Mutation in BMPR-IB gene is associated with litter size in Iranian Kalehkoohi sheep

The single nucleotide polymorphism of BMPR-IB gene (bone morphogenetic protein receptor type IB) was analyzed using PCR-RFLP in Iranian native Kalehkoohi sheep. BMPR-IB which affects the fecundity of Booroola Merino sheep was studied as a candidate gene associated with the prolificacy of Kalehkoohi sheep. Improving the reproductive traits in sheep could be one of the key factors in increasing farm profitability. Major genes for litter size trait provide opportunities for large and rapid increases in the efficiency of sheep production. The same FecB (Booroola) mutation occurred in the BMPR-IB gene in Kalehkoohi sheep as found in Booroola Merino. Allele frequency for B and + was 0.35 and 0.65 respectively. The BB, B+ and ++ genotypes have been identified with the 0.13, 0.446 and 0.424, respectively. The Kalehkoohi sheep with genotypes BB and B+ had 0.52 and 0.35 lambs, more than the homozygous wild-type, respectively (P < 0.01). No significant difference was observed between B+ and BB in litter size. Also the effect of parity and flock weren’t significant in this study. Results of the present study support the concept that BMPR-IB significantly affected litter size and was associated with litter size in Kalehkoohi sheep and thus it could be used for Marker-assisted selection programmers for the genetic improvement of reproductive characteristics in this breed.