Transcriptome Analysis Reveals the Early Development in Subcutaneous Adipose Tissue of Laiwu Piglets

Adipose tissue plays an important role in pig production efficiency. Studies have shown that postnatal development has a vital impact on adipose tissue; however, the mechanisms behind pig adipose tissue early-life programming remain unknown. In this study, we analyzed the transcriptomes of the subcutaneous adipose tissue (SAT) of 1-day and 21-day old Laiwu piglets. The results showed that the SAT of Laiwu piglets significantly increased from 1-day to 21-day, and transcriptome analysis showed that there were 2352 and 2596 differentially expressed genes (DEGs) between 1-day and 21-day SAT in male and female piglets, respectively. Expression of genes in glycolysis, gluconeogenesis, and glycogen metabolism such as pyruvate kinase M1/2 (<i>PKM</i>), phosphoenolpyruvate carboxy kinase 1 (<i>PCK1</i>) and amylo-alpha-1, 6-glucosidase, 4-alpha-glucanotransferase (<i>AGL</i>) were significantly different between 1-day and 21-day SAT. Genes in lipid uptake, synthesis and lipolysis such as lipase E (<i>LIPE</i>), acetyl-CoA carboxylase alpha (<i>ACACA</i>), Stearoyl-CoA desaturase (<i>SCD</i>), and 3-hydroxy-3-methylglutaryl-CoA synthase 1 (<i>HMGCS1</i>) were also differentially expressed. Functional analysis showed enrichment of DEGs in transcriptional regulation, protein metabolism and cellular signal transduction. The protein-protein interaction (PPI) networks of these DEGs were analyzed and potential hub genes in these pathways were identified, such as transcriptional factors forkhead box O4 (<i>FOXO4</i>), CCAAT enhancer binding protein beta (<i>CEBPB</i>) and CCAAT enhancer binding protein delta (<i>CEBPD</i>), signal kinases BUB1 mitotic checkpoint serine/threonine kinase (<i>BUB1</i>) and cyclin-dependent kinase 1 (<i>CDK1</i>), and proteostasis-related factors ubiquitin conjugating enzyme E2 C (<i>UBE2C</i>) and cathepsin D (<i>CTSD</i>). Moreover, we further analyzed the transcriptomes of SAT between genders and the results showed that there were 54 and 72 DEGs in 1-day and 21-day old SAT, respectively. Genes such as <i>KDM5D</i> and <i>KDM6C</i> showed gender-specific expression in 1-day and 21-day SAT. These results showed the significant changes in SAT between 1-day and 21-day in male and female Laiwu pigs, which would provide information to comprehensively understand the programming of adipose tissue early development and to regulate adipose tissue function.