Polymorphisms of PRKAA1 and FABP4 genes and their association with feed efficiency in Hu sheep

Feed efficiency (FE) is an important economic trait in the sheep industry, influenced by biological processes such as digestion and metabolism. PRKAA1 gene participates in the synthesis and oxidation of fatty acids; the FABP4 gene is closely associated with intracellular fatty acid regulation. In this study, we use Sanger sequencing, KASPar genotyping, and qRT-PCR to investigate the association between variations in PRKAA1 and FABP4 genes and feed efficiency in Hu sheep, the expression patterns of PRKAA1 and FABP4 genes in different tissues, as well as the differences in expression of different genotypes in tail fat. The association analysis results indicated that PRKAA1 gene g.35431965 C > T locus and FABP4 gene g.62829807 C > T locus were significantly associated with the feed conversion ratio (FCR) of Hu sheep aged 80–180 days, with the dominant genotypes being CC and CC, respectively. Simultaneously, there existed notable disparities among various genotype combinations. The qRT-PCR results showed PRKAA1 and FABP4 genes were widely expressed in ten tissues, of which the PRKAA1 gene was lower expression level in rumen and lung, FABP4 gene was significantly highest expression in the tail fat than the other tissues; the expression of two different genotypes in tail fat also exhibits significant differences (P ≤ 0.05). Therefore, these findings suggested that the variation of PRKAA1 and FABP4 genes might be used as novel genetic marker for improving feed efficiency in sheep.