Transcriptome Analysis of Adipose Tissue Indicates That the cAMP Signaling Pathway Affects the Feed Efficiency of Pigs.

Feed efficiency (FE) is one of the main factors that determine the production costs in the pig industry. In this study, RNA Sequencing (RNA-seq) was applied to identify genes and long intergenic non-coding RNAs (lincRNAs) that are differentially expressed (DE) in the adipose tissues of Yorkshire pigs with extremely high and low FE. In total, 147 annotated genes and 18 lincRNAs were identified as DE between high- and low-FE pigs. Seventeen DE lincRNAs were significantly correlated with 112 DE annotated genes at the transcriptional level. Gene ontology (GO) analysis revealed that DE genes were significantly associated with cyclic adenosine monophosphate (cAMP) metabolic process and Ca binding. cAMP, a second messenger has an important role in lipolysis, and its expression is influenced by Ca levels. In high-FE pigs, nine DE genes with Ca binding function, were down-regulated, whereas , which encodes calbindin D9K that serve as a Ca bumper, was up-regulated. Furthermore, , , and , which participate in the cAMP signaling pathway, were down-regulated in the upstream of lipolysis pathways. In high-FE pigs, the key genes involved in the lipid biosynthetic process ( and ), fatty acid oxidation ( and ), and lipid homeostasis ( and ) were down-regulated. These results suggested that cAMP was involved in the regulation on FE of pigs by affecting lipid metabolism in adipose tissues.