Association of GDF9 Gene Polymorphism with Sperm Quality and Quantity Traits in Iranian Holstein Bulls

The use of artificial insemination in dairy cattle industry may improve the results of selection for production traits. This study attempts to evaluated effect of GDF9A625T and GDF9A489T candidate gene polymorphism on the sperm quality and quantity traits in Iranian bulls. A total of 108 samples of blood and semen was collected of A. I. bulls were born between 1989-2016 years. The GDF9A625T and GDF9A489T SNPs was determined by PCRRFLP with DraI and NsiI enzymes, respectively. In A625T site, A (351 and 25 bp) and T (376 bp) alleles and in A489T site, A (184 and 24 bp) and T (208bp) alleles was obtained and also three AA, AT and TT genotypes in two marker sites were observed. The frequency results of GDF9A625T site showed that the T allele relative to the A allele was more frequent in Iranian Holstein bulls (0.6343 vs 0.3657) and 44.44, 37.98 and 17.95 percent of bulls had TT, AT and AA genotypes, respectively. In GDF9A625T site, the T allele frequency was more than A allele (0.602 vs 0.398) and 40.82, 38.78 and 20.14 percent of bulls had TT, AT and AA genotypes, respectively. Analysis of variance revealed that the effects of both loci were significant effect on sperm quality in Iranian Holstein bulls. The result of means comparison between genotypes in two marker sites showed that bulls with AT genotype significantly high value in quantitative trait and AA genotype was significantly higher in qualitative trait. Results of this research showed that these marker sites can be beneficial in genomic selection.