1 research outputs found
Gα12/13 regulate epiboly by inhibiting E-cadherin activity and modulating the actin cytoskeleton
Epiboly spreads and thins the blastoderm over the yolk cell during zebrafish
gastrulation, and involves coordinated movements of several cell layers.
Although recent studies have begun to elucidate the processes that underlie
these epibolic movements, the cellular and molecular mechanisms involved remain
to be fully defined. Here, we show that gastrulae with altered
Gα12/13 signaling display delayed epibolic movement of
the deep cells, abnormal movement of dorsal forerunner cells, and dissociation
of cells from the blastoderm, phenocopying e-cadherin mutants.
Biochemical and genetic studies indicate that Gα12/13
regulate epiboly, in part by associating with the cytoplasmic terminus of
E-cadherin, and thereby inhibiting E-cadherin activity and cell adhesion.
Furthermore, we demonstrate that Gα12/13 modulate epibolic
movements of the enveloping layer by regulating actin cytoskeleton organization
through a RhoGEF/Rho-dependent pathway. These results provide the first in vivo
evidence that Gα12/13 regulate epiboly through two distinct
mechanisms: limiting E-cadherin activity and modulating the organization of the
actin cytoskeleton