Basal delamination during mouse gastrulation primes pluripotent cells for differentiation

Area of Science:

• Developmental biology
• Cell biology
• Genetics

Background:

• Mammalian body plan formation occurs during gastrulation, involving epiblast cell proliferation and ingression.
• The coordination of proliferation, ingression, and cell fate specification during gastrulation is not fully understood.

Purpose of the Study:

• To investigate the coordination between cell proliferation, ingression, and differentiation during mouse gastrulation.
• To elucidate the mechanisms linking cell crowding to primitive streak fate specification.

Main Methods:

• Development and characterization of a 3D culture of self-renewing mouse embryonic cells.
• Integration of microfabrication techniques and in vivo experiments.
• Analysis of cell delamination, Wnt signaling sensitivity, and primitive streak marker expression.

Main Results:

• Proliferation-induced crowding triggers the delamination of cells expressing high levels of aPKC (atypical protein kinase C).
• Delaminated cells exhibit increased sensitivity to Wnt signaling.
• Upregulation of primitive streak markers, such as Brachyury, occurs upon delamination.

Conclusions:

• A mechanistic link exists between cell ingression and differentiation during gastrulation.
• Crowding-induced delamination and subsequent Wnt signaling sensitivity ensure proper cell type specification in the developing embryo.