On the 1st of July 2024, René Marc Mège officially joined the France-BioImaging team as Scientific Director. René Marc is a CNRS research director and co-director of the interdisciplinary Biology/Physics “Adhesion and Cell Mechanics” team with Benoit Ladoux at Institut Jacques Monod, Paris. He has been involved in the coordination of core facilities for more than ten years as co-director of the ImagoSeine cell imaging facility and leads the coordination of France-BioImaging Paris Centre Node.
Here is a brief interview to get to know the new leader of the FBI team.
- What triggered the start of your journey in science?
Actually, science was not my first choice. I would have loved to be a farmer like my parents. But part of this choice lies in the fact that I have always been amazed by nature and then by biology when arriving at Université de Bordeaux. At that time, I discovered and loved the essay “Le hazard et la nécessité” by Jacques Monod, published a decade before, in 1970. The second reason was that I thought that there would be some place for freedom in the job. It was true, at least at the time.
- Can you tell us a bit more about your scholar and research background?
I was trained in Biochemistry/Chemistry at the Université de Bordeaux. I began my scientific career in the field of enzymology and biotechnology with a PhD (1986) in D. Thomas Laboratoire de Technologie Enzymatique (Université de Technologie de Compiègne), where my thesis project was part of a heterogeneous-phase enzymatic catalysis research program aimed at assessing the industrial application of biological catalysts (hydrogenases) to convert electricity in hydrogen. After this PhD, I turned to the field of cell and developmental biology. I really got into this field during a 3-year postdoctoral fellowship (1987-1989) in G. M. Edelman laboratory at Rockefeller University, New York.
- Can you tell us about your work at IJM, and how it has influenced your journey as a researcher?
On my return to France, I focused on the expression, developmental role and function of cadherins in neuromuscular development. In the 2000’s, I shifted towards a more molecular and biophysical study of cadherin-dependent interactions, echoing the development of increasingly powerful imaging and analysis approaches. To this end, we developed a model for the activation of cadherin in the absence of intercellular contacts, based on the use of recombinant cadherins immobilised on various surfaces. By combining dynamic imaging, single particle tracking, FRAP and pharmacology (in coll with D. Choquet), we have shown that: 1) cadherin engagement induces their clustering and anchoring to the actin cytoskeleton; 2) that cadherins are recruited to cell contacts by a diffusion- trapping mechanism, regulated by their association with actin.
As early as 2002, this work enabled us to put forward the hypothesis – totally novel at the time – that cadherins could be mechanotransducing receptors. I therefore approached Benoit Ladoux, who had just developed a micro force sensor for measuring the forces applied by cells on the ECM. Combining this sensor with the use of recombinant cadherins, we were able to demonstrate that cadherin adhesions transmit across the membrane the forces generated actomyosin and are mechanosensitive, implying the existence of a molecular mechanosensor in these actin-associated complexes.
This work and hypotheses were the primary motivation behind the intensification of our collaboration with Benoit Ladoux, which led us to create in 2013 at the Institut Jacques Monod a shared team gathering cell biologists and physicists. We were both convinced that the only way to make significant progress in mechanobiology was not to recruit researchers at the interface, but to bring together researchers, post-docs and students trained at the cutting edge of their respective disciplines, with a willingness to work together. Together we have contributed to a better understanding of the molecular and cellular biology of cadherin-associated intercellular junctions, using microscopy-based approaches including traction force microscopy, stress inference, particle imaging velocimetry and high resolution microscopy.
From then, by combining our combined expertise in cell biology, microfabrication, biophysics and soft matter physics, we have been also able to develop innovative studies to describe the biomechanical properties of epithelial tissues and model them in collaboration with teams of theorists.
- You are now the new Director of France-BioImaging. Can you tell us what motivated this transition?
For many years, first at Sorbonne Université then at Université Paris-Cité, I have taken part in the coordination of the local Imaging Facilities. And during the last years, I have been more involved in France-BioImaging as head of the Paris-Centre node. Although I always dedicated time to the scientific and in particular, to the imaging community, I think I am now at an age where I should share even more of my time for the community. I am very convinced that the time and effort you devote to others always rewards you.
- What do you expect from this new professional adventure?
It is a new challenge and quite stimulating for me. Moreover, the FBI community is a very friendly and cooperative one.
- Can you tell us how research infrastructures like FBI can help researchers?
FBI core facilities and R&D teams offer an amazing large range of cutting-edge technologies, instruments, workflows, and pool of skills. FBI is a huge instrument. It’s however a living organism. Its heart is human-based, with its community of engineers, researchers, teachers and students, with their skills and competences, their personalities and collaborations, gives FBI its unique value. In the end, when researchers looking for imaging solutions know how to take advantage of the research infrastructures for their projects, they are able to increase their competitiveness in the global research race.
- What do you envision for FBI in the next few years?
The creation of the Unité d’Appui à la Recherche (UAR FBI-core) initiated by Edouard Bertrand and Alexandre Philips, and the previous national coordination team (we should thank them all here) will for sure participate to strengthen and bring more sustainability to FBI . This will allow us to concentrate our efforts on leading the community organisation initiatives and seeking new funding opportunities. This will also allow us to dedicate more resources to support our core facilities in their development and outreach. Through our R&D teams, we will keep on incorporating novel cutting-edge technologies and workflows. And I am convinced that with our team of data scientists and IT engineers, and with the whole FBI community we will take the right turn in accelerating developments in data processing and data mining.
