Abstract

The control of cell shape during cytokinesis requires a precise regulation of mechanical properties of the cell cortex. Only few studies have addressed the mechanisms underlying the robust production of unequal-sized daughters during asymmetric cell division and, in particular, the mechanisms that ensure cell division is a mechanically stable process. In particular, Laplace pressure gradients inside the dividing cell generally tend to destabilize the cell surface, an effect that will be even more pronounced when cells divide in an asymmetric fashion. Experiments with asymmetrically dividing sensory organ precursor (SOP) cells in Drosophila show that modifications of relative amounts of branched Actin in the two daughter cells during division are sufficient to engineer essentially arbitrary daughter-size asymmetries. Following this observation, we introduce a minimal model of the division process that reveals cortical bending rigidity as a crucial ingredient to quantitatively explain both the observed size asymmetries in SOP daughter cells, as well as the mechanical stability of the underlying division process.