宁乡猪不同发育阶段肌内脂肪沉积差异表达基因及其调控通路分析

Analysis of Differentially Expressed Genes and Regulatory Pathways in Intramuscular Fat Deposition of Ningxiang Pigs at Different Developmental Stages

【目的】分析不同日龄宁乡猪背最长肌组织mRNA表达谱,筛选发育过程中与脂肪沉积相关的差异表达基因及其所参与的信号通路,并确定部分关键基因在肌内脂肪发育过程中的表达特征。【方法】选取30(D30)和250(D250)日龄宁乡猪各3头,采集背最长肌组织样品提取总RNA进行转录组测序,对测序数据进行比对和处理,筛选参与脂质代谢的差异表达基因进行GO功能、KEGG通路及蛋白互作分析,并随机选取6个差异表达基因进行实时荧光定量PCR验证。【结果】共筛选出30个与脂质代谢相关的差异表达基因,其中9个上调,21个下调。差异表达基因主要富集在脂肪酸氧化、长链脂肪酸代谢等生物过程,线粒体、细胞器膜等细胞组分,酰甘油O-酰基转移酶活性、氧化还原酶活性等分子功能;参与了脂肪酸降解、甘油酯代谢、PPAR等信号通路。蛋白互作分析筛选出ACSL 1、ACAA 2、HADHB、LIPG、GPCPD 1、ALDH 2等关键蛋白基因处于核心位置,通过其mRNA表达量不同参与脂肪沉积调控。ACSL 1、CPT 1 A等6个基因的实时荧光定量PCR验证结果与转录组测序结果一致。【结论】ACSL 1、ACAA 2、HADHB、LIPG、GPCPD 1、ALDH 2等作为核心基因参与宁乡猪肌内脂肪调控,并通过脂肪酸降解、甘油酯代谢等信号通路发挥调控作用。本研究结果为进一步研究猪肌内脂肪沉积相关基因的分子调控机制提供了理论参考。

【Objective】This study was conducted to screen out differentially expressed genes(DEGs)and their regulatory signaling pathways related to lipid metabolism by analyzing mRNA expression profiles in longissimus dorsi muscle tissues of Ningxiang pigs at different ages,and determine the expression characteristics of some key genes during the development of intramuscular fat.【Method】Ningxiang pigs of 30(D30,n=3)and 250(D250,n=3)days old were selected,the longissimus dorsi muscle tissues were collected to extract total RNA for RNA-Seq,and sequencing data was compared and processed.The DEGs related to lipid metabolism were screened for GO function,KEGG pathway and protein interactions analysis.Six DEGs were randomly selected for Real-time quantitative PCR validation.【Result】A total of 30 DEGs related to lipid metabolism were screened by RNA-Seq,among which 9 genes were up-regulated and 21 genes were down-regulated.The DEGs were mainly enriched in biological process such as fatty acid oxidation and long-chain fatty acid metabolic process;Cellular components such as mitochondrion and organelle membrane;Molecular functions such as acylglycerol O-acy ltransferase activity and oxidoreductase activity.The DEGs were involved signaling pathway such as fatty acid degradation,glycerolipid metabolism and PPAR.Key protein genes such as ACSL 1,ACAA 2,HADHB,LIPG,GPCPD 1 and ALDH 2 were screened out by protein interaction analysis,which were involved in the regulation of lipid metabolism through their mRNA expression.Real-time quantitative PCR validation results of six genes such as ACSL 1 and CPT 1 A were consistent with RNA-Seq results.【Conclusion】This study screened some key genes such as ACSL 1,ACAA 2,HADHB,LIPG,GPCPD 1 and ALDH 2 participating in the regulation of intramuscular fat in Ningxiang pigs,and played a regulatory role through signaling pathways such as fatty acid degradation and glycerolipid metabolism.The resuts provided a theoretical reference for further research on the molecular regulation of genes related to intramuscular fat deposition in pigs.