Gene Expression Profiling of Adipose Tissue in Enshi Black Pigs Subjected to Cold Stress

To investigate the response mechanism of cold-resistant Enshi black pig breeds under cold stress, nine Enshi black pigs were randomly divided into three groups with three pigs in each: a control group (18 ± 2 °C for 58 d), a cold-stress-acclimated group (3 to 8 °C to -17 to -21 °C for 58 d), and an acute cold stress group (-17 to -21 °C for 3 d). RNA-seq technology was used to analyze mRNA and lncRNA expression patterns in subcutaneous adipose tissue under cold stress. The results showed that, under acute cold stress, many metabolic pathways were activated, including those involved in rapid energy supply (e.g., the citric acid cycle/TCA cycle, fatty acid degradation and metabolism, and glycolysis/gluconeogenesis), signal transduction pathways (e.g., PI3K Akt, MAPK, PPAR, HIF-1, mTOR, and FoxO), and immune and cellular homeostasis pathways (chemokine signaling pathway, T cell receptor signaling, Toll-like receptor signaling, and apoptosis and autophagy regulation). Under cold stress acclimation, metabolic regulatory pathways (e.g., AMPK, mTOR, FoxO, HIF-1, glycolysis/gluconeogenesis, and fatty acid degradation), immune and inflammatory regulatory pathways (Toll-like receptors, NOD like receptors, and T/B cell receptor signaling pathways), and signal transduction and cell homeostasis pathways (MAPK, PI3K Akt, NF-κB, Notch signaling pathways, apoptosis, and autophagy regulation) were continuously activated to ensure the stability of adipose tissue structure and function. Acute cold stress activated more pathways than cold stress acclimation, but both led to significant changes in energy metabolism. The results identified the molecular regulatory mechanisms of adipose tissue under cold stress, providing a basis for the subsequent breeding of new cold-resistant pig breeds.