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Transient increase in calcium efflux accompanies fertilization in Chlamydomonas
Mating in Chlamydomonas is a complex process initiated by contact of gametic flagellar surfaces, resulting in transmission of a signal from the flagella to the cell bodies. This signal triggers later events of cell wall loss, mating structure activation, and cell-cell fusion. Little is known about t...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1983
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2112523/ https://www.ncbi.nlm.nih.gov/pubmed/6885905 |
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collection | PubMed |
description | Mating in Chlamydomonas is a complex process initiated by contact of gametic flagellar surfaces, resulting in transmission of a signal from the flagella to the cell bodies. This signal triggers later events of cell wall loss, mating structure activation, and cell-cell fusion. Little is known about the nature of the signal or the role of Ca in these events. It was found that extracellular Ca is not necessary for successful mating in Chlamydomonas. However, cells will take up Ca from the medium in a linear manner for many hours and will accumulate micromolar concentrations, presumably by sequestering Ca within intracellular storage sites. If gametic cells of one mating type (preloaded with 45Ca) are mated with gametes of the opposite mating type (preloaded with unlabeled calcium), there is a rapid, transient increase in calcium efflux rate (20 times that of the control) that lasts approximately 6 min. This effect is not associated with cell-cell fusion, since the same observation is made if (+) gametes preloaded with 45-Ca are agglutinated by isolated flagella from (-) gametes preloaded with unlabeled Ca. Other experiments have shown that the increased efflux rate is not a simple consequence of cell wall release. Ca efflux in unmated gametes is greatly reduced in deflagellated cells, suggesting that much of the Ca movement is associated with the flagellar membrane. Although signaling itself may involve Ca fluxes across the flagellar membrane, it is also possible that a consequence of signaling is release of Ca from intracellular storage sites (perhaps functional equivalents of the sarcoplasmic reticulum). The observed transient increase in Ca efflux rate may reflect a transient increase in the cytoplasmic free-Ca concentration. This increase in cytoplasmic Ca may regulate the later events in mating (such as cell wall release and mating structure activation). |
format | Text |
id | pubmed-2112523 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1983 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21125232008-05-01 Transient increase in calcium efflux accompanies fertilization in Chlamydomonas J Cell Biol Articles Mating in Chlamydomonas is a complex process initiated by contact of gametic flagellar surfaces, resulting in transmission of a signal from the flagella to the cell bodies. This signal triggers later events of cell wall loss, mating structure activation, and cell-cell fusion. Little is known about the nature of the signal or the role of Ca in these events. It was found that extracellular Ca is not necessary for successful mating in Chlamydomonas. However, cells will take up Ca from the medium in a linear manner for many hours and will accumulate micromolar concentrations, presumably by sequestering Ca within intracellular storage sites. If gametic cells of one mating type (preloaded with 45Ca) are mated with gametes of the opposite mating type (preloaded with unlabeled calcium), there is a rapid, transient increase in calcium efflux rate (20 times that of the control) that lasts approximately 6 min. This effect is not associated with cell-cell fusion, since the same observation is made if (+) gametes preloaded with 45-Ca are agglutinated by isolated flagella from (-) gametes preloaded with unlabeled Ca. Other experiments have shown that the increased efflux rate is not a simple consequence of cell wall release. Ca efflux in unmated gametes is greatly reduced in deflagellated cells, suggesting that much of the Ca movement is associated with the flagellar membrane. Although signaling itself may involve Ca fluxes across the flagellar membrane, it is also possible that a consequence of signaling is release of Ca from intracellular storage sites (perhaps functional equivalents of the sarcoplasmic reticulum). The observed transient increase in Ca efflux rate may reflect a transient increase in the cytoplasmic free-Ca concentration. This increase in cytoplasmic Ca may regulate the later events in mating (such as cell wall release and mating structure activation). The Rockefeller University Press 1983-08-01 /pmc/articles/PMC2112523/ /pubmed/6885905 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Articles Transient increase in calcium efflux accompanies fertilization in Chlamydomonas |
title | Transient increase in calcium efflux accompanies fertilization in Chlamydomonas |
title_full | Transient increase in calcium efflux accompanies fertilization in Chlamydomonas |
title_fullStr | Transient increase in calcium efflux accompanies fertilization in Chlamydomonas |
title_full_unstemmed | Transient increase in calcium efflux accompanies fertilization in Chlamydomonas |
title_short | Transient increase in calcium efflux accompanies fertilization in Chlamydomonas |
title_sort | transient increase in calcium efflux accompanies fertilization in chlamydomonas |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2112523/ https://www.ncbi.nlm.nih.gov/pubmed/6885905 |