title: Characterization of GHRs, IGFs and MSTNs, and analysis of their expression relationships in blunt snout bream, Megalobrama amblycephala.
abstract: In order to test the hypothesis that the expression levels of GH/IGF axis genes would be negatively related to the expression of the myostatin genes in fish species, we cloned six growth regulating genes including growth hormone receptors-1/-2 (GHRs), insulin-like growth factors-I/-II (IGFs) and myostatins-a/-b (MSTNs) from blunt snout bream (Megalobrama amblycephala). The contents of mRNA transcripts for the six genes were determined in the different tissues of adult and developmental stages for the embryonic and larval periods. The results of quantitative real-time PCR showed that GHRs, IGFs and MSTNs were widely expressed in the tissues we tested, with the relatively lower expression levels in mesonephros, gonad and spleen for the six genes. The analysis of expression correlation coefficients among these six genes showed that GHR 1, GHR 2 and MSTN b were correlated with each other in adult tissues (P<0.01). For the developmental stages, GHR 1 had a similar expression pattern to GHR 2 during the examined periods, both with the highest expression levels at 160 hpf (hours post-fertilization) (P<0.05). IGF-II had higher expression levels than that of IGF-I before 400 hpf (P<0.05), while IGF-I was active after 52 hpf. The maximum of MSTN a and MSTN b mRNA levels were at 24 hpf and 400 hpf, respectively. The analysis of expression correlation coefficients showed that GHR 1, GHR 2, IGF-I, IGF-II and MSTN b were positively correlated with each other during embryonic development (P<0.01). The results from this study suggested that the relationship between GH/IGF axis genes and MSTNs was complex and not absolutely negative correlated in fish species.
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, Hubei 430070, China; School of Biological Science, Victoria University of Wellington, Wellington 6140, New Zealand.
authors.forename: Cong
authors.initials: C
authors.lastname: Zeng
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, Hubei 430070, China; Tianjin Fisheries Research Institute, Tianjin 300221, China.
authors.forename: Xiao-Lian
authors.initials: XL
authors.lastname: Liu
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, Hubei 430070, China.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.
authors.forename: Jin-Gou
authors.initials: JG
authors.lastname: Tong
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, Hubei 430070, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, Hubei 430070, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, Hubei 430070, China. Electronic address: gaozexia@hotmail.com.
authors.forename: Ze-Xia
authors.initials: ZX
authors.lastname: Gao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003530:Cyprinidae / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D008297:Male; D008969:Molecular Sequence Data; D055435:Myostatin / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D011986:Receptors, Somatotropin / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013002:Somatomedins / Q000235:genetics* / Q000378:metabolism
chemical_list: D055435:Myostatin; D012333:RNA, Messenger; D011986:Receptors, Somatotropin; D013002:Somatomedins
keywords: Cloning; DO; Expression relationships; GH; GH/IGF axis; GHR; GHRs; GLM; IGF; IGFBP; IGFs; MSTN; MSTNs; Megalobrama amblycephala; RACE; SE; TGF; UTR; days post-hatching; dissolved oxygen; dph; general linear model; growth hormone; growth hormone receptor; growth hormone/insulin-like growth factors (GH/IGF) axis; hours post-fertilization; hours post-hatching; hpf; hph; insulin-like growth factor; insulin-like growth factor binding protein (IGFBP); myostatin; qRT-PCR; quantitative reverse transcription polymerase chain reaction; rapid amplification of cDNA ends; standard error; transforming growth factor; untranslated region