Transcriptomic and lipidomic analysis reveal hepatic metabolic disorders associated with ovarian regression in late-laying ducks

The liver serves as vital metabolic organ that mediates lipid biosynthesis and coordinates systemic lipid metabolism. However, the molecular alterations in hepatic lipid metabolism correlated with ovarian regression in the late-laying ducks are poorly understood. In this study, we combined hepatic histopathological examination, serum biochemical profiling, transcriptome and lipidome to investigate the differences in hepatic lipid metabolism and related genes between egg-laying (LLP) and ceased-laying (CLP) ducks. Our data showed that the liver index was significantly higher in CLP ducks than in LLP ducks. CLP duck livers exhibited greater inflammatory cell infiltration and lipid droplet accumulation, accompanied by elevated aspartate aminotransferase (AST), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels than LLP ducks. Hepatic transcriptomic analysis indicated that differentially expressed genes (DEGs) were mainly enriched in adipocytokine signaling pathway, PPAR signaling pathway, insulin signaling pathway, and steroid hormone biosynthesis. Additionally, lipidomic analysis further demonstrated the differential lipids were primarily classified into glycerophospholipids (GP), glycerolipids (GL), sphingolipids (SP), and fatty acyls (FA). Integrated multi-omics analysis revealed that adipocytokine signaling pathway, arachidonic acid metabolism, glycerophospholipid metabolism, and glycerolipid metabolism coordinated changes alongside divergent hepatic lipid profiles in the late-laying ducks. Taken together, the identified differentially expressed genes and lipid metabolites are correlated with modified hepatic lipid status concurrent with ovarian regression.