Genetic Polymorphism and mRNA Expression Studies Reveal IL6R and LEPR Gene Associations with Reproductive Traits in Chinese Holsteins

Genetic selection of milk yield traits alters the energy distribution high producing cows, resulting in gene-induced negative balance, and consequently, poor body condition scores reduced reproductive performances. Here, we investigated two metabolic-syndrome pathway genes, IL6R (Interleukin 6 receptor) LEPR (Leptin receptor), for their polymorphism effects on performance dairy by applying association analyses 1588 Chinese Holstein cows (at population level) gene expression granulosa cells isolated from eight cell level). Among six single nucleotide polymorphisms examined (two SNPs four LEPR), five were significantly associated with at least one trait, including female fertility covering both ability to recycle after calving conceive keep pregnancy when inseminated properly, as well traits. Notably, identified variant SNP g.80143337A/C is a missense variant. The role cattle reproduction further confirmed observed differences relative levels amongst different developmental stages. Collectively, functional validation performed this study improved our understanding while providing important molecular markers genetic high-yielding cattle.