Date : 02/04/2010

Laboratory

UMR de Génétique Végétale INRA UMR 0320 ; CNRS UMR 8120.
Le Moulon 91190 Gif-sur-Yvette
Director : Dominique de Vienne

PhD Supervisor

Olivier Martin
email : This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
phone : +33 169332336

Subjects / Tools-Methodologies

1 : Genomics/Statistics
2 : Systems Biology/Modeling
3 : Bioinformatics/Computational Science

Summary of lab's interests

The research unit is focused on plant genetics. Topics include quantitative genetics, genomics, dynamics of genomes, population genetics, and theory plus practice of selection. Maize, wheat, brassicacees, yeast and arabidopsis are the main models used. The unit combines experimental and theoretical teams, and thus generally stresses modeling and statistical analysis, in particular to get a good hold of the relation between genotypes and phenotypes. Finally, the lab hosts a state of the art proteomics facility while two groups provide support for researchers in their wet lab experiments and bioinformatic analyses.

Summary of project

Meiotic recombination arises through a well orchestrated ìballetî of events: first DNA double strand breaks are induced, then homologs align and pair, allowing for DNA repair which leads to either crossovers (CO) or to non-CO (detectable through associated conversions). Numerous genes are known to be involved in the successive events, but how they work together is still largely open. Note that the formation of crossovers during meiosis is responsible for intra-chromosomal shuffling of alleles from one generation to the next, and is thus a key element of evolution and adaptation in sexual organisms. It is also of major importance in plant selection/breeding programs which explains why INRA has committed to this subject. The goal of this thesis is to provide a detailed understanding of the determinants of crossover formation, going from the early phase of DNA breakage to the final pathways (CO vs non-CO). It is thus necessary to model the different steps, understand their regulation, and find ways to modify their effects. Much of our work is done in collaboration with teams using Arabidopsis as model plant where recent experimental advances have allowed for a fine mapping of the distribution and patterns of double strand breaks, of CO, and of conversions. Some variability in the patterns are known to depend on genomic as well as epigenetic features, and we shall use appropriate data sets to deepen our knowledge. Finally, all aspects, including information on the three dimensional structure of meiotic chromosomes, must be integrated into an accurate in silico model of the meiotic ballet, both to have a synthesis of knowledge but also to have a predictive tool to allow for targeted manipulation of CO patterning. The thesis director is Olivier Martin, and the co-director is Matthieu Falque.