We have previously shown that the early embryo in birds exhibits a surprising mechanical response to forces: it behaves like an elastic in response to isotropic stresses and it flows like a fluid in response to shear stresses. In addition, these two responses can coexist within the same tissue, leading to a superposition of the two behaviors. The goal of this internship is to characterize the cellular mechanisms that control these responses. To do so, the intern will develop new mechanical perturbations using a micromanipulator developed in the lab and will study their impact by confocal microscopy. The internship will be supervised by Arthur Michaut, a CNRS researcher in the team who developed the micromanipulator. The intern needs to have a strong interest in interdisciplinary and experimental approaches.