title: EST analysis on adipose tissue of rainbow trout Oncorhynchus mykiss and tissue distribution of adiponectin.
abstract: Although energy metabolism in mammals is critically regulated by adipokines from adipocytes, it is unclear whether this is the case in fish as well. In this study, over 30,000 expressed sequence tags (ESTs) were obtained from adipose tissue in rainbow trout Oncorhynchus mykiss peritoneal cavity and searched for genes possibly related to lipid metabolism. Large numbers of ESTs encoded digestive enzymes and hormones usually found in the pancreas in higher vertebrates, consistent with the fact that pancreatic cells are dispersed in the adipose tissue. Many ESTs encoded apolipoprotein C-I, fatty acid-binding proteins and lymphocyte G0/G1 switch protein 2, which function in lipid transport, fatty acid accumulation and adipocyte differentiation, respectively. None of the ESTs encoded adipokines. We therefore obtained a cDNA encoding adiponectin, an adipokine that regulates oxidation of glucose and lipids in peripheral tissues, using rainbow trout ESTs in the public database. Real-time RT-PCR analyses revealed that its transcript levels were high in muscle and quite low in adipose tissue. These results strongly suggest that adipocytes of rainbow trout and possibly other fish species, unlike those of mammals, are not involved in the production of adipokines.
authors.affiliation: Laboratory of Genome Science, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo, Japan. h-kondo@kaiyodai.ac.jp
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Kondo
authors.forename: Ryota
authors.initials: R
authors.lastname: Suga
authors.forename: Satomitsu
authors.initials: S
authors.lastname: Suda
authors.forename: Reiko
authors.initials: R
authors.lastname: Nozaki
authors.forename: Ikuo
authors.initials: I
authors.lastname: Hirono
authors.forename: Reiko
authors.initials: R
authors.lastname: Nagasaka
authors.forename: Gen
authors.initials: G
authors.lastname: Kaneko
authors.forename: Hideki
authors.initials: H
authors.lastname: Ushio
authors.forename: Shugo
authors.initials: S
authors.lastname: Watabe
mesh_terms: D052242:Adiponectin / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D020224:Expressed Sequence Tags; D050356:Lipid Metabolism / Q000235:genetics; D017686:Oncorhynchus mykiss / Q000235:genetics*; D014018:Tissue Distribution
chemical_list: D052242:Adiponectin