Genes Regulation Analysis Of Gayal(Bos Frontalis) Meat Quality Traits Based On Transcriptome Sequencing

The Gayal(Bos frontalis)is a rare semi-wild and semi-domestic bovine species in China,with typical beef body shape and good meat production performance.Compared with other breeds of cattle,the Gayal has the characteristics of tender meat and low fat content.In order to explore the cause of the meat quality trait of the Gayal,we have used transcriptome sequencing technology to study the longissimus dorsi muscle of Gayal and Banna cattle.By means of Gene Ontology(GO)enrichment of biological functions,Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis and protein-protein interaction(PPI)network analysis,important genes and regulatory pathways in muscle tissue metabolism and meat quality traits expression were selected.The co-expression analysis has been performed on gene expression profiles.And the motif enrichment analysis has been performed on gene set modules with similar expression,whose results would be compared with the differential expressed genes.The bioinformatics method was used to study the transcriptional regulation of FOXA2 gene related to lipid metabolism.The specific research contents and results are as follows:1.Six hundred and thirty-eight differentially expressed genes were identified by differential expression analysis.Compared with Banna cattle,428 genes were up-regulated and 210 genes were down regulated in the longissimus dorsi muscle of Gayal.After GO,KEGG and PPI network analysis have been performed on differential expressed genes,it showed that Fox O signaling pathways,PI3K-Akt signaling pathwayas,as well as the related genes of myosin and actin,may be the main reasons for the fine diameter,high density and tender flesh of Gayal muscle fiber;THBS2 and ITGAV down-regulated in the longissimus dorsi muscle may cause the hardness of the intramuscular connective tissues in Gayal muscle to decrease;the combined effect of PPAR signaling pathway and fatty acid metabolism related genes is the main reason for the low fat content of Gayal muscle.2.By constructing gene co-expression network,the gene sets with similar expressions are divided into 28 modules.Motif enrichment analysis was performed on each module separately,and was related to the differentially expressed genes to screen out three differentially expressed transcription factors,FOXA2,NEUROG2 and RUNX1,which may have significant regulatory effects on genes in the four modules.3.Through analysis of FOXA2 gene expression regulation,the prediction of transcription factor binding sites in the promoter region indicated that transcription factors such as Sp1,GATA1,GATA2,CREB,C/EBPβ,E2F-1,and USF2 might play an importantrole in the expression of FOXA2 in the function of glycolipid metabolism and adipocyte differentiation.In summary,this study,which screened genes related to meat quality traits by transcriptome sequencing of gayal longissimus dorsi muscle,excavated transcription factors that affecting meat quality traits and searched the transcription level regulation of gene expression,can provide ideas for the research of molecular mechanism of muscle tissue development and the breeding of improving beef quality.