Transcriptome Analysis of a Bovine Mammary Epithelial Cell Model with Different Milk Fat Synthesis Capacity

Synthesis of milk fat is a complex biochemical process regulated by a series of molecular events. To determine gene expression changes during milk fat synthesis in bovine mammary epithelial cells, we established a cell model with a high capacity for milk fat synthesis using stimulation with acetate and ß-hydroxybutyrate. RNA sequencing was used to identify differentially expressed genes (DEGs) between the high-milk-fat and control cells. A total of 625 DEGs (358 upregulated, 267 downregulated) were identified. Among the highly expressed genes, there was enrichment for terms associated with fatty acid synthesis, activation, and triacylglycerol synthesis, consistent with active milk fat synthesis. Kyoto Encyclopedia of Genes and Genomes analysis suggested that DEGs were most enriched in the “lipid metabolism” subcategory of the “metabolism” category, and in the “signal transduction” subcategory of the “environmental information processing” category. Although an in vitro cell model cannot completely simulate in vivo lactation, it eliminates interference from other cell types and from the synthesis of other milk components during transcriptome profile analysis. This work provides a profile of gene expression changes that occur during milk fat synthesis in bovine mammary epithelial cells, which furthers our understanding of the molecular regulation of lipid metabolism. Overall design: 3 from high-milk-fat samples and 3 from control samples