Transcriptome Analysis of Mammary Gland Tissue to Identify Major Genes Involved in the Milk Production

Milk production is one of the most important economic traits in the dairy cattle industry, which is controlled by a large number of genes and is a function of the activity of epithelial cells that are influenced by several biological pathways and the interaction of different genes and gene expression. Gene expression is a process in which information within a gene is used to obtain a functional product. It is also one of the fundamental issues that helps the genotype to appear as a phenotype. The aim of this study was to identify the genes affecting milk production and to construct the gene interaction network of the studied genes to identify the major genes of the effect to better understand the mechanism of milk production using the gene expression pattern during bioinformatics studies. in this study, in order to identify genes with different expression in dairy cow breast tissue, gene expression data related to breast tissue with access number GSE33680 were download from the GEO section of the NCBI database. Data quality was assessed using the limma package available in R software and the basic component analysis method. DAVID software was used to evaluate the function of genes with different expression. After identifying the target genes, they were presented to STRING databases. Cytoscape software was used to explain the role of genes. In this study, the results of analysis of gene expression differences led to the identification of 14020 genes, which according to fold change and adj P-Value statistics, 409 gene increased expression and 326 genes decreased expression. Among the known biological pathways affecting milk production are NF-KB signaling, Glycerolipid metabolism, EGFR1, IL6, B cell receptor. The most important genes are based on the degree of association with other genes and the internal and external centrality of MYC, KRAS, HSPA8, ATP5B, SRC, JAK1 and FOXA2 genes, which play a role in regulating milk production in several reports.