The role of RORA (RAR-Related Orphan Receptor Alpha) receptors, one of the candidate genes identified for sheep reproductive traits, in sheep reproduction

RORA (RAR-Related Orphan Receptor Alpha) regulates estrogen synthesis by transcribing steroid related genes. Litter size is an important reproductive trait associated with estrogen synthesis. Therefore, it is critical to investigate the relationship between the RORA gene and sheep litter size. In this study, a 23 base pair nucleotide sequence mutation in a gene called RORA and the effect of this mutation on the productivity of sheep offspring were investigated. In this study, a 23 bp nucleotide sequence mutation was found in intron 1 of the RORA gene in 35 female Bafra ewes. Ten ml of milk was collected from each of the 35 samples. The litter size of the DD genotype was significantly higher than the ID genotype and the II genotype in the second born litter size (p> 0.05). The relationship between combined genotypes and average litter size showed that ewes with homozygous (DD) genotype had larger lambs than ewes with heterozygous (ID) genotype. Multiple pregnancy rates in the first and second litters were higher than the average stillbirth rate (p> 0.05). To summarize, this study provided theoretical references for further research on the function of RORA gene and breeding of Bafra sheep. The 23-bp indel variants can be used as molecular markers for the size of first and second born offspring of ewes in MAS (marker assisted selection) breeding.