Comparative analysis of the hypothalamus transcriptome of laying ducks with different residual feeding intake

Abstract

Feed costs account for approximately 60-70% of the cost of poultry farming, and feed utilization is closely related to the profitability of the poultry industry. To understand the causes of the differences in feeding in Shan Partridge ducks, we compared the hypothalamus transcriptome profiles of two groups of ducks using RNA-seq. The two groups were: 1) low residual feed intake (LRFI) group with low feed intake but high feed efficiency, and 2) high residual feed intake (HRFI) group with high feed intake but low feed efficiency. We found 78 DEGs were enriched in nine differential Kyoto Encyclopedia of Genes and Genome (KEGG) pathways, including neuroactive ligand-receptor interaction, GABAergic synapse, nitrogen metabolism, cAMP signaling pathway, calcium signaling pathway, nitrogen metabolism, tyrosine metabolism, ovarian steroidogenesis, and gluconeogenesis. To further identify core genes among the 78 DEGs, we performed protein-protein interaction and co-expression network analyses. After comprehensive analysis and experimental validation, four core genes, namely, glucagon (GCG), cholecystokinin (CCK), gamma-aminobutyric acid type A receptor subunit delta (GABRD), and gamma-aminobutyric acid type A receptor subunit beta1 (GABRB1), were identified as potential core genes responsible for the difference in residual feeding intake between the two breeds. We also investigated the level of cholecystokinin (CCK), neuropeptide Y (NPY), peptide YY(PYY), ghrelin, and glucagon-like peptide1 (GLP-1) hormones in the sera of Shan Partridge ducks at different feeding levels and found that there was a difference between the two groups with respect to GLP-1 and NPY levels. The findings will serve as a reference for future research on the feeding efficiency of Shan Partridge ducks and assist in promoting their genetic breeding.