Developing embryos achieve morphogenesis by exploiting cellular forces in a coordinated and oriented manner to generate deformations leading to shape acquisition. In addition to the space–time controlled execution of the genetic programme, this also requires to harness the potential of the embryo's 3D geometry to localise and orient mechanical forces. We have recently shown [Fierling et al, 2022] how 3D geometry of the Drosophila embryo is responsible for the anisotropy of mechanical stress, which in turn fold the tissue in a rectilinear way during initial ventral furrow formation, see Fig 1A.
For the internship, the objective is to carry groundwork for the understanding of the following phase in embryo gastrulation, when the furrow invaginates. Based on experiments ongoing at IBV, and in collaboration with the team in LIPHY, the intern will use numerical and/or analytical approaches to identify the best suited mechanical model to explain observations.
For the PhD, the objective is to implement this model during the first year at LIPHY and to perform simulatenously numerical simulations and experiments at iBV from the second year on. See the PDF of the PhD offer.
IBV researchers have developed imaging techniques and revealed cytoskeletal structures at the lateral and basal levels in cells, that is, tens of microns deep into the embryo [John & Rauzi, 2021] : those are little known yet due to imaging difficulties. They are also able to test their mechanical behaviour. Specifically, laser ablations (nano-surgery cuts revealing the mechanical tension) and optogenetics (local and controlled activation of molecular motors) will allow us to have a “reverse engineering” approach of the system.
Numerical simulations can be based on existing tools such as Surface Evolver in 3D [Fierling et al, 2022] and ACAM in 2D, co-developed by LIPHY [Nestor-Bergmann et al, 2022].
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For the internship:
- Modelling at LIPHY (Grenoble) supervised by Jocelyn Etienne and Catherine Quilliet, using analytical/numerical methods.
- Monthly internship allowance: 543,60 €.
- 5 to 6 months duration.
- PhD follow-up preferred.
Requisites:
- Physics or engineering student with an interest for complex matter.
- Programming in python.
- No biology prerequisite.
