Association of Exon 2 of BMP15 Gene with the Litter Size in the Raini Cashmere Goat

The Raini Cashmere goat is one of the Iranian goat breeds with a high economic value on international markets due to its high production and high quality. The BMP15 gene regulates granulose cell proliferation and differentiation by promoting granulosa cell mitosis, suppressing follicle-stimulating hormone receptor expression, and stimulating the kit ligand expression. This gene plays a pivotal role in female fertility in mammals and is a potential candidate gene for prolificacy in marker-assisted selection. Thus, the aim of this study was to detect the polymorphism in exon 2 of BMP15 gene and its association with the litter size (number of the offspring born per doe) in 200 Raini Cashmere goats. The genomic DNA was extracted from the whole blood. PCR products were separated on the agarose gel. Amplification products had a good specificity. The amplified fragments were digested with HinfI enzyme (PCR-RFLP) and were genotyped on the 3.5% agarose gel. Allelic frequencies were estimated as 0.7 and 0.3 for B and b alleles, respectively. The Chi-square test showed that the population was in Hardy-Weinberg equilibrium. The observed number of the alleles, the effective number of the alleles, average heterozygosity, the Nei index, and the Shannon's Information index were 2.00, 1.70, 0.41, 0.41, and 0.60 respectively showing a high genetic diversity for the BMP15 gene in the Cashmere Raini goat. For association study between the genotypes and the litter size, the GLM procedure in the SAS software was used. The results of the statistical analysis showed that the effect of the genotype on the litter size was significant (P<0.01) and the heterozygote genotypes had the highest litter size, suggesting that this polymorphism could be used as a molecular marker to improve the prolificacy in Raini Cashmere goats.