The functions and mechanisms of sequence differences of DGAT1 gene on milk fat synthesis between dairy cow and buffalo

Abstract

In this research communication we describe the DGAT1 sequence and promoter region in dairy cows and buffalo and compare the activities of DGAT1 between the two species in order to increase knowledge of the cause of milk fat variation. pGL-3 basic vectors were used to construct the reporter gene. Based on the predicted promoter region, 4 truncated plasmid vectors were constructed in cow-DGAT1 and 3 plasmid vectors in buffalo-DGAT1. Each reporter plasmid was transfected into the bovine mammary epithelial cell (BMEC), 293T cell, and CHO cells to analyze the activity using Dual-Luciferase Reporter Assay System. The results show that the region between −93 to −556 bp was essential for cow promoter activity while −84 to −590 bp was essential for buffalo promoter activity revealing these regions contain core promoter. The buffalo has higher promoter activity than cow yet it was not statistically significant. Comparison of candidate mutation K232A between cow and buffalo population revealed the presence of both the allelic population in dairy cows (lysine and alanine) however, only K (lysine) allelic amino acid was found in buffalo population. The absence of the alanine allelic population from buffalo explains the higher fat content of buffalo milk.

CIDEA Regulates De Novo Fatty Acid Synthesis in Bovine Mammary Epithelial Cells by Targeting the AMPK/PPARγ Axis and Regulating SREBP1

“…36,37 The AGPAT6 gene is considerably upregulated during lactation as a result of the addition of fatty acids to the SN-2 site of acylglycero-3-phosphate, 32 whereas DGAT1 catalyzes the final step of the TAG synthesis process. 38 Our results show a decrease in the mRNA level of DGAT1 in the bMECs treated with shRNA-CIDEA, which suggests that CIDEA affects the expression of DGAT1.…”

“…The enzymes acylglycero-3-phosphate O -acyltransferase (AGPAT6) and diacylglyceryl transferase 1 (DGAT1) play vital roles in the synthesis of TAG in the mammary glands of dairy cows. , The AGPAT6 gene is considerably upregulated during lactation as a result of the addition of fatty acids to the SN-2 site of acylglycero-3-phosphate, whereas DGAT1 catalyzes the final step of the TAG synthesis process . Our results show a decrease in the mRNA level of DGAT1 in the bMECs treated with shRNA-CIDEA, which suggests that CIDEA affects the expression of DGAT1.…”

Genome-Wide Association Study of Lactation Traits in Chinese Holstein Cows in Southern China

“…Numerous studies have reported the association between the DGAT1 gene and milk fat synthesis [29,30]. Furthermore, the DGAT1 gene is a major gene in inflammatory response and lipid metabolism, encoding an enzyme that catalyzes the last step of triacylglycerol synthesis [31], and significantly affecting energy metabolism during lactation in dairy cows [32]. The CYC1 gene encodes a subunit of the cytochrome bc1 complex, which is associated with redox processes, and it has been reported that the CYC1 gene is an important candidate for albumin synthesis [23].…”

Comparative metabolomics analysis of milk components between Italian Mediterranean buffaloes and Chinese Holstein cows based on LC-MS/MS technology

“…Despite of these positive aspects, buffaloes produce lower milk yield. The understanding of the biological mechanisms behind these differences between the buffaloes and bovines gives rise to the interest of many researchers [ 31 , 32 ]. Previously, potential protein markers and intestinal microbiome have been positively associated with differences in milk components between buffaloes and cows [ 33 ].…”