Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, 266071, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao, 266237, China.
Fish Physiol Biochem. 2020 Aug;46(4):1603-1619. doi: 10.1007/s10695-020-00815-7. Epub 2020 May 15.
The tissue distribution pattern of lipid is highly diverse among different fish species. Tiger puffer has a special lipid storage pattern, storing lipid predominantly in liver. In order to better understand the lipid physiology in fish storing lipid in liver, the present study preliminarily investigated the tissue distribution of transcription for 29 lipid metabolism-related genes in tiger puffer, which are involved in lipogenesis, fatty acid oxidation, biosynthesis and hydrolysis of glycerides, lipid transport, and relevant transcription regulation. Samples of eight tissues, brain, eye, heart, spleen, liver, intestine, skin, and muscle, from fifteen juvenile tiger puffer were used in the qRT-PCR analysis. The intestine and brain had high transcription of lipogenic genes, whereas the liver and muscle had low expression levels. The intestine also had the highest transcription level of most apolipoproteins and lipid metabolism-related transcription factors. The transcription of fatty acid β-oxidation-related genes was low in the muscle. The peroxisomal fatty acid oxidation may dominate over mitochondrial β-oxidation in the liver and intestine of tiger puffer, and the MAG pathway probably predominates over the G3P pathway in re-acylation of absorbed lipids in the intestine. The intracellular glyceridases were highly transcribed in the brain, eye, and heart. In conclusion, in tiger puffer, the intestine could be a center of lipid metabolism whereas the liver is more likely a pure storage organ for lipid. The lipid metabolism in the muscle could also be inactive, possibly due to the very low level of intramuscular lipid.
不同鱼类的脂质组织分布模式差异很大。老虎斑具有特殊的脂质储存模式，主要在肝脏中储存脂质。为了更好地了解肝脏储存脂质的鱼类的脂质生理学，本研究初步研究了 29 种与脂质代谢相关的基因在老虎斑中的转录组织分布，这些基因涉及脂质合成、脂肪酸氧化、甘油酯的生物合成和水解、脂质转运以及相关的转录调节。从 15 条幼年老虎斑中采集了 8 种组织（脑、眼、心、脾、肝、肠、皮肤和肌肉）的样本，用于 qRT-PCR 分析。肠和脑具有高的生脂基因转录水平，而肝脏和肌肉的表达水平较低。肠还具有大多数载脂蛋白和脂质代谢相关转录因子的最高转录水平。肌肉中脂肪酸β-氧化相关基因的转录水平较低。过氧化物酶体脂肪酸氧化可能在老虎斑的肝脏和肠道中占主导地位，而 MAG 途径可能在肠道中吸收脂质的再酰化中占主导地位。细胞内甘油酶在脑、眼和心脏中高度转录。总之，在老虎斑中，肠可能是脂质代谢的中心，而肝脏更可能是脂质的纯储存器官。肌肉中的脂质代谢也可能不活跃，可能是由于肌肉内脂质水平非常低。
