Genetic Variants of B4GALNT2 are Associated with Twinning in Sheep with Potential to Boost Small Ruminant Populations and Mutton Production

Background: Twinning in sheep is an economically important trait. Of the many genes that can affect litter size in sheep, B4GALNT2 is an important member. Genetic variants found in the B4GALNT2 effect the ovulation and can promote twinning in sheep. Keeping in view the importance of prolificacy in sheep, this research was planned to identify the association of B4GALNT2 gene variants with twining in Lohi sheep.Methods: A total of 200 blood samples of female sheep (100 each who gave birth to twins and single sheep respectively) were collected from three sheep farms. DNA was extracted and genotyped for B4GALNT2 (rs410464838). For genotyping of SNPs, a PCR-based restriction fragment length polymorphism assay was used. Data were analyzed by using SPSS and R. Hardy-Weinberg equilibrium was evaluated for both groups of sheep. Association of litter size with B4GALNT2 genetic variants was tested through chi square test.Results: The results of the study showed that genotypes at the B4GALNT2 locus were at Hardy-Weinberg disequilibrium for twin birth. Association analysis revealed a strong association of the AA genotype with twinning. Animals with this genotype were found to be predisposed to having twins. Furthermore, Bayesian analysis reinforced these findings, demonstrating a robust association between the A allele and an increased likelihood of twin births.Conclusion: Overall, the results of this study indicate that the B4GALNT gene is a good candidate for selection of litter size in sheep. If incorporated as part of a marker assisted selection program, it can result in a sustained expansion of small ruminants to increase mutton production and uplift the socioeconomic condition of small ruminant farmers.