Expression profiles of three types of GnRH during sex-change in the protandrous cinnamon clownfish, Amphiprion melanopus: Effects of exogenous GnRHs.
Gonadotropin-releasing hormones (GnRHs) play pivotal roles in the control of reproduction and gonadal maturation in teleost fish. Fish have multiple GnRH genes that encode structurally distinct peptides. We identified salmon GnRH (sGnRH), seabream GnRH (sbGnRH), and chicken GnRH-II (cGnRH-II) by cDNA cloning in cinnamon clownfish (Amphiprion melanopus) using reverse transcription-PCR (RT-PCR) and rapid amplification of cDNA ends-PCR (RACE-PCR). Gene identity was confirmed by sequence alignment and subsequent phylogenetic analyses. We also investigated GnRH mRNA expression in the gonads by quantitative real time-PCR (Q-PCR), and measured plasma estradiol-17β (E(2)) levels in immature fish following treatment with the three molecular forms of GnRHs. The expression levels of sGnRH, sbGnRH, and cGnRH-II mRNA were higher in mature testes and ovaries, as compared to the levels in gonads at earlier stages of maturity. The levels of the three prepro-GnRH mRNA species and the plasma E(2) levels increased after injection of the three GnRH variants. These findings support the hypothesis that GnRH peptides play important roles in the regulation of the hypothalamic-pituitary-gonadal axis and are probably involved in paracrine control of gonadal development and sex change in cinnamon clownfish.
Division of Marine Environment & Bioscience, Korea Maritime University, Busan 606-791, Republic of Korea.
Na Na
NN
Kim
Hyun Suk
HS
Shin
Hamid R
HR
Habibi
Jehee
J
Lee
Cheol Young
CY
Choi
D000595:Amino Acid Sequence; D000818:Animals; D004958:Estradiol / Q000097:blood; D005260:Female; D020869:Gene Expression Profiling; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D006066:Gonads / Q000254:growth & development / Q000378:metabolism; D057850:Hermaphroditic Organisms / Q000235:genetics / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010473:Perciformes / Q000235:genetics / Q000502:physiology*; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012727:Sex Characteristics; D019849:Sex Determination Processes / Q000235:genetics*; D046509:Tissue Culture Techniques
D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol