The effects of 11-ketotestosterone on ovarian physiology of previtellogenic captive hapuku (Polyprion oxygeneios).
The present study investigated, for the first time in a perciform teleost, the effects of in vivo 11-ketotestosterone (11-KT) treatment using slow-release implants on ovarian development and gonadotropin receptor mRNA levels in captive previtellogenic females of hapuku (Polyprion oxygeneios). At the cellular/functional level, ovarian development and ovarian and hepatic total lipid levels were examined. At the molecular level, transcript abundance of ovarian follicle-stimulating hormone receptor (FSH-R) and luteinizing hormone receptor (LH-R) was measured. Additionally, cyclic adenosine monophosphate (cAMP) levels in ovarian fragments from placebo and 11-KT implanted fish incubated with or without human chorionic gonadotropin (hCG) in vitro were compared between groups. There were no significant differences between treatments with regard to oocyte size and lipid contents of liver and ovary. Messenger RNA levels of FSH-R and LH-R were significantly lower in the treated females. Similarly, cAMP levels were significantly lower in the ovarian fragments of the 11-KT implanted females. These results suggest that 11-KT specifically, but possibly androgens in general, may not have an important function in regulating gonadal development of previtellogenic female hapuku; indeed, if anything, 11-KT appeared to have a detrimental effect and its use will not be beneficial in advancing sexual maturity of hapuku in aquaculture.
University of Otago, Department of Zoology, 340 Great King St., Dunedin 9016, New Zealand; NIWA, Bream Bay Aquaculture Park, PO Box 147, Ruakaka 0151, New Zealand. Electronic address: kohya760@student.otago.ac.nz.
Yair Y
YY
Kohn
Jane E
JE
Symonds
P Mark
PM
Lokman
D000818:Animals; D048429:Cell Size; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005398:Fisheries; D015870:Gene Expression; D006801:Humans; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D009865:Oocytes / Q000502:physiology; D010053:Ovary / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010473:Perciformes / Q000254:growth & development*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011962:Receptors, FSH / Q000235:genetics / Q000378:metabolism; D011974:Receptors, LH / Q000235:genetics / Q000378:metabolism; D012102:Reproductive Control Agents / Q000494:pharmacology; D013739:Testosterone / Q000031:analogs & derivatives* / Q000502:physiology
D006063:Chorionic Gonadotropin; D029941:Fish Proteins; D012333:RNA, Messenger; D011962:Receptors, FSH; D011974:Receptors, LH; D012102:Reproductive Control Agents; D013739:Testosterone; D000242:Cyclic AMP; C003600:11-ketotestosterone
11-ketotestostereone; Aquaculture; Fish endocrinology; Gonadotropin receptors; Hormonal therapy; Polyprion oxygeneios; Sexual maturation