Date : 01/04/2011

Laboratory
IBENS (from fall 2011 - presently at Institut Jacques Monod)`
UMR8197 / U124
ENS/CNRS/Inserm
46 rue d'Ulm
75005 Paris
Website : http://www.ijm.fr/en/ijm/research/research-groups/nematode/
Lab director : Marie-Anne Félix

PhD Supervisor
Marie-Anne Félix
email : This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
phone : +33-1-57-27-80-67

Subjects
1.: co-evolution
2.: host-pathogen interactions
3.: small RNAs

Tools and methodologies
1.: experimental evolution
2.: molecular biology

Summary of lab's interests

The main interest of the lab concerns the integration of mechanistic and evolutionary questions. We combine a wide range of approaches - experimental and population genetics, evolution of development, phylogeny, modelisation, system biology and ecology, microevolution and macroevolution - in what may be called "evolutionary systems biology". As a model system, we study the evolution and evolvability of the cellular and molecular signaling network underlying nematode vulva development. Our work was a major contribution towards making C. elegans a model for evolutionary biology, in particular through natural population studies. We isolated several natural pathogens of C. elegans, which will be relevant to study defense systems and their rapid evolution.

Summary of project

Experimental evolution of Caenorhabditis elegans and a natural infectious virus. Reciprocal interactions between host and pathogen potentially drive fast evolution of both partners. Our laboratory recently discovered infections of the nematode C. elegans by an RNA virus, the Orsay virus (Félix, Ashe, Piffaretti et al. 2011). This small, horizontally transmitted, RNA(+) virus is related to arthropod and fish nodaviruses. Infection elicits the formation of viral small RNAs that play a role in host defense. This infection system involving a laboratory top model in genetics and a pathogen is the simplest and fastest available and can have a wide impact in virology and evolutionary studies. The present project focuses on an experimental evolution approach using this system. Experimental evolution is a method of choice to test specific hypotheses in a controlled manner. The project would be to use experimental evolution of C. elegans and the Orsay virus and specifically test whether evolutionary dynamics differs when host and pathogen evolve separately or co-evolve. A particular feature of the proposed system is that the small interfering RNA repertoire may be epigenetically transmitted in C. elegans, allowing to test for epigenetic "evolution" consequences on co-evolutionary dynamics, a very novel aspect. Because of the fast replication and high mutation rate of RNA viruses, the Orsay virus is likely to evolve rapidly. On the host side, C. elegans reproduces and evolves fast enough for fruitful experimental evolution, relying on initial genetic variation or even de novo mutation. C. elegans mode of reproduction allows to test for male maintenance and role of outcrossing in adaptation. In this case where the host mounts an immune response through small RNAs matching the viral genome, which may be passed on trans-generationally, a particularly exciting avenue is to test in a controlled manner the influence of the epigenetic immune state of the host on virus evolution and diversification. Bibliography MA Félix, A Ashe, J Piffaretti et al., PLoS Biol 9, e1000586 (2011).

Interdisciplinarity of the project

Evolution and ecology are not central subjects in our regular graduate school (B3MI now and CdV in the future).