Effects of different extenders on DNA integrity of boar spermatozoa following freezing-thawing.
The sperm-rich fraction, collected from eight mature Yorkshire boars, was frozen in an extender containing 9% LDL (w/v), 100mM trehalose, or 20% yolk (v/v), respectively. Sperm DNA integrity was assessed using the single-cell gel electrophoresis (SCGE). Other sperm quality characteristics such as motility, acrosome and membrane integrity were also monitored. The results showed that freezing-thawing caused an increase in sperm DNA fragmentation, and extender containing 9% LDL could significantly protect sperm DNA integrity (P<0.05) from the damage caused by cryopreservation and decrease DNA damages compared with extender containing 100mM trehalose and 20% yolk (v/v). No significant difference in damaged DNA was detected between frozen and unfrozen semen samples for extender of 9% LDL and 100mM trehalose, but cryopreservation could increase the degree of DNA damage (P<0.05), the percentage of damaged DNA degree of grade 2 and 3 was significantly increased. The deterioration in post-thaw sperm DNA integrity was concurrent with reduced sperm characteristics. The data here demonstrated that the cryoprotectant played a fundamental role in reducing boar sperm DNA damage and protecting DNA integrity. It can be suggested that evaluation of sperm DNA integrity, coupled with correlative and basic characteristics such as motility, acrosome integrity and membrane integrity, may aid in determining the quality of frozen boar semen.
Hu
Jian-hong
JH
College of Animal Science and Technology, Northwest A & F University, Yangling, ShaanXi Province 712100, PR China.
Li
Qing-wang
QW
Jiang
Zhong-liang
ZL
Li
Wen-ye
WY
D000177:Acrosome / Q000187:drug effects; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects; D020552:Comet Assay; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004249:DNA Damage / Q000187:drug effects*; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility; D013094:Spermatozoa / Q000187:drug effects* / Q000648:ultrastructure; D034421:Sus scrofa
D003451:Cryoprotective Agents