Validation study of c.746A>G SNP of BMPR1B gene associated with litter size in sheep genetic resources of Bangladesh

The bone morphogenetic protein receptor type 1B (BMPR1B) gene is one of the major fecundity genes that have been investigated in different sheep populations worldwide for its association with prolificacy traits. The present study was performed to validate the association of c.746A>G SNP of BMPR1B gene with litter size trait in different sheep populations of Bangladesh. A total of 192 blood samples were collected from ewes of both farmers' and institutional flocks comprising sheep populations of Jamuna River Basin (JRB), Barendra (BAT), Coastal (COR), Garole (GAR) and Muzaffarnagari (MUZ). Genotyping of the individuals was performed using PCR-RFLP method and single marker association analysis was carried out to evaluate the relationships between resultant genotypes and litter size trait. The prolificacy attributed homozygous FecBBB genotype frequencies were 66, 50 and 55%, respectively in JRB, BAT and GAR populations whereas it was only 0-2% in MUZ and COR populations. Association analysis revealed highly significant (P<0.001) association of litter size trait with genotypes and populations. The mean litter sizes of JRB, BAT, GAR, COR and MUZ were 2.17±0.15, 1.88±0.07 1.90±0.10, 1.12±0.03, and 1.02±0.02, respectively. The prolific JRB, BAT, and GAR ewes produced 0.67 to 0.83 more lambs per lambing than their wild type FecB++ counterparts. Thus, this study validated the potential contribution of the investigated c.746A>G SNP that could be applied in marker assisted selection (MAS) program for identifying high prolific ewes in order to improve litter size trait at the population level.