Investigation of <i>GDF9</i> and <i>BMP15</i> Polymorphisms in Mehraban Sheep to Find the Missenses as Impact on Protein

Abstract

Utilization of fecundity genes such as <em>GDF9</em> and <em>BMP15</em> can help improve reproductive traits in sheep breeding programme. To evaluate effects of missense mutations on protein function, the polymorphisms of <em>GDF9</em> and <em>BMP15</em> genes were screened in twelve mehraban sheep using DNA sequencing, followed by protein structure modeling. Six single nucleotide polymorphism (SNPs) known as <em>FecG</em> mutations (G1-G6), were detected in exons 1 and 2 of <em>GDF9</em> gene. Mutations of G1 (<em>GDF9</em> exon 1 g.2118 G>A), G4 (<em>GDF9</em> exon 2 g.3451 T>C) and G6 (<em>GDF9</em> exon 2 g.3974 G>A) have shown amino acid substitution. None polymorphism was detected in exon 1 and exon 2 of <em>BMP15</em> gene. Based on identified polymorphisms, individuals were classified into three haplotypes of wild haplotype (without mutation), haplotype A (simultaneous mutations of G1, G2, G3 and G4) and haplotype B (simultaneous mutations of G5 and G6). The 3D-structure of GDF9 protein in A and B haplotypes was rotated 90˚ and 45˚ than wild haplotype, respectively. The missenses G1/p.Arg87His, G4/p.Glu241Lys and G6/p.Val332Ile variants were benign. However both the missenses of G7/p.Val371Met and G8/p.Ser315Phe were probably damaging. Phylogenetic tree of <em>GDF9</em> gene revealed that individuals with A and B haplotypes were distinct from wild haplotypes with bootstrapping values of 63 and 76, respectively. In conclusion, GDF9 protein in A and B haplotypes showed a higher performance than wild haplotype due to synergism effects of simultaneous mutations. These types of mutations with effect on turn and helix of <em>GDF9</em> conservative regions showed physical and functional interaction with TGFβ proteins.