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Active nuclear positioning and actomyosin contractility maintain leader cell integrity during gonadogenesis
Priti Agarwal1, Simon Berger2, Tom Shemesh3
1Department of Cell and Developmental Biology, Faculty of Medical & Health Sciences, Tel Aviv University, Tel Aviv 6997801, Israel.
Current Biology : CB
|May 22, 2024
Summary
The nucleus
Area of Science:
- Cell biology
- Developmental biology
- Biophysics
Background:
- Proper organelle distribution is crucial for cell motility.
- The nucleus of the Caenorhabditis elegans distal tip cell (DTC) is front-localized during gonad morphogenesis, but the reason is unclear.
Purpose of the Study:
- To elucidate the molecular mechanism maintaining nuclear positioning in the DTC.
- To investigate the functional significance of nuclear positioning during C. elegans gonad development.
Main Methods:
- Identified the KASH protein UNC-83 as a linker between the nucleus and kinesin-1.
- Utilized genetic knockdowns and live imaging to observe effects of disrupted nuclear positioning and actomyosin contractility.
- Developed a biophysical model to understand cell mechanics.
Main Results:
- UNC-83 links the nucleus to kinesin-1 for active nuclear positioning.
- Disrupting nuclear positioning alone had no effect on gonad morphogenesis.
- Combined nuclear mispositioning with reduced actomyosin contractility caused DTC splitting and gonad bifurcation.
- Fragmentation of the DTC into nucleated and enucleated cells was observed during U-turns.
- Enucleated cytoplasts showed temporary germ cell support.
Conclusions:
- The leader cell uses both active nuclear positioning (via microtubule motors) and actomyosin contractility for integrity and morphogenesis.
- These complementary mechanical strategies enable navigation in complex 3D environments.
- Nuclear positioning is essential for preventing cell fragmentation during C. elegans gonad development.
Keywords:
C. elegansLINC complexcell migrationcytoskeletondevelopmentgonadmechanobiologymicrotubulesmorphogenesisnucleusMore Related Videos
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