Genetic polymorphism in fecundity gene (FecG) among Indiansheep breeds Balangir, Shahabadi and Bonpala

Abstract

FecG (GDF9) is a member of the transforming growth factor-b (TGF- b) superfamily, have been shown to be essential for follicular growth and ovulation. Different mutations in FecG gene caused increased ovulation and infertility in sheep. The present study was designed for screening polymorphism of FecG gene in 250 selected ewes from different sheep flocks representing Balangir (100), Shahabadi (100) and Bonpala (50) by employing forced PCR-RFLP technique. Genomic DNA was extracted from the blood of Balangir, Shahabadi and Bonpala matured ewes with average litter size varying from 1.00± 0.00 to 1.14±0.02 at different parities. Digestion of FecG (GDF9) gene with DdeI restriction enzyme resulted into FecGHH homozygous genotype. In all three sheep breeds, genotypic frequencies of FecGHH were 100% and gene frequency of H allele was unity. This indicates that the FecG gene is fixed in the Balangir, Shahabadi and Bonpala population in the natural habitat. Litter size of Balangir and Bonpala sheep breeds were single but in Shahabadi sheep twin was recorded. In present study all the animals of three breeds were homozygous for FecG and there was no infertility observed in above mentioned breeds in field condition and organized farm, which is not in consonance with previous report. The observed effects could be caused by linkage disequilibrium with other nearby loci. The study revealed that FecG gene is not a reliable genetic marker for selection of high prolificacy in sheep.