Molecular characterization of fecundity-related gene regions in some of Türkiye's native sheep breeds

Abstract

In this study, the BMP15 and GDF9 gene regions were examined through DNA sequencing in some native sheep breeds of Turkiye (Kivircik, Karacabey Merino, Chios, Gokceada, cine capari, Awassi, and Karakacan). In the BMP15 exon 2 region, two single nucleotide polymorphisms (SNPs) were identified: one synonymous SNP, P248P (proline/proline), and one nonsynonymous SNP, L251P (leucine/proline), resulting in a missense mutation. In the GDF9 exon 1 region, only a nonsynonymous SNP, R87H (histidine/ arginine), was found. In the GDF9 exon 2 region, four SNPs were identified: two nonsynonymous SNPs, E241K (glutamate/lysine) and V332I (valine/isoleucine), and two synonymous SNPs, L159L (leucine/leucine) and E326E (glutamate/glutamate). The identified haplotypes in the GDF9 gene region showed a high D' (linkage disequilibrium) value, indicating a strong association. Furthermore, a complete correlation was observed between the E326E and V332I variants in the studied breeds. The Chios breed exhibited significantly higher frequencies of heterozygosity for the E326E and V332I variants compared to the Kivircik and Karacabey Merino breeds. The heterozygosity frequencies for the E326E and V332I variants in the Kivircik, Karacabey Merino, and Chios breeds were determined to be 0.08, 0.13, and 0.46, respectively. The higher frequency of heterozygosity observed in E326E and V332I variants within the Chios breed suggests their association with the trait of multiple births.