PUBLICATION
Potential targets of transforming growth factor-beta1 during inhibition of oocyte maturation in zebrafish
- Authors
- Kohli, G., Clelland, E., and Peng, C.
- ID
- ZDB-PUB-051005-3
- Date
- 2005
- Source
- Reproductive Biology and Endocrinolgy 3: 53 (Journal)
- Registered Authors
- Peng, Chun
- Keywords
- none
- MeSH Terms
-
- Animals
- Chorionic Gonadotropin/pharmacology
- Cortisone Reductase/biosynthesis
- Cortodoxone/analogs & derivatives
- Cycloheximide/pharmacology
- Dactinomycin/pharmacology
- Down-Regulation
- Female
- Gene Expression/drug effects
- Hydroxyprogesterones/antagonists & inhibitors
- Oocytes/drug effects
- Oocytes/physiology*
- Ovarian Follicle/drug effects
- Ovarian Follicle/physiology
- Receptors, FSH/biosynthesis
- Receptors, LH/biosynthesis
- Receptors, LH/metabolism
- Receptors, Progesterone/biosynthesis
- Transforming Growth Factor beta/physiology*
- Transforming Growth Factor beta1
- Zebrafish
- Zebrafish Proteins/biosynthesis
- PubMed
- 16197550 Full text @ Reprod. Biol. Endocrinol.
Citation
Kohli, G., Clelland, E., and Peng, C. (2005) Potential targets of transforming growth factor-beta1 during inhibition of oocyte maturation in zebrafish. Reproductive Biology and Endocrinolgy. 3:53.
Abstract
BACKGROUND: TGF-beta is a multifunctional growth factor involved in regulating a variety of cellular activities. Unlike mammals, the function of TGF-beta in the reproduction of lower vertebrates, such as fish, is not clear. Recently, we showed that TGF-beta1 inhibits gonadotropin- and 17alpha, 20beta-dihydroxyprogesterone (DHP)-induced maturation in zebrafish. The aim of the present study was to investigate the mechanisms underlying this action. METHOD: To determine if the effect of TGF-beta1 on oocyte maturation involves transcription and/or translation, ovarian follicles were pre-treated with actinomycin D, a blocker of transcription, and cyclohexamide, an inhibitor of translation, and incubated with hCG or DHP, either alone or in combination with TGF-beta1 and oocyte maturation scored. To determine the effect of TGF-beta1 on mRNA levels of several key effectors of oocyte maturation, three sets of experiments were performed. First, follicles were treated with control medium or TGF-beta1 for 2, 6, 12, and 24h. Second, follicles were treated with different concentrations of TGF-beta1 (0 to 10ng/ml) for 18h. Third, follicles were incubated with hCG in the absence or presence of TGF- beta1 for 18h. At the end of each experiment, total RNA was extracted and reverse transcribed. PCR using primers specific for 20beta-hydroxysteroid dehydrogenase (20beta-HSD) which is involved in DHP production, follicle stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), the two forms of membrane progestin receptor: mPR-alpha and mPR-beta, as well as GAPDH (control), were performed. RESULTS: Treatment with actinomycin D, a blocker of transcription, reduced the inhibitory effect of TGF-beta1 on DHP-induced oocyte maturation, indicating that the inhibitory action of TGF-beta1 is in part due to regulation of gene transcription. Treatment with TGF-beta1 caused a dose and time-dependent decrease in mRNA levels of 20beta-HSD, LHR and mPR-beta in follicles. On the other hand, TGF-beta1 had no effect on mPR-alpha mRNA expression and increased FSHR mRNA levels. Furthermore, hCG upregulated 20beta-HSD, LHR and mPR-beta mRNA levels, but this stimulatory effect was blocked by TGF-beta1. CONCLUSION: These findings suggest that TGF-beta1 acts at multiple sites, including LHR, 20beta-HSD and mPR-beta, to inhibit zebrafish oocyte maturation.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping