Constriction imposed by basement membrane regulates developmental cell migration
The basement membrane (BM) is a specialized extracellular matrix (ECM), which underlies or encases developing tissues. Mechanical properties of encasing BMs have been shown to profoundly influence the shaping of associated tissues. Here, we use the migration of the border cells (BCs) of the Drosophila egg chamber to unravel a new role of encasing BMs in cell migration. BCs move between a group of cells, the nurse cells (NCs), that are enclosed by a monolayer of follicle cells (FCs), which is, in turn, surrounded by a BM, the follicle BM. We show that increasing or reducing the stiffness of the follicle BM, by altering laminins or type IV collagen levels, conversely affects BC migration speed and alters migration mode and dynamics. Follicle BM stiffness also controls pairwise NC and FC cortical tension. We propose that constraints imposed by the follicle BM influence NC and FC cortical tension, which, in turn, regulate BC migration. Encasing BMs emerge as key players in the regulation of collective cell migration during morphogenesis.
Acknowledgements: We acknowledge the Bloomington Stock Centre and the Developmental Studies Hybridoma Bank for fly stocks and antibodies. We also thank Sara Martín Villanueva and Marc Furriols for their help in generating the tslGFP construct and transgenic flies. Finally, we are grateful to A. González-Reyes for helpful remarks on the manuscript.
Ministerio de Ciencia, Innovación y Universidades (BFU2016-80797-R)
Fundación Pública Andaluza Progreso y Salud (P20_00888)