Functional genomics analysis of Leptin-Melanocortin system genes reveals candidate genes associated rapid growth and high carcass yield in sheep

Abstract

The Leptin-Melanocortin System (LMS) is an important regulatory system involved in appetite and energy balance in many organisms, including sheep. Functional genomics analysis of LMS genes can provide insights into the genetic factors that influence rapid growth and high carcass yield in sheep. However, the genetic potential of sheep growth and reproduction has not been fully exploited. Therefore, identifying genes that regulate growth and reproduction would offer strategies for improving the yield and quality of sheep meat. In this study, to explore the possible molecular mechanisms underlying rapid growth and muscular high-yield carcass in sheep, we screened 14 genes, which were previously claimed to be associated with such traits in humans and rodents. The FST outlier approach implemented in LOSITAN detected the loci under selection. These candidate genes were connected to complicated biological processes, including the regulation of eating behavior, energy balance, and the positive regulation of the cAMP biosynthetic process, according to the gene ontology (GO) study. In addition, the 14 genes' re-sequence data revealed 7,226 SNPs. The MC4R, STAT3, BDNF, and TUB genes were discovered to be an outlier and significantly under positive selection using the fixation index (FST) based technique with the tentative combined allocation of mean heterozygosity and FST. Differentially expressed genes were found, and their functions were assigned using a functional genomics approach. Results showed that these genes are crucial in determining sheep features including size and meat quality. Insights are gained into the molecular mechanisms behind these phenotypic variations, and possible genes for future sheep breeding initiatives are provided. This research proves the value of functional genomics analysis in identifying the heritable components of valuable sheep agriculture traits.