Missions

This postdoctoral contract is funded by the ANR grant ProtecTE (Deciphering the Protective role of Transposable Element in antiviral response)

Project description
Transposable Elements (TEs) are genomic parasites. They are pieces of DNA that are able to move and multiply along the chromosomes, through various mechanisms, some of which being tightly similar to certain viral cycles. This behavior is a direct threat to the integrity of the genome, and mechanisms have evolved which control TE activity. RNA interference (RNAi) is one of those, and relies on small RNA molecules that target TEs by sequence complementarity. Two main RNAi pathways are involved in TE control, that differ in their molecular actors and RNA precursors: the piRNA pathway, mostly described in gonads, and the siRNA pathway, also active in the soma. In many organisms, RNAi is also involved in antiviral immunity, through the siRNA pathway. For almost a decade now, we have been investigating the potential connections between TE control and antiviral immunity, and have shown that they were not independent (Roy et al., 2020; 2021; Garambois et al., 2024; Mayeux et al. 2024). Using Drosophila C Virus (DCV), a virus that encodes a viral suppressor of RNAi, our latest results revealed that Drosophila strains displaying a high load of TE sequences in their transcriptomes display low DCV titers upon experimental infections (Mayeux et al., 2024). Hence, the objective of the present project is to determine the molecular mechanisms and the evolutionary impacts of this potential protective role of TEs against the replication of DCV.

Activities

the selected person will perform experimental infections of flies and subsequent molecular biology experiments in order to investigate the underlying mechanisms. She/he will also measure fly fitness (fecundity and survival) under different infectious conditions. Finally, she/he will analyze RNAseq data from a collection of samples from the field in order to investigate the natural viral load and TE activity. .

Skills

The selected person should be autonomous in molecular biology experiments, with a background and interest in genomics and/or evolution of interactions. A previous experience in insect infections would be an advantage. We are looking for a meticulous, well-organized and creative person, with a clear sense of collective commitment. Meetings in the group are held in English. French may help in social interactions but is not mandatory.

Work Context

The person recruited will work in the Biometrics and Evolutionary Biology Laboratory (LBBE) on the Lyon-Tech La Doua university campus in Villeurbanne (near Lyon).The project will be supervised by Marie Fablet (Associate Professor, LBBE UMR CNRS 5558, Université Lyon 1), who leads the TE axis (within the “Genetics and Evolution of Interactions” group), gathering Cristina Vieira and Matthieu Boulesteix, two professors of University Lyon 1, and PhD students and post-docs. They have a long-term expertise in TE dynamics and evolution, especially in Drosophila species. The group combines know-hows in molecular biology, population genetics and bio-informatics specifically dedicated to TE biology. In addition, this project is performed in collaboration with Rita Rebollo (CR INRAE, BF2I), Natacha Kremer (CR CNRS, LBBE), and Séverine Chambeyron (DR CNRS, IGH, Montpellier), for their acknowledged expertise in TEs, insect immunity, and Drosophila genetics and small RNA biology, respectively. LBBE displays all necessary facilities for fly rearing and molecular biology experiments, in association with DTAMB (Development of Techniques and Molecular Analysis for Biodiversity, University Lyon 1 http://www.dtamb.univ-lyon1.fr), and powerful computing resources, in association with PRABI (Pôle Rhone-Alpin de Bio-Informatique, http://www.prabi.fr).
Lyon is France's 3rd largest city and is very dynamic with 180,000 students. It has a rich history that traces back to the Romans and it is included on the list of UNESCO world heritage sites (https://whc.unesco.org/en/list/872/). Lyon is surrounded by natural Parks (Vercors, Chartreuse, Haut-Jura, Livradois-Forez, Ardèche...) and is two hours away from the Alps. Geneva is accessible by train or car in less than two hours, Paris in 2 hours by train as are Marseille and the Mediterranean Sea.

Additional Information

Our little extras :
- A stimulating working environment in contact with research staff
- Professional support with in-house laboratory training
- The possibility of teleworking
- A company restaurant where you can have lunch at a reasonable price.
- Partial reimbursement of travel expenses (75%)
+ sustainable mobility package of up to €300/year
- A site accessible by public transport (Tram T1 + T4 + bus)
- 44 days' holiday / RTT per year
- Financial contribution towards the cost of health insurance