Interplay between the dividing cell and its neighbors temporally and spatially regulates adherens junction formation during cytokinesis in epithelial tissue. Sophie Herszterg¹, Andrea Leibfried², Floris Bosveld¹, Charlotte Martin¹, Yohanns Bellaiche¹. 1) Polarity Division and Morphogenesis Team, Institut Curie, CNRS UMR 3215, INSERM U934, 26 rue dUlm, 75248 Paris Cedex 05, France; 2) Present address: Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.

   Epithelial tissue proliferation requires the formation of new adherens junctions (AJs) to maintain tissue polarity, integrity and architecture. How AJs are formed upon cell division is largely unexplored. We found that AJ formation is coordinated with cytokinesis and relies on an interplay between the dividing cell and its neighbors. During the contraction of the cytokinetic ring, the neighboring cells locally accumulate Myosin II and produce the cortical tension necessary to set the initial geometry of the daughter cell interface. Yet, the neighboring cell membranes impede AJ formation. Upon midbody formation and concomitantly to neighboring cell withdrawal, Arp2/3-dependent F-actin polymerization oriented by the midbody maintains AJ geometry and regulates AJ final length and the epithelial cell arrangement upon division. We propose that cytokinesis in epithelia is a multicellular process, whereby the cooperative actions of the dividing cell and its neighbors define a two-tiered mechanism that spatially and temporally controls AJ formation while maintaining tissue cohesiveness.