Identification of central regulators associated with serum triglyceride metabolism during growth and development in...

Liver lipid metabolism is critical for chicken abdominal fat (AF) deposition, and serum triglyceride (TG) serves as an important indicator of lipid delivery from the liver to adipose tissue. However, the hepatic regulatory networks underlying serum TG metabolism during the growth and development of chickens remain poorly understood. In the present study, serum TG levels were measured in Wannan chickens at 9 W, 20 W, and 52 W. Liver transcriptome data from 24 Wannan chickens (n = 8 per stage) were analyzed using differential expression gene analysis, weighted gene co-expression network analysis (WGCNA), and Mfuzz clustering. Pearson correlation analysis revealed a strong positive association between TG content and abdominal fat percentage (AFP) (r = 0.777, p = 8.05 × 10⁻⁶). A total of 1048, 1407, and 234 differentially expressed genes (DEGs) were identified in the 9 W vs. 20 W, 9 W vs. 52 W, and 20 W vs. 52 W comparisons, respectively. WGCNA identified 58 co-expression modules, among which the plum2 module showed significant correlations with TG and AFP. Furthermore, several genes, including GPAM (glycerol-3-phosphate acyltransferase, mitochondrial), AGPAT2 (1-acyl-sn-glycerol-3-phosphate acyltransferase 2), MBOAT2 (membrane-bound O-acyltransferase domain containing 2), DHCR7 (7-dehydrocholesterol reductase), SQLE (squalene epoxidase), and SCD (stearyl CoA desaturase), involved in glycerolipid metabolism, steroid biosynthesis, and fatty acid metabolism, were identified as central regulators that contribute to the regulation of TG. These findings provide new insights into the hepatic regulatory mechanisms of lipid metabolism, which may inform breeding programs aiming to optimize AF in chickens.