Nat Commun. 2020 Apr 21;11(1):1921. doi: 10.1038/s41467-020-15593-2.
Anna Popkova1,2, Orrin J Stone3, Lin Chen1,4, Xiang Qin1,5, Chang Liu1,6, Jiaying Liu1, Karine Belguise1, Denise J Montell7, Klaus M Hahn3, Matteo Rauzi8, Xiaobo Wang9
1 LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France.
2 Université Côte d’Azur, CNRS, Inserm, iBV, Nice, France.
3 Department of Pharmacology and Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
4 Department of Anesthesia, Southwest Hospital, Third Military Medical University, 400038, Chongqing, People’s Republic of China.
5 Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, 610054, Chengdu, Sichuan, People’s Republic of China.
6 Department of Anaesthesia, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, 430014, Wuhan, Hubei, People’s Republic of China.
7 Molecular, Cellular and Developmental Biology Department, University of California, Santa Barbara, CA, USA.
8 Université Côte d’Azur, CNRS, Inserm, iBV, Nice, France. firstname.lastname@example.org.
9 LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062, Toulouse, France. email@example.com.
Actomyosin supracellular networks emerge during development and tissue repair. These cytoskeletal structures are able to generate large scale forces that can extensively remodel epithelia driving tissue buckling, closure and extension. How supracellular networks emerge, are controlled and mechanically work still remain elusive. During Drosophila oogenesis, the egg chamber elongates along the anterior-posterior axis. Here we show that a dorsal-ventral polarized supracellular F-actin network, running around the egg chamber on the basal side of follicle cells, emerges from polarized intercellular filopodia that radiate from basal stress fibers and extend penetrating neighboring cell cortexes. Filopodia can be mechanosensitive and function as cell-cell anchoring sites. The small GTPase Cdc42 governs the formation and distribution of intercellular filopodia and stress fibers in follicle cells. Finally, our study shows that a Cdc42-dependent supracellular cytoskeletal network provides a scaffold integrating local oscillatory actomyosin contractions at the tissue scale to drive global polarized forces and tissue elongation.