4 ℃, 14 - 16 ℃, 25 -27 ℃ for 2, 4, 6, 8 and 10 h, respectively. The sperm motility was detected. After thawing, semen was stored at 0 - 4 ℃ and 14 - 16 ℃ for 10 h. Their sperm motilities （0.434 ±0. 016 7 and 0.423 ±0.019 6） had no significant differences （P 〉 0.05） with initial thawing motility （0.441 ± 0.030）. Sperm motility reduced as the storage time prolonged at 25 -27 ℃. Sperm motility after 6 h had signifi- cant differences with that of initial thawing motility （P 〈 O. 05 ）, and sperm motilities after 8 and 10 h showed extremely significant differences （P 〈 0.01 ）. Thus, sperm motility after thawing was still very high after stored at 0 -4 ℃ and 14 - 16 ℃ within 10 h, which met the requirements for insemination. Under this temperature and time ranges, sperm could be carried over long distances, which had small effects on sperm quality and reached the expected insemination effects. However, under the temperature of 25 - 27 ℃, semen should be used for insemination within 6 h after thawing.展开更多
基金This work was supported by Programs for Changjiang Scholars and Innovative Research in Universities(IRT_15R62)China Agriculture Research Systems(No.CARS_40).
文摘Background:Female sperm storage(FSS),the maintenance of sperm inside the female reproductive tract for an extended period of time,is pervasive among organisms with internal fertilization.Because FSS enables asynchronous mating and fertilization,it could be extremely important to reproduction.However,the physiological mechanisms underlying prolonged preservation and maintenance are poorly understood.Here,we used chicken,a typical oviparous animal,to determine the mechanisms ensuring sperm functionality in sperm storage tubules(SSTs).Results:We performed an insemination experiment on over two thousand hens at two periods,and found that the FSS capabilities varied widely among individuals.Except for the differences in the SST density between the two groups with distinct FSS abilities,we quantitatively profiled small-molecule metabolites derived from SST cells,and identified 28 metabolites with differential expression.In particular,high levels of lipids,fatty acids and lipid peroxidation product were observed in hens with low FSS capability.Pathway analysis showed that these differential metabolites were significantly enriched in the biosynthesis of unsaturated fatty acids.Moreover,we detected the total antioxidant capacity and lipid peroxidation level of SSTs,and found that chickens with a lower FSS ability had a significantly higher content of lipid peroxidation end-product,which was 2.4-fold greater than chickens with a higher FSS capability,and no significant difference was found in the total antioxidant capacity between these two groups.Conclusions:Our findings reveal that the long-term storage of sperm and the maintenance of their function in the female reproductive tract require an adequate microenvironment.The superabundance of fatty acids secreted by SST cells had detrimental effects on sperm storage in the female reproductive tract.Lipid peroxidation produces toxic biological substances that may cause irreversible damage to resident spermatozoa,resulting in short-term sperm retention and decreased fertility
文摘Although it is generally understood that the testes recruited kidney ducts for reproductive function during the evolution of vertebrates, little is understood of the biological significance of the adaptation. In the context of the evolution of the mammalian epididymis, this report provides evidence that a major role of the epididymis is to enhance a male＇s chance of achieving paternity in a competitive mating system. A unique example of sperm cooperation in monotremes is used as evidence that the epididymis produces sperm competition proteins to form groups of 100 sperm into bundles that have a forward motility nearly thrice that of individual spermatozoa. As it required 3-h incubation in vitro under capacitation conditions to release motile sperm from the bundles, it is suggested that the monotremes provide an example of capacitation that is quite different from capacitation in higher mammals. It is suggested that variation between species in the intensity of sperm competition could explain the variation that occurs between species in the amount of post-testicular sperm maturation and storage in the epididymis, an explanation of why the human epididymis does not play as important a role in reproduction as the epididymis of most mammals. （Asian J Androl 2007 July; 9： 493-499）
文摘This study evaluated sperm viability over time, after dilution and refrigerator storage of fresh semen extended in either synthetic cauda epididymal plasma (CEP2), or in a low sodium medium (CJ2) supplemented with either AlbuMAX or egg yolk. Semen collected weekly for 4 weeks from 4 bulls and assigned within bulls, across treatments. After extension in either CEP2, or CJ2 containing either egg yolk or AlbuMAX, semen was cooled to 4°C, and evaluated for 7 days. A computer assisted sperm analysis (CASA) system was used for sperm evaluation. Particular emphasis was placed on sperm motility since it is the single most important sperm parameter influencing bull fertility. Total and progressive motility of sperm in CEP2 and CJ2-AlbuMAX were similar (P = 0.85 and P = 0.23, respectively), but both were lower (P < 0.01) when compared to CJ2-yolk. Fewer sperm had rapid motility in CEP2 and CJ2-AlbuMAX compared to CJ2-yolk (P < 0.01). Sperm straightness and linearity were greater in CJ2-AlbuMAX and CJ2-yolk than in CEP2 (P < 0.01). Mean velocity (VAP) and linear velocity (VSL) were greater (P < 0.01) in CJ2-AlbuMAX than either CEP2 or CJ2-yolk. The calculated curvilinear velocity (VCL) of spermatozoa in CEP2 was lower than CJ2-AlbuMAX (P = 0.01), but similar with CJ2-yolk (P = 0.54). Overall, every sperm parameter measured by the CASA system was equal to or higher for sperm stored 7 days in CJ2 medium as compared with CEP2. The CJ2 extender supplemented with egg yolk is a viable alternative for storing fresh bovine semen.
基金Supported by the Technology Research and Demonstrational Popularization Project of Beijing Vocational College of Agriculture(XY-YF-15-07)(XY-YF-14-21)
文摘The aim was to discuss the optimal storage environment and proper insemination time after thawing of 0.25 mL straw frozen semen. Straw frozen semen was thawed at 40 ℃ for 20 s, and then stored at 0 -4 ℃, 14 - 16 ℃, 25 -27 ℃ for 2, 4, 6, 8 and 10 h, respectively. The sperm motility was detected. After thawing, semen was stored at 0 - 4 ℃ and 14 - 16 ℃ for 10 h. Their sperm motilities （0.434 ±0. 016 7 and 0.423 ±0.019 6） had no significant differences （P 〉 0.05） with initial thawing motility （0.441 ± 0.030）. Sperm motility reduced as the storage time prolonged at 25 -27 ℃. Sperm motility after 6 h had signifi- cant differences with that of initial thawing motility （P 〈 O. 05 ）, and sperm motilities after 8 and 10 h showed extremely significant differences （P 〈 0.01 ）. Thus, sperm motility after thawing was still very high after stored at 0 -4 ℃ and 14 - 16 ℃ within 10 h, which met the requirements for insemination. Under this temperature and time ranges, sperm could be carried over long distances, which had small effects on sperm quality and reached the expected insemination effects. However, under the temperature of 25 - 27 ℃, semen should be used for insemination within 6 h after thawing.
