Primordial germ cells adjust their protrusion type while migrating in different tissue contexts in vivo

Abstract

In both physiological processes and disease contexts, migrating cells have the ability to adapt to conditions in their environment. As an in vivo model for this process, we use zebrafish primordial germ cells that migrate throughout the developing embryo. When migrating within an ectodermal environment, the germ cells form fewer and smaller blebs as compared with their behavior within mesodermal environment. We find that cortical tension of neighboring cells is a parameter that affects blebbing frequency. Interestingly, the change in blebbing activity is accompanied by the formation of more actin-rich protrusions. These alterations in cell behavior that correlate with changes in RhoA activity could allow the cells to maintain dynamic motility parameters, such as migration speed and track straightness, in different settings. In addition, we find that the polarity of the cells can be affected by stiff structures positioned in their migration path.

Luteinizing hormone stimulates ingression of mural granulosa cells within the mouse preovulatory follicle

“…Alternatively, the cellular processes connecting these cell bodies to the basal lamina might have been too thin to see with light microscopy or might not have been contained within the 10 µm thick section. These cells often had numerous filopodia extending in many directions, as well as membrane blebs (Figure 3D,E), consistent with the presence of filopodia and blebs on other migratory cells [44][45][46].…”

The journey of a generation: advances and promises in the study of primordial germ cell migration

“…However, much of the current data are correlative in nature, and functional perturbations of PGC–ECM interactions in mice, fish, quails and flies, either through integrin ablation, matrix metalloprotease inhibition or ECM mutants, show only modest or no impairment of migration ( Carver et al, 2021 ; Ismat et al, 2013 ; Huss et al, 2019 ; Anderson et al, 1999 ; Devenport and Brown, 2004 ; Kardash et al, 2010 ; Jaglarz and Howard, 1995 ). Collectively, these results indicate that PGCs may use other ECM receptors for migration, such as syndecans or discoidin domain receptors ( Table 1 ) or that the ECM may play a more permissive role in creating an ideal mechanical environment for migration ( Truszkowski et al, 2023 ). Yet another possibility is that PGCs may utilize a friction-based migration strategy that does not require specific adhesion (see below).…”

“…3A ). Zebrafish PGCs can also extend mesenchymal-like, actin-filled pseudopods, but predominantly generate blebs unless surrounded by cells with high cortical tension ( Truszkowski et al, 2023 ). Bleb generation likely reflects the PGC's internal state of actomyosin contractility, as isolated zebrafish PGCs continuously generate blebs when ­placed on glass coated with different ECM compositions or in a 3D Matrigel environment ( Blaser et al, 2006 ).…”