A novel mechanism of bulk cytoplasmic transport by cortical dynein in Drosophila ovary
Abstract
Cytoplasmic dynein, a major minus-end directed microtubule motor, plays essential roles in eukaryotic cells. Drosophila oocyte growth is mainly dependent on the contribution of cytoplasmic contents from the interconnected sister cells, nurse cells. We have previously shown that cytoplasmic dynein is required for Drosophila oocyte growth and assumed that it simply transports cargoes along microtubule tracks from nurse cells to the oocyte. Here we report that instead of transporting individual cargoes along stationary microtubules into the oocyte, cortical dynein actively moves microtubules within nurse cells and from nurse cells to the oocyte via the cytoplasmic bridges, the ring canals. This robust microtubule movement is sufficient to drag even inert cytoplasmic particles through the ring canals to the oocyte. Furthermore, replacing dynein with a minus-end directed plant kinesin linked to the actin cortex is sufficient for transporting organelles and cytoplasm to the oocyte and driving its growth. These experiments show that cortical dynein performs bulk cytoplasmic transport by gliding microtubules along the cell cortex and through the ring canals to the oocyte. We propose that the dynein-driven microtubule flow could serve as a novel mode of fast cytoplasmic transport.
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All data generated or analyzed during this study are included in the manuscript and supporting file; Source Data files have been provided for Figure 5.
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Funding
National Institute of General Medical Sciences (R35 GM131752)
- Vladimir I Gelfand
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2022, Lu et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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