title: Effects of glycerol on apoptotic signaling pathways during boar spermatozoa cryopreservation.
abstract: Artificial insemination (AI) with post-thawed boar spermatozoa results in low farrowing rates and reduced litter sizes mainly due to cryoinjury or damages to spermatozoa during cryopreservation. Low viability and motility of post-thawed boar spermatozoa are highly associated with apoptosis during cryopreservation. Although glycerol is widely used a cryoprotectant (CPA) for boar spermatozoa cryopreservation, the mechanism and relationship between glycerol and apoptosis-related gene expression needs to be clarified. In this study, we treated boar spermatozoa with different concentrations of glycerol in lactose egg yolk (LEY) extender to evaluate the apoptosis-related gene expression and protease activities of caspases. These results show that: (1) low concentrations of glycerol (2% and 3%) were more suitable for boar spermatozoa cryopreservation; (2) apoptosis-related genes involved in intrinsic mitochondrial and extrinsic death receptor apoptotic signaling pathways were widely expressed in different concentrations of glycerol treated boar spermatozoa; (3) there was a significant positive correlation (r=0.840, P=0.037) between the percentage of Annexin V(+)/PI(+) staining spermatozoa and caspase-6/9 protease activity. In conclusion, 2% and 3% glycerol have the best anti-apoptotic effects, and the expression of Fas/FasL and Bcl-2/Bax have a strong correlation with spermatozoa parameters.
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan Province 625014, PR China. Electronic address: zengchj@sicau.edu.cn.
authors.forename: Changjun
authors.initials: C
authors.lastname: Zeng
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan Province 625014, PR China.
authors.forename: Keyi
authors.initials: K
authors.lastname: Tang
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan Province 625014, PR China.
authors.forename: Lian
authors.initials: L
authors.lastname: He
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan Province 625014, PR China.
authors.forename: Wenpei
authors.initials: W
authors.lastname: Peng
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan Province 625014, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Ding
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan Province 625014, PR China.
authors.forename: Donghui
authors.initials: D
authors.lastname: Fang
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan Province 625014, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000378:metabolism*; D004530:Egg Yolk / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D007785:Lactose / Q000378:metabolism; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D015398:Signal Transduction; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology* / Q000378:metabolism; D013552:Swine / Q000378:metabolism*
chemical_list: D003451:Cryoprotective Agents; D020169:Caspases; D007785:Lactose; D005990:Glycerol
keywords: Apoptosis; Boar spermatozoa; Cryopreservation; Glycerol; Signaling pathway