Studies On Molecule Markers Of Semen Quality Related Genes In Holstein Bull

According to the reproductive endocrine regulatory mechanism of spermatogenesis, the genes of reproductive hormones and their receptors,as well as other reproductiion related genes were selected as the candidates in the present study.These genes included Follicle stimulating hormone receptor gene(FSHR),Inhibinαsubunit gene(INHA), InhibinβA subunit gene(INHβA),Gonadotropin-releasing hormone receptor gene (GnRHR),Androgen receptor gene(AR),Aromatase CYP19 gene(CYP19) and Heat shock protein 70 genes(HSP70).The polymorphisms and therir associations with the semen quality traits such as average ejaculate volume,sperm density,sperm motility, acrosome intact rate and deformity rate of these genes were analyzed in 122 Holstein bulls from two different breeding station by PCR-RFLP and PCR-SSCP.The results were showing as follows:1.The Taq I polymorphism was detected in FSHR gene in the bull groups by PCR-RFLP,and resulted in three genotypes named AA,AB and BB.The genotype frequency was the highest in BB,and the lowest in AA.They had no significant difference in the two different source groups(P＞0.05).The allele B was dominant in the sample groups.Association analysis indicated that the bulls with AB genotype was higher than AA genotype on initial sperm motility(P＜0.05) and acrosome intact rate (P＜0.01),which of BB genotype was between them.It can be indicated that the AB genotype of FSHR gene had a positive effect on nitial sperm motility and acrosome intact rate,and the allele B was dominant.2.The Msp I polymorphism was detected in INHA gene in the bull groups by PCR-RFLP,and resulted in three genotypes named AA,AB and BB.The genotype frequency was the highest in AA,and the lowest in BB.They had no significant difference in the two different source groups(P＞0.05).The allele A was dominant in the sample groups.Association analysis indicated that the bulls with AA genotype was higher than AB genotype on average ejaculate volume,initial sperm motility and deformity rate,which of AB genotype was higher than BB genotype on them.The bulls with AA genotype had the highest sperm density,which with AB genotype had the highest acrosome intact rate.However,the differences were no siginificant(P＞0.05).It can be indicated that the Msp I polymorphism of INHA gene had no siginificant effect on the Holstein bull semen quality traits.3.The Sty I polymorphism was detected in INHβA gene in the bull groups by PCR-RFLP,and resulted in three genotypes named AA,AB and BB.The genotype frequency was the highest in AB,and the lowest in BB.They had significant difference in the two different source groups(P＜0.01).The allele A was dominant in the sample groups.Association analysis indicated that the bulls with AB genotype had the highest initial sperm motility,which with BB genotype were simillar to these with AA genotype. The bull with AA genotype was better than BB genotype on acrosome intact rate and deformity rate,and the beneficial effect of the genotypes all showed AA＞AB＞BB.The bulls with BB genotype had higher average ejaculate volume and sperm density than these with AB genotype.However,these differences were no siginificant(P＞0.05).It can be indicated that the Sty I polymorphism of INHβA gene had no siginificant effect on the Holstein bull semen quality traits.4.The mutation site between 522bp and 718bp of HSP70 gene was not detected in two source Holstein bull groups by PCR-SSCP.5.The A-G mutation of GnRHR gene,A-G mutation of AR gene and T-C mutation of CYP19 were not detected in two source Holstein bull groups by PCR-RFLP.