Previtellogenic oocyte growth and transcriptional changes of steroidogenic enzyme genes in immature female Atlantic cod (Gadus morhua L.) after exposure to the androgens 11-ketotestosterone and testosterone.
We have studied in vivo, the effects of physiological androgen (11-ketotestosterone: 11-KT and testosterone: T) concentrations on the growth of cod previtellogenic oocytes and steroidogenic gene expression patterns. Immature female Atlantic cod were injected three times (days 0, 7 and 14) with 0.05, 0.5 and 5 mg/kg of 11-KT and T. The control group was injected with the carrier solvent (ethanol diluted 1:10 in sunflower oil). Quantitative histological analyses demonstrated growth and development of previtellogenic oocytes after exposure to androgens. The oocyte developmental effect of androgens was more pronounced in fish receiving 11-KT. Quantitative PCR analysis demonstrated dose- and androgen-specific modulation of mRNA expression for genes involved in steroidogenesis (StAR (steroidogenic acute regulatory) protein, P450scc (P450-mediated cholesterol side-chain cleavage), 20beta-HSD (20beta-hydroxysteroid dehydrogenase)) and cell growth control, namely--opioid growth factor receptor (OGF-R), progesterone receptor protein p23 (PR23P) and apoptosis-inducing TAF9-like domain 1 (TAF9). Messenger RNA species associated with the zona pelucida, namely--the zona pellucida protein A domain (ZPA) and egg envelope glycoprotein (EeG) were modulated based on dose and androgen type. Cyclin-B mRNA expression was not affected by androgen exposure. Interestingly, we showed recently that these transcripts were responsive to in vitro androgen exposure in previtellogenic cod ovary. In conclusion, the present study adds further information regarding the effects of androgens on the development of previtellogenic oocytes, suggesting androgen control of early oocyte growth in cod. The enhanced effects of 11-KT on oocyte growth support our hypothesis that non-aromatizable androgens play significant roles in the regulation of early previtellogenic oocyte growth and development.
Kortner
Trond M
TM
Department of Biology, Norwegian University of Science and Technology (NTNU), Høgskoleringen 5, 7491 Trondheim, Norway.
Rocha
Eduardo
E
Arukwe
Augustine
A
D000728:Androgens / Q000737:chemistry; D000818:Animals; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics*; D003349:Cortisone Reductase / Q000235:genetics*; D019926:Cyclin B / Q000187:drug effects / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004527:Egg Proteins / Q000187:drug effects / Q000235:genetics; D005260:Female; D048389:Gadus morhua / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000235:genetics; D009865:Oocytes / Q000187:drug effects* / Q000254:growth & development; D010750:Phosphoproteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000235:genetics; D011957:Receptors, Opioid / Q000187:drug effects / Q000235:genetics; D011980:Receptors, Progesterone / Q000187:drug effects / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D035381:TATA-Binding Protein Associated Factors / Q000187:drug effects / Q000235:genetics; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology*; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects* / Q000235:genetics; D000072216:Zona Pellucida Glycoproteins; D000098682:Steroidogenic Acute Regulatory Protein
D000728:Androgens; D019926:Cyclin B; D004527:Egg Proteins; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011957:Receptors, Opioid; D011980:Receptors, Progesterone; D035381:TATA-Binding Protein Associated Factors; D000072216:Zona Pellucida Glycoproteins; D000098682:Steroidogenic Acute Regulatory Protein; D013739:Testosterone; D003349:Cortisone Reductase; D002786:Cholesterol Side-Chain Cleavage Enzyme