Transcriptomic and Lipidomic Characteristics of Subcutaneous Fat Deposition in Small-Sized Meat Ducks

<b>Background:</b> Subcutaneous fat deposition is associated with ducks' meat quality and the methods used to cook them. However, the reasons underlying the differences in the lipid deposition of small-sized Wuqin10 meat ducks remain unclear. <b>Method:</b> In the present study, to elucidate the metabolic mechanisms of lipid deposition, we comprehensively analyzed the transcriptomics and lipidomics of subcutaneous fat in Wuqin10 meat ducks with different subcutaneous thicknesses with six replicates. <b>Results:</b> A total of 1120 lipids were detected in the lipidomic analysis, and 39 lipids were inexorably regulated in the ducks with the thick subcutaneous layer compared to those with the thin layer; further, the up-regulated lipids were primarily triglycerides (TGs), which may have resulted in adipocyte enlargement. Furthermore, the transcriptomic analysis identified 265 differentially expressed genes (DEGs), including 119 down-regulated and 146 up-regulated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the DEGs were significantly enriched in the histidine, arginine, proline metabolism signaling and adipocytokine signaling pathways. The protein-protein interaction (PPI) network in Cytoscape 3.8.2 identified hub genes HSP90AA1, RUNX2, ACTN2, ACTA1, IL10, CXCR4, EGF, SOCS3 and PTK2, which were associated with the JAK-STAT signaling pathway and regulation of adipocyte hypertrophy. <b>Conclusion:</b> Taken together, our findings reveal the patterns of lipids and the gene expression of subcutaneous fat, providing a basis for future studies of subcutaneous fat deposition in small-sized meat ducks.