title: Correlation with larval body size of mRNA levels of growth hormone, growth hormone receptor I and insulin-like growth factor I in larval torafugu Takifugu rubripes.
abstract: The full-length of insulin-like growth factor (IGF) complementary (c)DNAs encoded by igf-I and igf-II from torafugu pufferfish Takifugu rubripes were cloned in the present study. The deduced amino acid sequences of the two genes showed c. 80% identity each with those of Igf-I and Igf-II from other teleosts, respectively. Two growth hormone (GH) receptors, ghr1 and ghr2, were also cloned in silico using the T. rubripes Fugu genome database. The transcripts of T. rubripes igf-I were detected in slow muscle, heart, skin, gill, liver and intestine but not in fast muscle, spleen and testis of adult fish, whereas those of igf-II were found in all tissues examined. Subsequently, the accumulated messenger (m)RNA levels of igf-I and igf-II were investigated in an F(2)  population derived from a male of an apparent fast-growing T. rubripes strain and a wild female T. rubripes together with those of other growth-related genes encoding Gh, Ghr1 and Ghr2, and with those of prolactin (Prl) and leptin (Lep) previously reported. The accumulated mRNA levels of igf-I, gh and ghr1 were significantly correlated to growth rate at larval stages in the population, but not for those of igf-II, prl, ghr2 and lep. Although it is unclear whether or not this phenotype is directly related to the heredity of the fast-growing strain, the findings suggest that the expression of igf-I, gh and ghr1 is involved in the regulation of growth rate at larval stages in T. rubripes.
authors.affiliation: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Kaneko
authors.forename: S
authors.initials: S
authors.lastname: Furukawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kurosu
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Takeshima
authors.forename: M
authors.initials: M
authors.lastname: Nishida
authors.forename: T
authors.initials: T
authors.lastname: Mitsuboshi
authors.forename: T
authors.initials: T
authors.lastname: Otaka
authors.forename: K
authors.initials: K
authors.lastname: Shirasu
authors.forename: T
authors.initials: T
authors.lastname: Koda
authors.forename: Y
authors.initials: Y
authors.lastname: Takemasa
authors.forename: S
authors.initials: S
authors.lastname: Aki
authors.forename: T
authors.initials: T
authors.lastname: Mochizuki
authors.forename: H
authors.initials: H
authors.lastname: Fukushima
authors.forename: Y
authors.initials: Y
authors.lastname: Fukuda
authors.forename: S
authors.initials: S
authors.lastname: Kinoshita
authors.forename: S
authors.initials: S
authors.lastname: Asakawa
authors.forename: S
authors.initials: S
authors.lastname: Watabe
mesh_terms: D000818:Animals; D049628:Body Size; D005786:Gene Expression Regulation; D013006:Growth Hormone / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D011986:Receptors, Somatotropin / Q000235:genetics*; D023741:Takifugu / Q000033:anatomy & histology / Q000254:growth & development
chemical_list: D012333:RNA, Messenger; D011986:Receptors, Somatotropin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone