Screening and analysis of genes related to lipid metabolism of longissimus dorsi muscle of ovary-removed Zangjiang sows based on transcriptome sequencing

【Objective】 This paper investigated the dynamic regulation of fat deposition in longissimus dorsi muscle of ovary-removed Zangjiang sows,to provide theoretical basis for revealing the regulatory mechanism of fat deposition.【Method】 The ovaries of Zangjiang sows were surgically removed at 45 days of age(treatment group),with the control group of Zangjiang sows being traumatized in the same area of the abdomen without removing ovaries. The variation of serum estrogen,triglyceride and total cholesterol contents of Zangjiang sows were recorded at 45,154 and 300 days of age respectively. The longissimus dorsi muscle tissue samples were collected at 300 days of age for paraffin sectioning and sequencing by Illumina NovaSeq 6000 sequencing platform. The differentially expressed genes(DEGs)in the longissimus dorsi muscle tissues were screened by DESeq2 with|log₂ Fold Change|>1 and P<0.05. The GO and KEGG databases were used for GO functional annotation analysis and KEGG signaling pathway enrichment analysis respectively,to identify genes that might be involved in lipid metabolism. The transcriptome sequencing results were verified by real-time fluorescence quantitative PCR.【Result】 The serum triglyceride content of Zangjiang sows in the treatment group was significantly higher than that of the control group(P<0.05,the same below),the total cholesterol content was extremely significantly higher than that of the control group(P<0.01,the same below),the estrogen content was extremely significantly lower than that of the control group,and the total fat content of longissimus dorsi muscle was significantly lower than that of the control group. There were 278 DEGs between the treatment group and control group of Zangjiang sows,of which 33 DEGs were related to lipid metabolism. The DEGs were mainly annotated on the GO function entries of bile acid secretion,phosphatidylinositol 3-kinase signaling,protein kinase B signaling,G protein-coupled receptor binding,glycosaminoglycan binding,chemokine activity and chemokine receptor binding. And they were mainly enriched in KEGG signaling pathways including glycolysis/gluconeogenesis,starch and sucrose metabolism,carbohydrate digestion and uptake, MAP kinase serine/threonine phosphatase activity,estrogen 2-hydroxylase activity and cGMP-PKG signaling. The expression trend of the target genes detected by real-time fluorescence quantitative PCR was basically consistent with the transcriptome sequencing results,indicating that the transcriptome sequencing data were reliable.【Conclusion】 Decreased serum estrogen levels,increased triglyceride and total cholesterol levels,and decreased intermuscular fat content of longissimus dorsi muscle in ovary-removed Zangjiang sows are associated with differential expression of 33 DEGs involved in lipid metabolism regulation,including CALML5,PLCZ1,PIK3C2G,and IL6,and are involved in function terms such as bile acid secretion,phosphatidylinositol 3-kinase signaling regulation,and involved in signaling pathways such as glycolysis/gluconeogenesis, starch and sucrose metabolism.