RESUMO
Polymorphisms in growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) genes have been found to be associated with litter size in goats across the globe. Our previous study detected single-nucleotide polymorphisms (SNPs) in GDF9 and BMP15 genes associated with litter size in Black Bengal, Bangladesh's primary native goat breed. However, Jamunapari and crossbred goats in Bangladesh are yet to be investigated for litter size-associated polymorphisms. In this study, we screened Jamunapari and crossbred (50% Black Bengal × 50% Jamunapari) goats to identify polymorphisms in the GDF9 and BMP15 genes and to assess the association between identified SNPs and litter size. The genomic DNA from 100 female goats (50 Jamunapari and 50 crossbred) was used in polymerase chain reactions (PCRs) to amplify exon 2 of the GDF9 and exon 2 of the BMP15 genes. PCR products were sequenced employing the BigDye Terminator cycle sequencing protocol to identify SNPs. We used a generalized linear model to perform the association analysis for identified SNPs and litter size. Seven SNPs were identified, of which four, C818CT, G1073A, G1189A, and G1330T, were in the GDF9 gene and three, G616T, G735A, and G811A, were in the BMP15 gene. G735A was a synonymous SNP, whereas the remaining were non-synonymous SNPs. Identified SNP loci in GDF9 were low polymorphic (PIC < 0.25), while loci in BMP15 were moderately polymorphic (PIC ≥ 0.25). The genotypes at the G1330T locus had a significant (p < 0.05) difference in litter size in Jamunapari goats, but no significant difference was observed for all genotypes at other loci. Therefore, the G1330T loci could be useful as a marker in marker-assisted selection for litter size traits in goats of Bangladesh.
