Recently, the team of researcher Xie Jun from the Pearl River Fisheries Research Institute of the Chinese Academy of Fishery Sciences has made new progress in the study of grass carp fat accumulation regulation. The research paper”Farnesoid X receptor is an effective target for modulating lipid accumulation in grass carp, Ctenopharyngodon idella” Published online in Aquaculture, an international professional journal for aquatic products (2020, impact factor IF=3.224), the paper was funded by the National Natural Science Foundation of China, the Natural Science Foundation of Guangdong Province, and the National Bulk Freshwater Fish Industry Technology System Project. Dr. Tian Jingjing and Master Jin Yaqi from the Pearl River Research Institute are the co-first authors of the paper. Researcher Xie Jun and associate researcher Yu Ermeng from the Pearl River Research Institute are the co-corresponding authors of the paper.
Improving the quality and efficiency of aquaculture is an important direction of the current industry. The excessive accumulation of fat in cultured grass carp is one of the bottlenecks in the process of quality improvement. The excessive accumulation of mesenteric fat in grass carp and Fatty liver has seriously affected the quality of the product. In order to find the key molecular switch that regulates the accumulation of fat in fish, the team used fish farnesoid receptor (FXR) as a candidate molecular target to carry out a series of studies on the regulation pathway. The main conclusions are as follows:
1. It is confirmed that the FXR gene plays a negative regulatory role in the fat accumulation process of grass carp. Through the use of receptor inhibitors and activators, it was found that activating FXR activity significantly reduced the content of triglycerides and cholesterol in the liver of grass carp, while inhibiting FXR activity increased the fat accumulation of liver and abdominal fat.
2. It was found that intestinal antibiotics regulate grass carp FXR through the tract flora. Using dual antibodies to interfere with the composition of the intestinal flora, it was found that the FXR signaling pathway was weakened and led to an increase in liver fat accumulation.
3. To clarify the non-classical mechanism of FXR regulating fat accumulation in grass carp. After activating the activity of FXR in the intestinal cells of grass carp, it does not need to go through the blood pathway to directly cause the synthesis of fatty acids and cholesterol in liver cells to weaken, and the ability to form lipid droplets is reduced, thereby alleviating the accumulation of liver fat in grass carp.
The results of this study provide a new theoretical basis for the regulation of grass carp fat accumulation, and also confirm the new harm of antibiotic abuse. In the future, our team will focus on this molecular pathway to screen related The quality control substances provide a feasible technical way for the high-quality development of the breeding industry.