Tissue tension and not interphase cell shape determines cell division orientation in the Drosophila follicular epithelium

We examined the orientation of cell divisions with respect to the planar tissue axis and found a bias toward the primary direction of tissue expansion. However, interphase cell shapes demonstrate the opposite bias. Hertwig's rule, which holds that cell elongation determines division orientation, is therefore broken in this tissue. This observation cannot be explained by the anisotropic activity of the conserved Pins/Mud spindle-orienting machinery, which controls division orientation in the apical–basal axis and planar division orientation in other epithelial tissues. Rather, cortical tension at the apical surface translates into planar division orientation in a manner dependent on Canoe/Afadin, which links actomyosin to adherens junctions. These findings demonstrate that division orientation in different axes—apical–basal and planar—is controlled by distinct, independent mechanisms in a proliferating epithelium.

Source: EMBO Journal - February 1, 2019 Category: Molecular Biology Authors: Finegan, T. M., Na, D., Cammarota, C., Skeeters, A. V., Nadasi, T. J., Dawney, N. S., Fletcher, A. G., Oakes, P. W., Bergstralh, D. T. Tags: Cell Adhesion, Polarity & Cytoskeleton, Development & Differentiation Articles Source Type: research