Association of GDF9 and BMP15 Genes Polymorphism with Twinning in Markhoz Goat

Twinning is one of the most important economic traits in goat production, which is influenced by either small or major gene effects. In recent decades, it has been recognized that two members of growth factors originated from oocytes namely GDF9 and BMP15 are essential for follicular development and ovulation. The aim of the current study was to survey the polymorphism of two GDF9 and BMP15 genes and their genotype patterns association with twining rate in Markhoz goat. Blood samples were randomly taken from 50 Markhoz goats and DNA extraction was performed by a salting-out modified method. Polymerase chain reactions (PCR) were employed to amplify a fragment with 862 base pairs from exon 2 of BMP15 gene and 995 base pairs fragment from exon 2 of GDF9 gene. The PCR products after digestion by Hinf1 enzyme were electrophoresed on 3% agarose gel and the animals' genotypes were determined by banding patterns. In the BMP15 gene, the frequencies of B and b alleles were 0.96 and 0.04, respectively; and the frequencies of BB, Bb and bb genotypes were 0.94, 0.04 and 0.02, respectively. Also, the frequencies of A and a alleles in GDF9 gene were 0.68 and 0.32, respectively; and the frequencies of AA, Aa and aa genotypes were 0.60, 0.16 and 0.24, respectively. The Nei’s index, Polymorphism information content and expected heterozygosity in the BMP15 gene were 0.47, 0.077 and 0.08, respectively; and corresponding values in the GDF9 gene were 0.34, 0.4 and 0.43, respectively. The results showed that the effects of BMP15, GDF9 and interaction of two loci genotypes on twinning trait were significant indicating that although the GDF9 and BMP15 genes in Markhoz goats have low to moderate polymorphism, they play an important role in twining rate. The present information may be useful in breeding programs of Markhoz goats and could be used in selection strategies.