Mouse primitive streak forms in situ by initiation of epithelial to mesenchymal transition without migration of a cell population
Open Access
- 6 December 2011
- journal article
- research article
- Published by Wiley in Developmental Dynamics
- Vol. 241 (2), 270-283
- https://doi.org/10.1002/dvdy.23711
Abstract
Background: During gastrulation, an embryo acquires the three primordial germ layers that will give rise to all of the tissues in the body. In amniote embryos, this process occurs via an epithelial to mesenchymal transition (EMT) of epiblast cells at the primitive streak. Although the primitive streak is vital to development, many aspects of how it forms and functions remain poorly understood. Results: Using live, 4 dimensional imaging and immunohistochemistry, we have shown that the posterior epiblast of the pre‐streak murine embryo does not display convergence and extension behavior or large scale migration or rearrangement of a cell population. Instead, the primitive streak develops in situ and elongates by progressive initiation EMT in the posterior epiblast. Loss of basal lamina (BL) is the first step of this EMT, and is strictly correlated with ingression of nascent mesoderm. Once the BL is lost in a given region, cells leave the epiblast by apical constriction in order to enter the primitive streak. Conclusions: This is the first description of dynamic cell behavior during primitive streak formation in the mouse embryo, and reveals mechanisms that are quite distinct from those observed in other amniote model systems. Unlike chick and rabbit, the murine primitive streak arises in situ by progressive initiation of EMT beginning in the posterior epiblast, without large‐scale movement or convergence and extension of epiblast cells. Developmental Dynamics 241:270–283, 2012.Keywords
This publication has 63 references indexed in Scilit:
- Reciprocal Repression between Sox3 and Snail Transcription Factors Defines Embryonic Territories at GastrulationDevelopmental Cell, 2011
- FGF signalling through RAS/MAPK and PI3K pathways regulates cell movement and gene expression in the chicken primitive streak without affecting E-cadherin expressionBMC Developmental Biology, 2011
- PTK7 is essential for polarized cell motility and convergent extension during mouse gastrulationDevelopment, 2009
- Genetic ablation of FLRT3 reveals a novel morphogenetic function for the anterior visceral endoderm in suppressing mesoderm differentiationGenes & Development, 2008
- Non-canonical Wnt signaling through Wnt5a/b and a novel Wnt11 gene, Wnt11b, regulates cell migration during avian gastrulationDevelopmental Biology, 2008
- The migration of paraxial and lateral plate mesoderm cells emerging from the late primitive streak is controlled by different Wnt signalsBMC Developmental Biology, 2008
- Wnt3a-mediated chemorepulsion controls movement patterns of cardiac progenitors and requires RhoA functionDevelopment, 2008
- Cell movement during chick primitive streak formationDevelopmental Biology, 2006
- PTK7/CCK-4 is a novel regulator of planar cell polarity in vertebratesNature, 2004
- Conditional activation of RhoA suppresses the epithelial to mesenchymal transition at the primitive streak during mouse gastrulationBiochemical and Biophysical Research Communications, 2004