title: Cloning and pattern of gsdf mRNA during gonadal development in the protogynous Epinephelus akaara.
abstract: Gonadal soma-derived factor (gsdf) is a teleost- and gonad-specific growth factor involved in early germ cell development. The red spotted grouper, Epinephelus akaara, as a protogynous hermaphrodite, provides a novel model for understanding the mechanisms of sex determination and differentiation in teleosts. In the present study, a 2307-bp long gsdf gene was cloned from E. akaara and there was further analysis of its tissue distribution and gonadal patterns of gene expression during the female phase and sex change developmental stages. The cellular localization of gsdf at the late transitional developmental stage was also analyzed. In addition, the concentrations of serum sex steroid hormones (E2, 11-KT and DHP) were determined. The gsdf transcripts were exclusively localized in the gonad. During the female phase at an early developmental stage, when the ovotestis contained mainly oogonia and primary growth oocytes, the gsdf mRNA was relatively more abundant. The relative abundance of gsdf decreased, however, and the lesser amount was sustained with the advancement of oocyte development. During the transitional phase, the relative abundance of gsdf mRNA increased slightly at the early developmental stage and there were further increases in relative abundance in the late developmental stage, and the gsdf transcripts were observed in the Sertoli cells surrounding early developing spermatogonia. Among the sex steroids, 11-KT concentrations were positively correlated with amount of gsdf mRNA during sex change. These results suggest that gsdf could have roles in regulating pre-meiotic germ cell proliferation and be involved in sex change in E. akaara.
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen 361102, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361102, China.
authors.forename: Wan Shu
authors.initials: WS
authors.lastname: Hong
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; Fujian Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen 361102, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361102, China. Electronic address: chenshixi@xmu.edu.cn.
authors.forename: Shi Xi
authors.initials: SX
authors.lastname: Chen
mesh_terms: D000523:Algestone / Q000097:blood; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004958:Estradiol / Q000097:blood; D005260:Female; D005399:Fishes / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006066:Gonads / Q000254:growth & development* / Q000378:metabolism; D057850:Hermaphroditic Organisms / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D000523:Algestone; D013739:Testosterone; D004958:Estradiol; C003600:11-ketotestosterone
keywords: Epinephelus akaara; Gsdf; Protogynous; Sex change