| Autogamy in Paramecium. Cell cycle stage-specific commitment to meiosis. | |
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MedLine Citation:
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PMID: 3743667 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Autogamy is a process of meiosis and fertilization which takes place in unpaired Paramecium cells, and which is triggered by starvation. This study examines the consequences of nutritional down-shift at various points within the cell cycle on the occurrence of autogamy. It shows that cells become committed to autogamy in a two-step process. An initial point of commitment to autogamy occurs about 100 min prior to the median time of cell division (cell cycle duration, 330 min). Cells which have become committed to autogamy initiate meiosis following the next fission, others complete another vegetative cell cycle before undergoing meiosis. Treatments that perturb the cell cycle and displace the point of commitment of division also displace the point of initial commitment to autogamy to the same extent. The initial commitment to autogamy can be reversed by refeeding. The second, final, point of commitment to autogamy occurs about 30 min after the fission, immediately prior to initiation of meiosis, and coincides with the beginning of meiosis. If cells are refed at this point, or at later stages, autogamy continues. Autogamy is not well synchronized either in naturally starved cultures or in those subjected to abrupt nutritional down-shift. This is a consequence of the cell cycle stage dependence of entry into autogamy. Autogamy occurs synchronously in samples of dividers selected from asynchronous cultures 2 or more hours after nutritional down-shift. The timing of the events of conjugation and autogamy coincide when the pre-autogamous fission is aligned temporally with the initial contact of mating cells. |
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Authors:
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J D Berger |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Experimental cell research Volume: 166 ISSN: 0014-4827 ISO Abbreviation: Exp. Cell Res. Publication Date: 1986 Oct |
Date Detail:
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Created Date: 1986-10-22 Completed Date: 1986-10-22 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0373226 Medline TA: Exp Cell Res Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 475-85 Citation Subset: IM |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Cell Cycle Cell Division Paramecium / cytology*, physiology |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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