Polymorphism Analysis of FecB and BMP15 Genes in Kenguri and Kenguri × NARI Suwarna Sheep

Abstract— Sheep production in India is constrained by low reproductive efficiency, with litter size being a major limiting factor in improving productivity. Prolificacy in sheep is largely regulated by fecundity genes such as Booroola fecundity (FecB/BMPR1B) and BMP15, which directly influence ovulation rate and litter size. The present investigation was carried out to detect polymorphisms in these two genes in Kenguri and Kenguri × NARI Suwarna (F1) sheep maintained at the Livestock Research and Information Centre, Veterinary College, Bidar. Blood samples were collected from 30 Kenguri and 30 crossbred sheep. Genomic DNA was isolated using the phenol–chloroform method and evaluated for purity and concentration. PCR amplification was performed using specific primers to amplify a 190 bp fragment of FecB and a 434 bp fragment of BMP15. The PCR products were subjected to restriction fragment length polymorphism (RFLP) using AvaII and StuI restriction enzymes, respectively, and separated by agarose gel electrophoresis. In Kenguri sheep, the FecB locus was monomorphic, with all animals showing the wild-type (++) genotype. However, in the Kenguri × NARI Suwarna (F1) crossbred population, three genotypes were identified: BB (0.16), B+ (0.50), and ++ (0.34). The corresponding allele frequencies were B = 0.41 and + = 0.59. A Chi-square test for Hardy–Weinberg equilibrium revealed significant deviation (χ² = 7.82, p < 0.05) in the crossbred group, indicating possible selection pressure, genetic drift, or non-random mating. At the BMP15 locus, no polymorphism was detected, and all animals across both populations were found to be monomorphic for the wild-type allele. The results clearly demonstrate the successful introgression of the FecB allele through crossbreeding with the NARI Suwarna strain, thereby enhancing the genetic potential for higher prolificacy in Kenguri sheep. These findings provide molecular evidence supporting the role of targeted crossbreeding in improving reproductive traits. The absence of variability at the BMP15 locus suggests that FecB plays a more prominent role in this population.