Screening And Expression Analysis Of Intramuscular Fat Candidate Genes In Yanbian Yellow Cattle Based On RNA-seq

This experiment selected Yanbian yellow cattle as the research object.Using the RNA-seq technique to sequence the longissimus dorsi in high fat and low fat groups.Gene expression profiles were constructed and differentially expressed genes were obtained.GO functional annotation and pathway pathway analysis of differential genes,The differentially expressed genes were verified by qRT-PCR.To find candidate genes and regulatory pathways related to meat quality traits.The expression patterns of the ATF3 gene and KCTD15 gene were analyzed.Study the effect of tissue expression and intramuscular fat deposition,Provides genetic data for Yanbian yellow beef regulation.The main results of this study are as follows:(1)By comparing the meat quality of Yanbian Yellow Cattle's high-fat and low-fat groups,The shear stress values in the low fat group were significantly higher than those in the high fat group(P<0.01).The moisture content in the low-fat group was significantly higher than that in the high-fat group(P<0.05).The comparison of carcass traits showed that the marble pattern of the low-fat group was significantly higher than that of the high-fat group(P<0.01).The area of ocular muscles in the low-fat group was significantly higher than high-fat(P<0.05).(2)There were 38 differential genes between the high-fat and low-fat groups,of which there were 25 up-regulated genes and 13 down-regulated genes.GO analysis results showed that 38 genes were found in the Biological process,38 genes were in the cellular component,and 28 genes were found in the Molecular Function annotation.The KEGG pathway analysis was performed on the differentially expressed genes of the longissimus dorsi muscle in Yanbian yellow cattle's high-fat and low-fat groups.There are 269 pathways,The pathways involved in fat metabolism mainly include fatty acid biosynthesis,PPAR signaling pathway,Wnt signaling pathway,ECM-receptor interaction and focal adhesions(Focal adhesion)etc.(3)Select 4 differentially expressed genes and 2 non-differentially expressed genes,Up-regulated genes are ATF3 and KCTD15,down-regulated genes are MYOD1 and COL3A1,and non-differentially expressed genes are GPAM and FABP3 genes.Verified by fluorescence quantitative PCR test,The results showed that the level of gene expression verified by real-time PCR was consistent with the level of gene expression obtained from RNA-seq sequencing.This shows that the RNA-seq sequencing results are reliable.(4)ATF3 and KCTD15 genes were selected from differentially expressed genes for tissue expression analysis.It was found that the ATF3 gene was expressed in all 7 tissues of Yanbian yellow cattle,and the adipose tissue was significantly higher than other tissues(P<0.01).KCTD15 gene was expressed in 7 tissues of Yanbian yellow cattle,and the adipose tissue was significantly higher than other tissues(P<0.01).In muscle tissue,the expression level of ATF3 gene was significantly and positively correlated with IMF content(P<0.01),KCTD15 gene expression was not related to IMF content.