Association Between BMP15 and Gdf9 Gene Polymorphisms and Litter Size in Dorper and Local Sheep

Information on genetic diversity related to prolific traits in Dorper and Local sheep raised in Indonesian environments is still limited.This study aimed to identify polymorphisms in the BMP15 and GDF9 genes and evaluate their associations with litter size traits in full-blood Dorper and Local ewes at the CV. Kambing Burja farm, East Java, Indonesia. A total of 40 ewes (17 Dorper and 23 Local) were assessed for birth type and litter size. DNA was extracted from blood samples and analyzed using PCR, PCR-RFLP, and DNA sequencing. Six loci were examined: BMP15 g.6393 C>G, BMP15 g.6637 C>T, BMP15 g.6790 C>T, GDF9 g.792 G>A, GDF9 g.3010 G>A, and GDF9 g.913 T>C. Genotype and allele frequencies, Hardy–Weinberg equilibrium, heterozygosity, polymorphic information content (PIC), and associations with litter size were analyzed using SPSS version 26. The results showed that the BMP15 g.6393, BMP15 g.6637, BMP15 g.6790, GDF9 g.3010, and GDF9 g.913T loci were monomorphic in both breeds and were not associated with litter size. However, a missense mutation at GDF9:g.792G>A in exon 1 was detected in Local sheep, producing two genotypes (GG and GA), while Dorper sheep remained monomorphic. The GA genotype frequency in Local sheep was 0.17, and GG was 0.83, with allele frequencies of 0.91 (G) and 0.09 (A). In Dorper sheep, only the GG genotype was found. While not statistically significant (P>0.05), the GA genotype at GDF9:g.792G>A showed a trend toward increased litter size, indicating potential for Marker-Assisted Selection (MAS) in Local sheep.