Identification of Candidate Genes that Specifically Regulate Subcutaneous and Intramuscular Fat Deposition Using Transcriptomic and Proteomic Profiles in Dingyuan Pigs

Abstract Background: Subcutaneous fat and intramuscular fat (IMF) deposition are closely related to meat production and pork quality. The Dingyuan pig is a local pig breed in Anhui Province, China, that has great potential for fat deposition. Individuals with extreme subcutaneous fat and intramuscular fat content can be found in this breed, which provides a good study system for investigating the molecular mechanisms regulating these two types of fat deposit.Results: In this study, we used RNA-Seq and tandem mass tags-based proteomics to analyze the key pathways and genes that specifically regulate subcutaneous fat and intramuscular fat deposition in Dingyuan pigs. We identified 191 differentially expressed genes (DEGs) and 61 differentially abundant proteins (DAPs) in the high backfat thickness (HBF) and low backfat thickness (LBF) groups. In the high intramuscular fat and low intramuscular fat groups, we found 85 DEGs and 12 DAPs. The gene ontology and KEGG pathway enrichment analysis showed that the DEGs and DAPs in the backfat groups were mainly involved in various metabolic pathways, such as those related to carbohydrates, amino acids, esters, and fatty acids, whereas the DEGs and DAPs of the IMF groups were involved in a wide range of signaling pathways, including metabolic pathways, the insulin pathway, ketone body synthesis and degradation, longevity, and some disease-related pathways. Among the genes related to the metabolic pathways of carbohydrates, amino acids, esters, and fatty acids, we found 26 candidate genes that specifically regulate subcutaneous fat deposition and 7 genes that specifically regulate IMF deposition in Dingyuan pigs.Conclusion: Our data show that subcutaneous fat deposition and IMF deposition are regulated by the same genes, but there are also genes that specifically regulate these two fat depositions. Our data provide insights into the mechanisms of pig fat deposition.