Centre national de la recherche scientifique


CNRS is a government-funded research organization under the administrative authority of the French Ministry of Education and Research. CNRS is the largest basic research organisation in Europe and is involved in national, European, and international projects covering all fields of knowledge.

As part of CNRS in Montpellier, the Centre for Functional and Evolutionary Ecology (CEFE) is one of the most important institutes for research in ecology in France and the research conducted at CEFE strongly contributed to the first position of the University of Montpellier (to which CEFE is associated) in the Shangai ranking for research in ecology in 2018 and 2019. CEFE currently counts 100 researchers in 16 research teams and hosts 70 PhD students, more than 100 master students and around 40 postdocs, including 5 Marie Curie fellows. CEFE's agenda is to understand the dynamics, functioning and evolution of life, from "bacteria to elephant" and "from the genome to the planet". It is constructed around three goals: 1) to understand the living world in order to anticipate what tomorrow will bring; 2) to develop innovations and meet society's expectations; 3) to practice a science that is unifying and diverse in its disciplinary approaches.

The research agenda of the team whose members will be involved in Imptox is directed towards evolutionary biology with research topics ranging from natural and sexual selection to the evolution of life-history traits, the evolution of mating and genetic systems, phylogeography, speciation and hybridization, genetic, mutational, and phenotypic variation and the interface between population genetics and community ecology.

Stéphanie Bedhomme

is a CNRS permanent researcher and head of the Evolutionary Genetic and Ecology Team. Stéphanie Bedhomme got her PhD in evolutionary biology from the University of Montpellier in 2004, while working on the evolutionary ecology of host-parasite interactions. She then moved on to do her postdoc, researching the evolutionary impacts of sexual conflict in Drosophila melanogaster at Queen’s University (Kingston, ON, Canada) after which she continued in the position as a Research and Teaching Assistant at the University of Munster (Germany). She continued her career with a postdoctoral contract at the Institute for Molecular and Cellular Biology of Plants in Valencia (Spain) where she investigated the evolutionary determinants of plant RNA virus host jumps. As a Research Assistant at the Research Institute of Bellvitge (Barcelona, Spain), she started to work on bacterial genomic and the determinants of antibiotic resistance circulation among species. She currently holds an ERC Consolidator grant, researching the role of differences in codon usage bias in shaping the routes of diffusion of antibiotic resistance genes. The main approaches used in this project are experimental evolution coupled with whole genome sequencing, deep-mutant screening by deep sequencing and comparative approaches. For more information on her research please visit:

Martijn Callens

is a post-doctoral researcher at CEFE in Montpellier. He currently works on the ERC project HGTCODONUSE led by Stéphanie Bedhomme as principal investigator. In his research, he applies a combination of comparative genomics and experimental approaches to elucidate the role of codon usage bias in the process of horizontal gene transfer. Before moving to Montpellier, Martijn Callens obtained his PhD in biology at KU Leuven (Belgium). During his PhD at the laboratory for aquatic biology, he investigated environmental and host genetic determinants for the assembly of host-associated bacterial communities on the waterflea Daphnia magna. He further investigated how these host-associated bacterial communities can protect the host against environmental stressors. Martijn Callens has a strong background in microbial community ecology and bacterial evolution. He has considerable experience in using different molecular methods and bioinformatics to address questions in these research domains. For more information on his CV and his publications, please visit .

Méril Massot

is a post-doctoral researcher at CEFE in Montpellier. She currently works on the Imptox project under the guidance of Prof. Andreja Rajkovic and Dr. Stéphanie Bedhomme. Méril obtained her PhD in microbiology from the University of Sorbonne Paris Cité (France) in 2018. During her PhD at the laboratory “Ecology, Evolution and Therapeutic of Virulence and Resistance in Bacteria”, directed by Pr. Denamur, she investigated the maturation of the gut microbiota of veal calves exposed to high levels of antibiotics. She further characterized the dynamics of fecal carriage of extended spectrum β-lactamases-producing E. coli over the fattening period. Before moving to Montpellier, she held a postdoc position at the Shapira lab of the University of California Berkeley, in which she studied host-microbe interactions using the C. elegans model organism. Méril has a strong background in bacteria ecology and molecular forces involved in the spread of virulence and antimicrobial resistance within microbial communities. During her research career, she used a broad range of molecular methods to characterize micro-organisms, and gained solid experience in bioinformatics and statistical analyses to address her research problematics.