Steroid inhibition of protein incorporation by isolated amphibian oocytes
- Johns Hopkins Univ., Baltimore, MD (United States). School of Hygiene and Public Health; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology Division
The relationship between blood protein (vitellogenin) incorporation and nuclear maturation was studied in individual amphibian oocytes after in vitro exposure to desoxycorticosterone acetate (DOCA). Isolated Rana pipiens oocytes were incubated in vitro with radioactively labeled oocyte yolk precursor ([3H]vitellogenin) obtained from estrogenized Xenopus laevis. Incorporation of labeled vitellogenin into the oocytes continued over a 24-h period. Oocytes simultaneously exposed to DOCA and to labeled vitellogenin exhibited both inhibition of vitellogenin incorporation and stimulation of nuclear maturation and cortical changes. Inhibition of vitellogenin incorporation was observed after approximately 9 h of incubation and was correlated with the time of nuclear breakdown. Preincubation of oocytes in steroid for 9 h essentially terminated vitellogenin incorporation. Incorporation of vitellogenin occurred after removal of follicle cells from the oocyte by a short treatment with EDTA. These results demonstrate the macromolecular vitellogenin transport system remains operative in oocytes which can undergo nuclear maturation and that the steroid DOCA can affect its function. Evidence suggests that the mechanism of steroid inhibition is in part the result of inhibition of the micropinocytotic process in the oocyte cortex.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER). Biological Systems Science Division
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1629486
- Journal Information:
- Journal of Cell Biology, Vol. 61, Issue 1; ISSN 0021-9525
- Publisher:
- Rockefeller University PressCopyright Statement
- Country of Publication:
- United States
- Language:
- English
The Use of Xenopus Oocytes for the Study of Ion Channel
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journal | January 1987 |
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