Biophysical Society Thematic Meeting| Aussois 2019

Biology and Physics Confront Cell-Cell Adhesion

Poster Abstracts

6-POS Board 6 BIOLOGICAL AND PHYSICAL BASIS FOR EPITHELIAL CELL REINTEGRATION Christian Cammarota 1 ; Colleen Mallie 2 ; Tyler Wilson 2 ; Nicole Dawney 2 ; David Q Matus 3 ; Dan Bergstralh 1,2 ; 3 Stony Brook University, Biochemistry and Cell Biology, Stony Brook, NY, USA Proliferating epithelia face a challenge: dividing cells must increase in size despite spatial constraints presented by their neighbors. Mitotic epithelial cells often move apically, likely as a way to escape epithelial confinement by extending into the third dimension. The resulting daughter cells must subsequently reintegrate into the tissue so that proper tissue architecture is maintained. Reintegration is a poorly understood process, and we are using the Drosophila follicular epithelium to investigate the physical and biological driving forces behind it. A suite of lateral Ig-superfamily adhesion proteins, named Neuroglian, Fasciclin 2, and Fasciclin 3 in the fly, are integral to reintegration. We have determined that these Ig-superfamily adhesion proteins work in parallel rather than as steps in a linear pathway, suggesting that reintegration is an effect of total cell-cell adhesion. Intracellular binding of these proteins also plays a key role in reintegration, likely by allowing force transmission to the cytoskeleton. We propose that the function of these proteins is to build an anchored track that reintegrating cells can adhere to. This adhesion provides the force necessary to reinsert an apically positioned daughter cell into the tissue. Furthermore, our work in non-fly models suggests that this set of proteins and their role in reintegration may be conserved throughout proliferative epithelia. 1 University of Rochester, Physics, Rochester, NY, USA 2 University of Rochester, Biology, Rochester, NY, USA

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