Researchers from the IRIBHM (ULB) recently published a study in Nature in collaboration with the University of Cambridge. They clarify a key stage of embryonic development : gastrulation.
Wallis Nahaboo, Diana Suarez Boomgaard, Isabelle Migeotte (WELBIO 2015-2019) and their colleagues from Cambridge investigated gastrulation in mice embryo models. It is during gastrulation that the 3 cell layers are formed, from which all tissues and organs originate: the endoderm, the mesoderm and the ectoderm. They form via an epithelial mesenchymal transition at the primitive streak, a subpopulation of the epiblast, specified on the posterior side of the embryonic cylinder.
In their study, the researchers demonstrate that, for the gastrulation to take place, the basal membrane separating the germinal layers (epiblast and visceral endoderm) needs to be perforated by metalloproteases under the control of the Nodal signalling pathway.
The data show that a mechanical modification, the weakening of the basal membrane, is required for growth and morphogenesis of the embryo, as well as for gastrulation. This is important conceptually but also practically. In particular, protocols can be improved for the production of synthetic embryo models from stem cell lines, a very useful tool for testing hypothesis in developmental biology while limiting the use of animal embryos.
The contribution from the ULB was related to the production of mutant embryos with an abnormal primitive streak, which were instrumental for confirming the correlation between basal membrane perforations and gastrulation.
Source : ULB
Picture provided by ULB
Référence : Kyprianou, C., Christodoulou, N., Hamilton, R. S., Nahaboo, W., Boomgaard, D. S., Amadei, G., Migeotte, I. & Zernicka-Goetz, M. (2020). Basement membrane remodelling regulates mouse embryogenesis. Nature, (March 2019). https://doi.org/10.1038/s41586-020-2264-2