Polymorphism of the BMP15 (FecX) gene and its association with litter size in local Iraqi goats

The present research was carried out at the Ruminants Research Station of the General Authority for Agricultural Research / Ministry of Agriculture in Abu Ghraib for the period from 15/2/2025 to 15/9/2025 investigated genetic variation in the BMP15 gene and its relationship to litter size (number of kids) in does from Northern Iraq. Blood samples were collected from 60 does, which were divided into two groups (high and low prolificacy) based on their reproductive history. Using PCR-RFLP, SSCP, and DNA sequencing, the study identified several variants in the BMP15 gene, including the FecXI and FecXH mutations as well as novel mutations. The results showed a highly significant association between these polymorphisms and litter size (p < 0.001). Carrying a single copy of the heterozygous genotype was associated with increased litter size; litter size increased by 0.56 kids in the presence of the FecXI (g.321C>T) and FecXH (g.528G>T) mutations. Bioinformatic analysis and structural protein modeling of the affected functional regions indicated that most of the examined mutations induce structural changes in the resulting protein. According to the integrated statistical model, genetic effects accounted for 65% of the total phenotypic variance. These findings provide valuable data for breeding and genetic improvement programs and indicate that genomic markers can enhance the reproductive efficiency of goats.