Screening Of Key Genes For Perirenal Fat Deposition In Angus Cattle And Simmental Cattle And Comparison Of Related Lipid Metabolites

In order to explore the effect of lipid metabolite concentration on perirenal fat deposition in Angus cattle and Simmental cattle and screen out the key candidate genes of perirenal fat deposition in Angus cattle and Simmental cattle.Angus bulls and Simmental bulls with similar age and body condition in the late fattening period were selected as the research objects.They were fed to the slaughter weight and slaughtered under the same management feeding conditions.By comparing the carcass traits and visceral fat deposition of the two breeds of cattle,analyzing the effects of related lipid metabolite concentrations on fat deposition and transcriptome sequencing technology,the differentially expressed genes of perirenal fat deposition in Angus cattle and Simmental cattle were screened out,which provided a basic theory for subsequent Angus cattle meat quality improvement and molecular breeding.The specific test results are as follows :1.Comparative study on production performance,slaughter performance and visceral fat deposition of Angus and Simmental cattleIn terms of production performance : Angus cattle were significantly higher than Simmental cattle in daily weight gain(P<0.01);the feed weight ratio of Simmental cattle was significantly higher than that of Angus cattle(P<0.01).In terms of slaughter performance:The slaughter rates of Angus cattle and Simmental cattle were 60.08 % and57.38 %,respectively,and there was no significant difference between the groups(P>0.05);The meat-bone ratio and eye muscle area of Angus cattle were significantly higher than those of Simmental cattle(P>0.05);The fat thickness was significantly higher than that of Simmental cattle(P<0.01).Visceral fat deposition: Angus cattle deposited more fat around their kidneys than Simmental cattle(P<0.05).2.The effect of related lipid metabolism on perirenal fat deposition in Angus and Simmental cattleThe concentration of lipid metabolites in serum : the concentration of triglyceride(TG)and leptin(LEP)in serum of Angus cattle was significantly higher than that of Simmental cattle(P<0.05).TP concentration was significantly lower than that of Simmental cattle(P<0.05).The activities of fatty acid synthase(FAS)and diacylglycerol acyltransferase 1(DGAT-1)in liver of Angus cattle were significantly higher than those of Simmental cattle(P<0.01).The activity of related lipid metabolism enzymes in perirenal fat : The concentration of FAS in perirenal fat of Angus cattle was significantly higher than that of Simmental cattle(P<0.05),and the concentration of LPL was significantly lower than that of Simmental cattle(P<0.01).3.Screening and differential analysis of key genes for renal fat deposition in Angus cattle and Simmental cattleThe transcriptome sequencing data of 6 kidney fat samples and 6 liver tissues were obtained by Illumina Nova Seq 6000 platform.The results showed that the average alignment rate of the samples to the genome was more than 90 %,which met the subsequent experimental analysis.GO functional classification annotated 2842 differentially expressed genes in biological processes,of which 1278 DEGs were enriched in biological processes,1017 DEGs were enriched in cellular components,and 547 DEGs were enriched in molecular functions.KEGG pathway analysis showed that 6 pathways(ECM-receptor interaction pathway,PPAR signaling pathway,fatty acid degradation,steroid hormone biosynthesis,pentose and glucuronate conversion and peroxidase)related to fat metabolism were significantly enriched in different tissues of the two breeds.According to GO functional annotation and KEGG enrichment,30 highly expressed common genes were screened,and10 genes related to fat deposition were screened in kidney fat and liver : FABP4、LPL、PLIN1、PIK3R1、SCD、COL1A1、LPIN1、ACADL、ACSL1 and CPT1 A.To verify the accuracy of transcriptome data,q RT-PCR verification of differentially expressed genes showed that the expression pattern of differentially expressed genes was consistent with transcriptome,indicating that the expression level of RNA-seq was reliable.In summary,the perirenal fat deposition ability of Angus cattle is better than that of Simmental cattle.The activity of FAS and LPL in the liver regulates the concentration of TG and LEP in serum,which plays a key role in the deposition of perirenal fat in Angus cattle.Ten candidate genes related to perirenal fat deposition were screened by transcriptome sequencing : FABP4,LPL,PLIN1,PIK3R1,SCD,COL1A1,LPIN1,ACADL,ACSL1 and CPT1A.