Mar 13, 2023

My research focuses on understanding how evolutionary forces shape genetic variation of plant genomes. I have a specific interest for the domestication process. This process has resulted in a loss of diversity due to population bottleneck and selection at target loci. During my PhD, I addressed questions such as: What are the locus involved in the domestication syndrome in millet? What is the influence of the reproductive system on the organization of domestication genes? Since then, I’ve been focusing mainly on maize as a model species. I investigated the influence of recombination and selection in shaping diversity patterns in this species. I have worked both at a small scale to understand the interference between selective sweeps, and at a multilocus scale to model the demographic impact of domestication on diversity and linkage disequilibrium. I used a coalescent model to detect locus under selection in maize. In parallel, I studied the evolution of multigene families encoding enzymes of the starch biosynthesis pathway, the increase of which was a domestication target.

More recently, I have been working on questions related to variation in genome size within and between species in the Zea genus, both from a genomic - Transposable Element (TE) content - and from an ecological perspective (correlation with environmental variables). I also focused on the characterisation on the demographic and adaptive history of European maize, which underwent two independent introductions from the American continent. Admixture between Southern and Northern lineages has triggered adaptation to mid-latitudes in these two continents. Interestingly, we discovered genomic regions with unusual level of residual heterozygosity which we interpreted as the result of selection against inbreeding depression.

Ongoing projects

• Local adaptation of teosintes along altitudinal gradients This work has consisted in collecting natural populations of teosintes, obtaining high-throughput sequencing data at the population level, describing TE content of teosinte genomes, discovering loci targeted by selection, characterizing an adaptative syndrome using common gardens experiments, undertaking association mapping to link genotypic to phenotypic variation.

• Experimental evolution in maize We conducted two divergent selection experiments for flowering date in two homogenous genetic backgrounds (inbreds) over 20 generations. The resulting populations display marked shifts in floral transition. We described a significant and continuous response to selection, that is caused by both selection on residual heterozygosity and new mutations. This response translates at the transcriptomic level with evidence for genetic convergence between maize lines. We are now investigating dynamics of fixation and effects of mutations by combining simulations and association mapping. We are also questioning the impact of such phenological shifts on the root microbiome.

• Reproductive isolation between wild and domesticates Here we are adressing questions such as: What is the extent of reproductive barriers between wild and domesticates? What are the links between reproductive barriers, historical, genomic and phenotypic divergence? What are the molecular determinants of these barriers?

• Maize-Bean intercropping
  Unlike natural and human selection, which has acted for millennia in a multi-specific assemblage context, biotic interactions are minimized in modern agroecosystems. We focus on maize and bean, two crops that are still associated in some traditional European agricultural systems. We seek the potential benefits of this biological partnership which could result from complementarity and/or facilitation processes. We integrate field surveys, agronomic measures, genetic tools to study the evolutionary history and the determinants of maize-bean intercropping. More generally, through the INCREASE project (https://www.pulsesincrease.eu/), we want to promote the description, preservation and use of the genetic resources of food legumes. Learn more about a really cool experiment on beans Citizen Science Experiment.

Community

• Co-animating local initiatives
  Master EvoGEM Seminars: Evolmol and “Evolution en île de France”
  Scientific committee: “GDR AIEM, Interdisciplinary approach of molecular evolution”
• Editorial board member of Genome Biology and Evolution Epigenetics in Ecology and Evolution

Position and Education Full CV

• CNRS researcher, GQE-Le Moulon (2002-present)
• Awarded by the CNRS bronze medal in 2011
• Visiting researcher in the Gaut lab at UC Irvine CA (2009-2011)
• HDR defended 2009 (University Paris-Sud)
• Postdoctoral fellow in the Gaut lab at UC Irvine CA (1999-2002)
• Master and PhD student, Dpt. Evolution and Systematics, University Paris-Sud (1995-1999)

Publications

Publication list