Jean-Léon Maître Understanding the influence of mechanical forces on embryonic cell development

Measuring the forces that give shape to life

During embryonic development, cells use the information in their genes to form the organism. This leads to a series of events in which cells divide, die, become deformed and move. Jean-Léon Maître measures and studies mechanical forces to understand their impact on cell and embryonic development.

He and his team are examining the first steps in the development of the mouse embryo, even before its implantation in the uterus. Their current focus is the trophectoderm, the mammalian embryo’s first epithelium. The trophectoderm, which later becomes the placenta, surrounds a pocket of liquid called lumen and a group of cells that will generate all the embryo’s tissues. The trophectoderm stretches as the embryo grows, deforming not only the cells that make it up but also their nuclei, which contain all the genetic information.

Dr. Maître will ask three questions to understand the mechanisms that allow these cells to stretch and their consequences:

- How do trophectoderm cells increase their surface area while stretching? - How does the cell nucleus flatten out and what are the consequences for genetic expression? - How do cell stretching and nuclear deformation affect the trophectoderm’s future and the embryo’s implantation in the uterus?

The foundation’s support

The Bettencourt Prize to Boost French Research will allow the laboratory to acquire an optical tweezer system to measure and change the forces acting on cells in early-stage embryo development. The system involves using a laser to handle microscopic elements such as cells and nuclei.

The device, combined with a powerful microscope with an incubation system to grow mammal embryos, will be the only one in France.