Cleavage-furrow formation without F-actin in Chlamydomonas
| Autor: | Frederick R. Cross, Masayuki Onishi, John R. Pringle, James G. Umen |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0303 health sciences
animal structures Multidisciplinary biology Cell division urogenital system Chemistry Chlamydomonas Cleavage furrow formation Chlamydomonas reinhardtii macromolecular substances biology.organism_classification Cell biology 03 medical and health sciences 0302 clinical medicine embryonic structures Myosin Cleavage furrow 030217 neurology & neurosurgery Actin Cytokinesis 030304 developmental biology |
| Zdroj: | Proceedings of the National Academy of Sciences. 117:18511-18520 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1920337117 |
| Popis: | It is widely believed that cleavage-furrow formation during cytokinesis is driven by the contraction of a ring containing F-actin and type-II myosin. However, even in cells that have such rings, they are not always essential for furrow formation. Moreover, many taxonomically diverse eukaryotic cells divide by furrowing but have no type-II myosin, making it unlikely that an actomyosin ring drives furrowing. To explore this issue further, we have used one such organism, the green alga Chlamydomonas reinhardtii. We found that although F-actin is associated with the furrow region, none of the three myosins (of types VIII and XI) is localized there. Moreover, when F-actin was eliminated through a combination of a mutation and a drug, furrows still formed and the cells divided, although somewhat less efficiently than normal. Unexpectedly, division of the large Chlamydomonas chloroplast was delayed in the cells lacking F-actin; as this organelle lies directly in the path of the cleavage furrow, this delay may explain, at least in part, the delay in cytokinesis itself. Earlier studies had shown an association of microtubules with the cleavage furrow, and we used a fluorescently tagged EB1 protein to show that microtubules are still associated with the furrows in the absence of F-actin, consistent with the possibility that the microtubules are important for furrow formation. We suggest that the actomyosin ring evolved as one way to improve the efficiency of a core process for furrow formation that was already present in ancestral eukaryotes. |
| Databáze: | OpenAIRE |
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