Diacylglyceroltransferase-1 (DGAT1) expresses in nearly all tissues, including 
the mammary gland. Mice lacking DGAT1 exhibit decreased triglyceride content in 
mammary tissue, and are resistant to diet-induced obesity and diabetes mellitus. 
Thus, DGAT1 has received considerable attention. In the present study, the 
function of DGAT1 was examined by liposome mediated RNA interference (RNAi) to 
knockdown the expression of endogenous DGAT1 expression in bovine mammary 
epithelial cells (BMEC) and the changes of the biological functions of cells 
were analyzed. The mRNA and protein levels, intracellular triglyceride (TG) 
content, and total protein of BMECs were analyzed by real-time PCR, Western 
blot, TG kit, and ultraviolet spectrophotometer, respectively, before and after 
RNAi treatment. The results indicated that knockdown of DGAT1 expression 
significantly reduced TG content in BMECs. This study further confirmed the 
importance of DGAT1 in triglyceride synthesis in bovine mammary tissue.