Active chiral flows in the separating wall during cell division.

This article investigates the influence of active chiral torques on the material flow within the actomyosin cortex during cell division, specifically focusing on the growing annular-shaped intracellular membrane partition that divides the cell. Using hydrodynamic theory of active gels, the study predicts that intrinsic molecular chirality can induce nonzero azimuthal (rotational) velocity components in the partition's flow, with the direction of rotation depending not only on the sign of the active chiral torque but also on the interplay between rotational viscosity and flow coupling parameters. Numerical solutions reveal that chiral active stresses alone can generate azimuthal flows even without external torque or asymmetric boundary conditions, and that the azimuthal flow may reverse direction radially within the partition. The findings highlight that molecular-level chirality does not uniquely determine flow direction, which instead emerges from complex coupling of physical parameters, and suggest that experimental verification requires high-resolution imaging of cell division interfaces.