Description du sujet de thèse

Plants use sunlight for photosynthesis and have to cope with the harmful effects of ultraviolet (UV). UV induces DNA lesions (photolesions) which modify the conformation of the DNA and interfere with DNA replication and transcription. Photolesions are repaired by 2 main pathways: Direct Repair (DR) and Nucleotide Excision Repair (NER). DR is a light-dependent repair mechanism involving photolyases that reverse DNA damage. NER is independent of light and involves the excision of photolesions and the synthesis of a new strand of DNA free from any damage. The research team demonstrated that the orientation of repair by one or the other pathway depends on the level of chromatin compaction and therefore on the epigenetic context of the UV-damaged regions. The objective of the project is to characterize the loading dynamics on the chromatin of different factors involved in DR and/or in NER depending on the epigenetic context.

The project will focus on two axes:

The first axis will aim to characterize/ identify genetic and epigenetic factors that influence the dynamics of photodamage recognition factors. For this the association/dissociation with chromatin will be followed in different genetic backgrounds presenting alterations of the epigenome.

The second axis will aim to characterize genomic regions (i) where photodamage recognition factors are present (ii) enriched in photolesions. The combination of these different approaches will allow characterizing the genetic and epigenetic determinants involved in the formation and recognition of UV-induced DNA damage.

This project offers knowledge and experience in cell biology, molecular biology, genetics, and bioinformatics. The candidate (M/F) will learn techniques in chromatin biochemistry, microscopy, and functional genomics. The candidate (M/F) will also be trained in writing and communication skills, as well as in presenting results to different audiences.

Contexte de travail

The position is located at IBMP in Strasbourg (France) and is available for 36 months, starting in October 2025. The Institute of Molecular Biology of Plants (IBMP; http://www.ibmp.cnrs.fr) is the largest CNRS research institute in plant sciences in France. It hosts 20 research teams and is recognized for its expertise in genomics, genetics, metabolism, biochemistry, cell biology and molecular physiology of plants.

The candidate (M/F) will be enrolled in the Doctoral School of Life and Health Sciences at the University of Strasbourg (http://ed.vie-sante.unistra.fr/) which offers numerous technical and cross-disciplinary training courses (108 hours of mandatory training). Within the laboratory, the candidate (M/F) will be supervised by a permanent researcher and a monitoring committee will support them throughout their thesis project.

The candidate (M/F) will join the ANR UVChrom project (UV stress and development: genome-epigenome dynamics in relation to DNA damage capacity and repair mechanisms) involving 3 partners.

Contraintes et risques

The candidate (M/F) must hold a master's degree in molecular and/or cellular biology, be able to communicate in English both written and oral (level B2 or higher), and be interested in functional genomics. The candidate (M/F) must have experience in molecular biology, biochemistry and microscopy. Previous experience in the field of bioinformatics is an asset.