Identification of the GDF9 mutation in two sheep breeds by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique

A genetic mutation with major effects on the litter size in sheep was recently identified in the growth differentiation factor (GDF9) gene of the TGF-B super family (transforming growth factor). GDF9 gene has been localized to chromosome 5 in sheep. In order to evaluate the GDF9 gene polymorphism, blood samples were collected randomly from 42 Kordi sheep and 44 Arabic sheep from Kordestan and Khozestan provenance. Exon 1 from GDF9 gene was amplified to produce a 462 bp and exon 2 from GDF9 gene was amplified to produce a 139 bp fragment. The amplified fragment of Exon 1 was digested with Hin6I restriction enzyme and the amplified fragment of exon 2 was digested with DdeI restriction enzyme. Exon 1 revealed two alleles, (denoted A and B) and exon 2 revealed a single allele. In these populations for exon 1, AA and AB genotypes were observed. With attention to the role of a GDF9 in increasing ovulation rate, it seems that this gene can be used as a marker for increasing the twin rate.