In a past study, the team used specific-locus amplified fragment sequencing (SLAF sequencing) to detect single-nucleotide polymorphisms (SNPs) contributing to the differences in lambing numbers in Xinjiang sheep. This study verified the correlation between the COIL gene and lambing number characters in sheep and explored its possible mechanism of action. In this study, three SNPs in the COIL gene, namely COILSNP1 (rs7321466), COILSNP2 (rs7314134), and COILSNP3 (rs7321563), were explored in terms of their possible mechanism of action. A tissue expression profiling analysis revealed that the COIL gene was significantly more expressed in the uterus and ovaries than in other tissues (p < 0.05), whereas an association analysis revealed that the number of lambs born was significantly different among individuals with different genotypes of this COILSNP1 (p < 0.05). The Cell Counting Kit-8(CCK-8) revealed that the overexpression of the COIL gene significantly increased the proliferation of mouse ovarian fibroblasts and sheep fibroblasts (p < 0.05). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) revealed that the overexpression of the COIL gene significantly increased the activity of sheep fibroblasts (p < 0.01) and mouse ovarian fibroblasts (p < 0.05). The overexpression of the COIL gene affected the biogenesis pathway of spliceosomal U snRNPs by validating protein network connections. This activity affects ovulation, embryonic development, and changes in lambing size in sheep.
Keywords: COIL gene; association analysis; lambing number trait; single-nucleotide polymorphism.