Reassessing the Role and Dynamics of Nonmuscle Myosin II during Furrow Formation in EarlyDrosophilaEmbryos
| Autor: | Christine M. Field, Roger E. Karess, John C. Sisson, William J. Sullivan, Anne Royou |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Embryo
Nonmammalian animal structures Green Fluorescent Proteins macromolecular substances Biology Membrane Fusion Myosin Animals Drosophila Proteins Cleavage furrow Cytoskeleton Molecular Biology Actin Membrane invagination Myosin Type II Microscopy Confocal Articles Cell Biology Actin cytoskeleton Actins Cell biology Luminescent Proteins Drosophila melanogaster embryonic structures Cellularization Colchicine Cell Division Cytokinesis |
| Zdroj: | Molecular Biology of the Cell. 15:838-850 |
| ISSN: | 1939-4586 1059-1524 |
| DOI: | 10.1091/mbc.e03-06-0440 |
| Popis: | The early Drosophila embryo undergoes two distinct membrane invagination events believed to be mechanistically related to cytokinesis: metaphase furrow formation and cellularization. Both involve actin cytoskeleton rearrangements, and both have myosin II at or near the forming furrow. Actin and myosin are thought to provide the force driving membrane invagination; however, membrane addition is also important. We have examined the role of myosin during these events in living embryos, with a fully functional myosin regulatory light-chain-GFP chimera. We find that furrow invagination during metaphase and cellularization occurs even when myosin activity has been experimentally perturbed. In contrast, the basal closure of the cellularization furrows and the first cytokinesis after cellularization are highly dependent on myosin. Strikingly, when ingression of the cellularization furrow is experimentally inhibited by colchicine treatment, basal closure still occurs at the appropriate time, suggesting that it is regulated independently of earlier cellularization events. We have also identified a previously unrecognized reservoir of particulate myosin that is recruited basally into the invaginating furrow in a microfilament-independent and microtubule-dependent manner. We suggest that cellularization can be divided into two distinct processes: furrow ingression, driven by microtubule mediated vesicle delivery, and basal closure, which is mediated by actin/myosin based constriction. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|