Expanding Actin Rings Zipper the Mouse Embryo for Blastocyst Formation.
Cell
; 173(3): 776-791.e17, 2018 04 19.
Article
em En
| MEDLINE
| ID: mdl-29576449
ABSTRACT
Transformation from morula to blastocyst is a defining event of preimplantation embryo development. During this transition, the embryo must establish a paracellular permeability barrier to enable expansion of the blastocyst cavity. Here, using live imaging of mouse embryos, we reveal an actin-zippering mechanism driving this embryo sealing. Preceding blastocyst stage, a cortical F-actin ring assembles at the apical pole of the embryo's outer cells. The ring structure forms when cortical actin flows encounter a network of polar microtubules that exclude F-actin. Unlike stereotypical actin rings, the actin rings of the mouse embryo are not contractile, but instead, they expand to the cell-cell junctions. Here, they couple to the junctions by recruiting and stabilizing adherens and tight junction components. Coupling of the actin rings triggers localized myosin II accumulation, and it initiates a tension-dependent zippering mechanism along the junctions that is required to seal the embryo for blastocyst formation.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Limite:
Animals
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article