Nuclei as mechanical bumpers during epithelial remodeling.

Area of Science:

• Developmental Biology
• Cell Biology
• Biophysics

Background:

• Tissue morphogenesis involves cellular rearrangements, with cell intercalation driving elongation.
• Current research often overlooks the nucleus's role in cell shape changes during tissue remodeling.

Purpose of the Study:

• To investigate how nuclear properties influence cell shaping and tissue elongation dynamics.
• To understand the mechanisms cells employ to manage internuclear tensions.

Main Methods:

• Analysis of pulsed contractile and extension dynamics in elongating Drosophila embryos.
• Observation of nuclear deformation and dispersion in response to tissue remodeling forces.

Main Results:

• Tightly packed nuclei impede tissue remodeling and oscillatory behaviors.
• Nuclear deformation and dispersion are key mechanisms for resolving internuclear tensions.
• Disrupting these mechanisms leads to severe tissue extension defects and cell extrusion.

Conclusions:

• Nuclear shape and positioning are critical for topological remodeling in epithelia.
• The nucleus actively participates in tissue morphogenesis, not just passively responds to forces.