Screening of Key Genes Regulating Abdominal Fat Deposition in Qiandongnan Xiaoxiang Chickens Using Transcriptome Sequencing

This study intended to identify key functional genes that regulate abdominal fat weight in Qiandongnan Xiaoxiang chickens, thirty experimental individuals were selected and categorized into high abdominal fat (HAF, n=4) and low abdominal fat (LAF, n=4) groups based on their abdominal fat rate, whole blood samples harvested from both groups underwent transcriptome sequencing, and multiple analytical approaches including DESeq2-based differential expression analysis, protein-protein interaction (PPI) network analysis and gene module analysis were adopted to screen genes associated with abdominal fat deposition, with RT-qPCR further applied on an independent chicken population to validate the expression patterns of candidate genes; a total of 349 differentially expressed genes (DEGs) were found between the two groups, with 163 upregulated and 186 downregulated in the HAF group, integrated bioinformatics analyses of PPI networks and gene modules identified five candidate genes closely related to chicken abdominal fat deposition: glutamic-pyruvic transaminase 2 (GPT2), long-chain acyl-CoA synthetase 6 (ACSL6), threonine synthase-like 2 (THNSL2), carbamoyl-phosphate synthetase 1 (CPS1), and syndecan 3 (SDC3), and follow-up RT-qPCR tests confirmed that abdominal fat tissue exhibited significantly elevated SDC3 expression in the HAF group (P<0.05); overall, SDC3 is a critical gene that accelerates abdominal fat accumulation in Qiandongnan Xiaoxiang chickens and holds great potential as a molecular candidate gene for selective breeding to manipulate abdominal fat deposition traits in broilers.