Development. 2021 Feb 26;148(4):dev195511. doi: 10.1242/dev.195511.
Véronique Van De Bor 1 , Vincent Loreau 2 , Marilyne Malbouyres 3 , Delphine Cerezo 2 , Audrey Placenti 2 , Florence Ruggiero 3 , Stéphane Noselli 1
1 Université Côte d’Azur, CNRS, Inserm, iBV, France firstname.lastname@example.org email@example.com.
2 Université Côte d’Azur, CNRS, Inserm, iBV, France.
3 Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon – CNRS UMR 5242 – INRA USC 1370, 46, allée d’Italie, 69364 Lyon cedex 07, France.
Basement membranes (BM) are extracellular matrices assembled into complex and highly organized networks essential for organ morphogenesis and function. However, little is known about the tissue origin of BM components and their dynamics in vivo Here, we unravel the assembly and role of the BM main component, Collagen type IV (ColIV), in Drosophila ovarian stalk morphogenesis. Stalks are short strings of cells assembled through cell intercalation that link adjacent follicles and maintain ovarian integrity. We show that stalk ColIV has multiple origins and is assembled following a regulated pattern leading to a unique BM organisation. Absence of ColIV leads to follicle fusion, as observed upon ablation of stalk cells. ColIV and integrins are both required to trigger cell intercalation and maintain mechanically strong cell-cell attachment within the stalk. These results show how the dynamic assembly of a mosaic BM controls complex tissue morphogenesis and integrity.