Abstract
As the primary site of lipogenesis in birds, the liver orchestrates avian lipid metabolism and is pivotal for fat accumulation in chickens. Lipid metabolism during the broiler embryo stage may significantly affect post-hatch growth performance, yet research on this subject remains limited. While long non-coding RNAs (lncRNAs) have been found to regulate liver lipid metabolism in post-hatch chickens, their functions during the embryonic stage remains unclear. This study revealed that, compared to lean line broiler embryos, fat line broiler embryos showed upregulated gene expression related to de novo fatty acid synthesis, glycerol-3-phosphate synthesis, triglyceride synthesis, and the degradation of both fatty acids and cholesterol. Through transcriptome analysis and functional validation, lncRNA1926 and lncRNA3223 were identified as key regulators of lipid metabolism in broiler embryo livers. Knocking down either of lncRNA1926 or lncRNA3223 significantly reduced lipid droplet accumulation, triglyceride levels, and total cholesterol levels in primary hepatocytes of broiler embryos. Our findings demonstrate distinct lipid metabolic gene expression profiles between fat and lean line broiler embryo livers, and highlight lncRNA1926 and lncRNA3223 are key regulators of lipid metabolism during the embryonic stage. This study enhances the scientific understanding of lipid metabolism regulation in chicken livers and provides a theoretical foundation for genetically improving abdominal fat traits in broilers.