Triacylglycerols (TAGs) are the primary form of energy storage in eukaryotes. They also serve as a reservoir of fatty acids for membrane biogenesis of the cells and lead to obesity when excessively accumulated in adipose tissues. Diacylglycerol acyltransferases (DGATs) are responsible for the final and rate-limiting step of TAG biosynthesis in eukaryotic organisms. Understanding the roles of DGATs will help to create transgenic plants and microbes with value-added properties and provide information for therapeutic intervention for obesity and related diseases. Mammalian DGATs are divided into DGAT1 and DGAT2 subfamilies. It was unclear which DGAT was the major isoform expressed in animals. The objective of this study was to identify the major form of DGATs expressed in animal cells and compared to those expressed in tung tree seeds. TaqMan and SYBR Green qPCR assays evaluated DGAT mRNA levels in mouse 3T3-L1 adipocytes and RAW264.7 macrophages and tung tree seeds. TaqMan qPCR showed that DGAT mRNA levels were stable during the time-course study, DGAT2 mRNA levels were 10–30 folds higher than DGAT1 in adipocytes and macrophages, and DGAT mRNA levels in adipocytes were 50–100 folds higher than those in macrophages. As a positive control, the anti-inflammatory tristetraprolin (TTP) mRNA levels were 2–4 folds higher in macrophages than those in adipocytes and similar to DGAT1 in adipocytes but 100-fold higher than DGAT1 in macrophages. SYBR Green qPCR analyses confirmed TaqMan qPCR results. DGAT2 mRNA as the major DGAT mRNA in mouse cells was similar to that in tung tree seeds where DGAT2 mRNA levels were 10–20-fold higher than DGAT1 or DGAT3. Our results conclusively demonstrated that DGAT2 mRNA was the major form of DGATs expressed in plant and animal cells. This finding should facilitate efforts to regulate lipid/oil accumulation in plants and animals. Support or Funding Information Supported by USDA-ARS Quality and Utilization of Agricultural Products Research Program 306 through CRIS 6054-41000-103-00D. DGAT2 mRNA as the major form in eukaryote cells This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.