Effects of High-fat Diet on Alternative Splicing of RNA in Abdominal Fat and Liver Tissues of Broilers

Abstract

【Objective】Excessive deposition of abdominal fat reduces disease resistance and slaughter rate of broilers. RNA alternative splicing is an important regulatory modality that affects gene function. Systematic analysis of RNA alternative splicing events during broiler abdominal fat deposition contributes to further understanding of the molecular regulation mechanism of broiler abdominal fat deposition.【Method】The transcriptome sequencing results of liver and abdominal fat tissues in high-fat-fed and normal-fed broilers were used to identify the differentially expressed and alternative spliced genes in abdominal fat and liver tissues during high-fat feeding. Significantly differentially spliced genes were analyzed by GO functional annotation, KEGG pathway enrichment analysis and Metascape enrichment analysis, and visualization processing was conducted for the significantly differential alternative splicing events, then splicing factors regulating these differential splicing events were analyzed.【Result】Transcriptome sequencing was performed on the abdominal fat and liver tissues of high-fat-fed broilers and normal-fed broilers. 233 significantly differentially expressed genes and 349 significantly differentially alternative spliced genes were found in the abdominal fat tissues. It was found that the significantly differential spliced genes were mainly enriched in cell proliferation, such as cell division and cell growth, as well as in pathways related to adipogenesis, such as glycerophospholipid metabolism and insulin signaling pathway. In liver tissues, 276 significantly differentially expressed genes and 224 significantly differential spliced genes were found, and the enrichment analysis of the significantly differential spliced genes revealed that these genes were mainly enriched in biological processes related to cellular metabolism such as protein acetylation, intra-protein amino acid acetylation and mRNA processing and also enriched in adipogenesis-related pathways such as insulin signaling pathway, glucagon signaling pathway and AMPK signaling pathway. Among the significantly differential spliced genes in abdominal fat and liver, a total of four candidate genes related to influencing abdominal fat deposition traits in broiler were screened, including GPAT4, RELCH, CYP39A1, and PPARA.【Conclusion】The results preliminarily revealed the patterns of RNA alternative splicing regulation in abdominal fat and liver tissues of broilers under high-fat feeding. It was inferred that high-fat feeding may lead to abdominal fat deposition in broilers by affecting the alternative splicing process of genes, which may activate the proliferation of preadipocytes and the metabolism of adipogenesis-related cells. Regulation of target genes by splicing factors was significantly involved in influencing the process of abdominal fat deposition in broilers.

Keywords

• xinghua broiler
• high-fat feed
• abdominal fat deposition
• transcriptome
• alternative splicing
• differentially expressed gene