Neighbor cells restrain furrowing during epithelial cytokinesis.

Area of Science:

• Cell Biology
• Developmental Biology
• Biophysics

Background:

• Cytokinesis, the process of cell division, generates forces that can disrupt tissue integrity.
• Epithelial cells are connected by cell-cell junctions, which may resist these forces.
• Previous studies indicated junction reinforcement influences furrowing speed in Xenopus laevis epithelia.

Purpose of the Study:

• To investigate the role of neighboring epithelial cells in regulating cytokinesis.
• To determine how mechanical forces from adjacent cells affect the division process.
• To understand the balance between forces generated during cell division and resisting forces from neighbors.

Main Methods:

• Observing accumulation of contractility factors in neighboring cells during cytokinesis.
• Modulating neighbor cell stiffness via alpha-actinin overexpression.
• Using optogenetics to control neighbor cell contractility (Rho activation).
• Analyzing the effects on furrowing speed, pausing, and completion.

Main Results:

• Contractility factors accumulate in neighboring cells near the cytokinetic furrow.
• Increased neighbor cell stiffness or contractility slowed or paused furrowing.
• Optogenetic activation of contractility on both sides of the furrow caused complete cytokinetic failure and binucleation.

Conclusions:

• Neighboring cells exert mechanical forces that balance the forces from the cytokinetic array.
• Neighbor cell mechanics are critical regulators of cytokinesis speed and fidelity.
• Disruption of this mechanical balance can lead to failed cell division.