Effect of Polymorphisms in Some Candidate Genes on Twinning in Cross Breeds of Shall and Romanov

This study was carried out to identify polymorphisms of BMP15, GDF9 and BMPRIB genes in cross- bred of Romanov×shal sheep. For this reason 79 blood samples were collected from a flock in Gonbad kavous city in Golestan province. DNA was extracted using modified salting out method. Polymerase chain reaction was done by specific primers for amplification of two fragments with 141and 153 bp from exon 2 of BMP15, one fragment with 190 bp from BMPR-IB gene and two fragment with 462 bp, 139bp from exon 1and 2 of GDF9 genes, respectively. The results obtained from digested PCR products did not confirm the existence of mutation in BMp15, BMPR-1B and in exon 2 of GDF9 marker site. While, polymorphism was observed in exon 1 of GDF9 marker site and the heterozygotes were estimated as 0.11 in this population.