title: Cloning and characterization of microsomal triglyceride transfer protein gene and its potential connection with peroxisome proliferator-activated receptor (PPAR) in blunt snout bream (Megalobrama amblycephala).
abstract: Microsomal triglyceride transfer protein (MTTP), a major intracellular protein capable of transferring neutral lipids, plays a pivotal role in the assembly and secretion of apolipoprotein B-containing lipoproteins. In this study, MTTP cDNA was firstly cloned from the liver of blunt snout bream (Megalobrama amblycephala), the full-length cDNA covered 3457-bp with an open reading frame of 2661-bp, which encodes 886 amino acids, including a putative signal peptide of 24 amino acids long. After the feeding trial, a graded tissue-specific expression pattern of MTTP was observed and high expression abundance in the liver and intestine indicated its major function in lipid transport in this fish species. In addition, expression of genes encoding MTTP as well as peroxisome proliferator-activated receptor (PPAR), which are transcription factors and serve as key regulators in lipid homoeostasis, was all affected by dietary lipid and choline supplementations. Elevated dietary lipid levels significantly increased the liver, intestinal and muscle MTTP mRNA abundance. Additionally, the down-regulation of MTTP expression in the liver and muscle was observed when fish were fed with inadequate choline supplementation in high-fat diet, yet up-regulated as supplementing extra choline in diet. Expressions of PPARα and PPARβ in the liver and muscle showed similar trend of MTTP expression. The results suggested the potential connection of MTTP and PPAR in response to different dietary nutritional factors. Furthermore, extra choline supplementations could promote lipid transfer and enhance fatty acid oxidation, which indicated a molecular mechanism of choline on diminishing fat accumulation in blunt snout bream.
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China.
authors.forename: Jun-Yi
authors.initials: JY
authors.lastname: Li
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China.
authors.forename: Ding-Dong
authors.initials: DD
authors.lastname: Zhang
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China.
authors.forename: Guang-Zhen
authors.initials: GZ
authors.lastname: Jiang
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China.
authors.forename: Xiang-Fei
authors.initials: XF
authors.lastname: Li
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China.
authors.forename: Chun-Nuan
authors.initials: CN
authors.lastname: Zhang
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China.
authors.forename: Man
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China. Electronic address: wbliu@njau.edu.cn.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Liu
authors.affiliation: Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, China. Electronic address: xuweina@njau.edu.cn.
authors.forename: Wei-Na
authors.initials: WN
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D003001:Cloning, Molecular; D059305:Diet, High-Fat; D019587:Dietary Supplements; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D047492:Peroxisome Proliferator-Activated Receptors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D021541:Sea Bream / Q000235:genetics* / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D029941:Fish Proteins; D047492:Peroxisome Proliferator-Activated Receptors; D012333:RNA, Messenger; C106092:microsomal triglyceride transfer protein; D002794:Choline
keywords: Blunt snout bream; Choline supplementations; High-fat diet; Microsomal triglyceride transfer protein; Peroxisome proliferator-activated receptor