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

As a result of the studies, it has been determined that genes such as Bone Morphogenetic Protein Gene 15 (BMP15) and Growth Differentiation Factor 9 (GDF9) are associated with multiple births (fecundity) in some sheep breeds. In this study, BMP15 gene regions in some domestic sheep breeds (Kivircik, Karacabey Merino, Chios, Gökceada, Cine Capari, Awassi and Karakaçan breeds) and GDF9 (Kivircik, Karacabey Merino and Chios breeds) were investigated by DNA sequencing. A Single Nucleotide Polymorphism (SNP) was detected at two different points in the BMP15 Exon2 region, one non-amino acid replacement (synonymous), P248P (Proline/Proline) and one amino acid replacement (non-synonymous), L251P (Leucine/Proline). A total of 5 SNPs were detected in the GDF9 gene; a non-synonymous, R87H (Histidine/Arginine) in GDF9 Exon1, two non-synonymous, E241K (Glutamate/Lysine) and V332I (Valine/Isoleucine) and two synonymous, L159L (Leucine/Leucine) and E326E (Glutamate/Glutamate) in GDF9 Exon2 region. It has been determined that haplotypes structured with SNPs in the GDF9 gene region have high D' (linkage disequilibrium) value and E326E and V332I variants have a perfect positive correlation in the studies breeds. Heterozygous frequencies of E326E and V332I variants were found to be approximately three times higher in Chios breeds compared to Kivircik and Karacabey Merino breeds. E326E and V332I variants of the Chios breed showed a higher frequency of heterozygosity compared to other breeds, suggesting that these variants can be associated with multiple births, and it is recommended to focus on these variants in future studies.