Signaling and Neural Crest Development

Forming a functional organism from a few stem cells is the challenge facing every embryo. The growth and early regionalization of an embryo require the precise orchestration in time and space of not only gene activity, but also a variety of post-transcriptional regulations. Understanding how the genetic programs that regulate embryo development, and in particular cell migration and morphogenesis, are encoded and regulated is a current challenge in developmental biology.

Our laboratory's efforts are focused on understanding the early stages in the formation of neural crest cells, which arise from the dorsal ectoderm during gastrulation and neurulation, then migrate throughout the developing embryo. These cells, which are characteristic of vertebrates and indispensable to the life of the embryo, raise questions about the multipotency of a population of embryonic "stem" cells, their controlled migration in time and space, and their differentiation. Defects in the formation of these cells and their derivatives are responsible for a quarter of all human congenital malformations, and many aggressive cancers, including melanoma.

The team's projects and collaborations focus on two major areas:

1- Identification of the gene network responsible for the emergence of the neural crest.

2- Understanding pathologies linked to dysfunction of this network during development or in cancers such as metastatic melanoma.

The early stages of neural development are evolutionarily conserved, specifically regionalization, growth and migration. Notably, the main components of the gene networks that orchestrate development are conserved. Our main study model is the amphibian embryo Xenopus laevis. These embryos are abundant, accessible to experimental manipulation and sophisticated molecular tools are available to study them. We use in vivo gene overexpression and loss-of-function approaches combined with explant studies. We have developed large-scale gene network strategies coupled with fine embryology strategies to establish the transcriptional network controlling early neural crest development. Thanks to the wide range of expertise represented in our group, we also use chicken embryos, mouse embryos and cells in culture. Our approaches range from whole-organism analysis in vivo to single-cell scale and modeling.