Polymorphisms in the bone morphogenetic protein 15 gene and their effect on sperm quality traits in Chinese Holstein bulls.

Bone morphogenetic protein 15 (BMP-15) expression has been detected in the testis, but its roles in this organ has not been well elucidated. We evaluated polymorphisms of the BMP-15 gene by PCR-SSCP and PCR-RFLP in 212 Chinese Holstein bulls, and investigated possible associations with sperm quality traits, including semen volume per ejaculate, sperm density, fresh sperm motility, thawed sperm motility, acrosome integrity rate, and abnormal sperm rate. A single nucleotide polymorphism (C5697T) in intron 1 of the BMP-15 gene was identified in these bulls. Age was found to have significant effects on both fresh sperm motility and abnormal sperm rate. A significant effect of genotype on fresh sperm motility was also observed. Least square analysis showed that CT genotype bulls had significantly lower fresh sperm motility than CC or TT genotype bulls. In conclusion, BMP-15 should be considered as a potential genetic marker for sperm quality, based on its association with fresh sperm motility.