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 Galpha(12/13) 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 Galpha(12/13) 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 Galpha(12/13) 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 Galpha(12/13) regulate epiboly through two distinct mechanisms: limiting E-cadherin activity and modulating the organization of the actin cytoskeleton.
Pubmed ID: 19307601 RIS Download
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Image analysis software package that allows non-destructive image marking, input for further image processing, and marking the results of automatic measurements. Object-Image integrates measurements, macros, graphical objects and image names in a closed unit called 'object file' so that it reduces file clutter.
View all literature mentionsCell line HEK293 is a Transformed cell line with a species of origin Homo sapiens (Human)
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