Laboratoire Interdisciplinaire de Physique
140 rue de la physique 38400 Saint Martin d’Hères
phone: +33 476 63 58 16
The central question of my research activity concerns the interactions between the living matter and its physical environment along two axes: FRET microscopy and active and cognitive matter. On the one hand, I am developing a method allowing the absolute measurement of the FRET phenomenon (energy transfer between fluorophores) on a standard epifluorescence microscope. The objectives of this part are: (i) to improve the accessibility and robustness of the existing method to better disseminate it; (ii) to extend the framework to allow the reliable measurement of inter-molecular biosensors and the measurement of stoichiometry in living cells. On the other hand, I propose an original experimental model to improve the understanding of collective phenomena in complex environments. The model is based on small fish swimming in a school that we subject to controlled environments (obstacles and flows). The objectives of this part are: (i) to propose a complete model including hydrodynamic and social interactions; (ii) to improve the understanding of collective behaviour and collective intelligence.
Keywords: Collective movements, active matter, Fluorescence microscopy, FRET
In a join work with Philippe Peyla (LIPhy), we are interested in the spontaneous emergence of an ordered movement in a system composed of a large number of individuals. This intriguing and almost universal phenomenon can be found in bacteria on a sub-millimetre scale, in schools of fish stretching for kilometres, in human crowds or in flocks of birds. These collective movements result from local interactions between individuals from which large-scale patterns emerge. We approach this topic in an original way by seeking to understand the effect of a complex physical environment (flows, obstacles) on the collective swimming behaviour of small aquarium fish (Blue Neon, Paracheirodon innesi). In particular, we aim to investigate the coupling between their social interactions and their hydrodynamic interactions, which have so far mainly been studied separately. To this end, we combine an experimental approach in a controlled environment providing quantitative measurements with a numerical approach coupling the direct resolution of the 3D hydrodynamics with a cognitive model in collaboration with Thibaut Métivet (INRIA).
coming soon: we are organising a workshop in Cargèse in May 2024 on collective movements in the living and in robots
Being able to measure the biochemical activity of a target protein in a living cell in a spatially and temporally resolved manner is quite a challenge. This is not possible with classical molecular biology methods, however, new tools have recently emerged, namely fluorescent biosensors. Most of them are based on the principle of "Förster Resonance Energy Transfer" (FRET), i.e. the transfer of energy between two fluorophores allowing to probe distances of the order of a few nanometers and thus changes in protein conformation. These biosensors have enormous potential but their development is hampered on the one hand by the difficulty to develop them and on the other hand by the difficulty of measuring FRET reliably in living cells. To unblock this last point,we developed a new method for measuring and quantitatively analysing FRET during Alexis Coullomb’s thesis, in collaboration with the teams of Don Lamb (LMU Munich) and Corinne Albigès-Rizo (IAB Grenoble). Starting again from the physical equations of fluorescence signal acquisition, we have refreshed the theoretical framework and proposed a new calibration method that allows the measurement of absolute FRET values and thus opening the way to new experiments. In addition, this method gives access to the relative stoichiometry between donor and acceptor molecules and hence allows the quantitative measurement of inter-molecular FRET biosensors (where the stoichiometry is not fixed).
|2013 - present||CNRS Researcher, LIPhy, Grenoble|
|2009-2013||Postdoc, LMU, Munich, Allemagne "3D single particle tracking, tracking of fluorescent viruses in living cells. " Don C Lamb team, Physical chemistry Dpt, LMU|
|2005-2008||PhD student, Université Paris Diderot, Institut Curie, Paris "Homologous recombination on a single DNA molecule: torsion and torque measurements. " Supervision J.-L. Viovy and G. Cappello. Physico-chimie Curie.|
|June 2017||Habilitation à diriger des recherches, UGA, Grenoble|
|Nov. 2008||PhD in biophysics, Univ. Paris Diderot|
|2004-2005||Master 2 Interfaces physique-biologie, Paris 11/Paris7|
|2002-2004||Licence et M1 physics, ENS Lyon|
|2021-||PhD co-supervision of Océane Terral, supervised by Cécile Delacour (I. Néel), UGA, Grenoble|
|2020-||PhD supervision of Renaud Larrieu, shared with Philippe Peyla (LIPhy), UGA, Grenoble|
|2017-2020||PhD supervision of Alain Lombard, UGA, Grenoble|
|2015-2018||PhD supervision of Alexis Coullomb, UGA, Grenobl|
|2014-2017||Supervision of 2 post-docs, C Bidan (36 months) et S Sultana (12 months)|