Identification and functional analysis of m6A in the mammary gland tissues of dairy goats at the early and peak lactation stages

In this study, m6A-modified Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptome sequencing (RNA-seq) were used to identify the key genes with m6A modification during mammary gland development and lactation in dairy goats. The results showed that m6A methylation occurred at 3,927 loci, which were significantly enriched in the 3' untranslated coding region(3’UTR) and the termination codon region. In the early stage (E) and peak stage (P) of lactation, m6A methylation occurred extensively in mammary tissues, and a total of 725 differentially expressed m6A-modified genes were obtained, all negatively correlated with mRNA expression. In addition, gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that different methylated genes were mainly involved in the growth and apoptosis of mammary epithelial cells through signaling pathways related to mammary gland development and lactation, such as the mitogen-activated protein kinase (MAPK) and phospholipase D pathways. The aim of this study was to explore differentially expressed m6A-methylated genes in the mammary gland tissues of Laoshan dairy goats during the early and peak lactation stages through Methylated RNA immunoprecipitation sequencing (MeRIP-Seq) and to analyze the mechanism of regulation of the development and lactation of mammary gland tissue in the early and peak lactation stages in dairy goats.