The Relationship Research Between Diacylglycerol Acyltransferase 2 And TAG Synthesis And Scretion In Fatty Liver Of Goose

The liver is a main site of lipogenesis in poultry. The level of triglyceride (TAG)in plasma has a major relation with growth of adipose tissue and fatty deposition in poultry. TAG synthesized in liver can not be transported by blood, and it can not be utilized in peripheral tissue until it is assembled to lipoprotein in liver and secreted to blood in the form of very low density lipoprotein- triglyceride(VLDL-TAG). When the capability of productin of TAG in liver exceeds the capability of secreting TAG to blood in the form of (VLDL-TAG), a great of TAG would deposit in the liver, which could result in hepatic steatosis. The valued fatty liver is producted through the liver steatosis induced by overfeeding with a carbohydrate-rich corn-based diet in geese or ducks. The reason of fatty liver induced by overfeeding may be the destruction of TAG dynamic balance in liver.However,the concrete mechanism is unclear. As a diacylgycerol acyltransferase, making DAG react with fatty acyl-coA to synthsis TAG is the function mechanism of DGAT2. The level of DGAT2 expression is most high in the tissues of vigorous fat metabolism (such as liver, white adipose tissue), which means DGAT2 plays an important role in lipid metabolism. DGAT2 not only plays an important role in TAG synthesis, but it is essential for the life of animals. The mouse knocked DGAT2 gene soon died after birth.So,in the study, Landes goose (whose performance of liver product is good) and Sichuan white goose (whose performance of liver product is poor) are used as experiment objects, and we researched the overfeeding effect to body composition (such as TAG content of hepatic lipids) ,plamsa parameter (such as VLDL and TAG concentration in plasma), the lipid deposit diversity of the two species of goose, the effect of overfeeding to DGAT2 expression and activity and the influence of DGAT2 gene to TAG synthesis and secretion in liver. The main results are listed as follows:1. Overfeeding could enhance the growth of the liver and extrahepatic adipose tissue, but its main contribution is promoting TAG deposition in liver and then result in hepatic steatosis to form fatty liver.Overfeeding could infulence VLDL, TAG, Glu, Insulin concentration in plasma,but the degree may exist diversity species...