Abstract：In order to explore the hub genes for the difference of adipogenesis and lipid metabolism in dif-ferent tissues of Laiwu pigs, Laiwu pigs with similar body weight at 180 days of age were used to identify the mRNA expression profiles of intramuscular fat (IMF) and subcutaneous fat (SCF). The functions of diffe-rentially expressed mRNAs were analyzed through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). A protein-protein interaction (PPI) network of the top 300 mRNAs with a high average ex-pression level was constructed, key regulatory mRNAs were screened, and sequence features and protein structures of the key mRNAs were analyzed. Meantime, the reliability of the sequencing data was verified by real-time fluorescence quantitative PCR (qRT-PCR) for 6 randomly selected mRNAs. A total of 1 665 differen-tially expressed mRNAs were identified from IMF and SCF mRNA expression profiles, of which 888 were up-regulated and 777 were down-regulated. The GO results showed that the differentially expressed mRNAs were mainly involved in regulating signal pathways in biological process (BP); composing biological membranes in cellular component (CC); affecting the enzyme activity in the cell metabolism process in molecular function (MF). The KEGG enrichment results showed that the differentially expressed mRNAs were mainly involved in adipocyte production, lipid metabolism, inflammation and cancer-related signaling pathways. Through analysis of the PPI network, gene sequence and protein structure characteristics, it was found that C-X-C motif chemokine receptor 4 (CXCR4), platelet and endothelial cell adhesion molecule 1 (PECAM1), urokinase-type plasminogen activator (PLAU), angiotensinogen (AGT), AKT serine/threonine kinase 2 (AKT2), heat shock cognate 70-kD protein, tandem duplicate 2 (HSP70.2), galectin 3 (LGALS3), and periostin (POSTN) were in the center of the regulatory network. The qRT-PCR verification results were consistent with the sequencing results, proving the reliability of sequencing results. By comparing the difference between IMF and SCF tran-scriptomes, it was found that AGT, CXCR4, HSP70.2 and PLAU genes play critical roles in the lipid me-tabolism process of IMF deposition and can be used as candidate genes in IMF regulation.
