Mondo, J. A. | Search bioRxiv

bioRxiv2022

Specialized protrusions coordinate migratory border cell cluster cohesion via Scribble, Cdep, and Rac

Collective cell movements drive normal development and metastasis. Drosophila border cells move as a cluster of 6-10 cells, where the role of the Rac GTPase in migration was first established. Rac stimulates leading edge protrusions in most migratory cells. Upstream Rac regulators in leading border cell protrusions have been identified; however the regulation and function of Rac in follower cells is unknown. Here we show that Rac is required in all cells of the cluster and promotes follower cell motility. We identify a Rac guanine nucleotide exchange factor, Cdep, that also regulates follower cell movement and cluster cohesion. The tumor suppressors Scribble, Discs Large, and Lethal Giant Larva localize Cdep basolaterally and share phenotypes with Cdep. Relocalization of Cdep::GFP partially rescues Scrib knockdown, suggesting that Cdep is a major downstream effector of basolateral proteins. Thus, a Scrib/Cdep/Rac pathway promotes cell crawling and coordinated, collective migration in vivo.

cell biology↗

bioRxiv2020

Tissue topography steers migrating Drosophila border cells

Moving cells can sense and respond to physical features of the microenvironment, however in vivo the significance of tissue topography is mostly unknown. Here we use the Drosophila border cells, an established model for in vivo cell migration, to study how chemical and physical information influence migration path selection. Live imaging, genetics, modeling, and simulations show that, although chemical cues were thought to be sufficient, microtopography is also important. Chemoattractants promote predominantly posterior movement, whereas tissue architecture presents orthogonal information, a path of least resistance concentrated near the center of the egg chamber. E-cadherin supplies a permissive haptotactic cue. Our results provide insight into how cells integrate and prioritize topographical, adhesive, and chemoattractant cues to choose one path amongst many.

developmental biology↗