PhD in Biology (M/F) : Adapative mechanisms in fluctuating environments

Job Description

Thesis Subject

Biological systems are the product of evolution in a dynamically changing world. Therefore, determining how environmental dynamics influences the evolution of different adaptive strategies is essential to explain the complexity of living systems. In theory, biological systems can adapt to fluctuating selection pressure either via the evolution of stochastic phenotypic variation ("noise") or through the evolution of regulated phenotypic variation ("plasticity").

The first objective of this project is to determine how the evolution of these two adaptive strategies depends on 1) the frequency at which they are generated by random mutations and 2) the selective advantage provided by each strategy under diverse regimes of environmental fluctuation. To address this fundamental question, a powerful experimental system centered around the baker's yeast Saccharomyces cerevisiae will be implemented. Innovative genetic tools will be used to independently manipulate the evolvability of the system and the selection regime, allowing to measure how these two parameters contribute to the evolution of expression noise and expression plasticity of a yeast gene. A transcriptome-scale approach based on RNA sequencing of micro-colonies, currently under development in the team, may also be considered.

The second objective is to explore the diversity of genetic mechanisms involved in the evolution of gene expression in fluctuating environments. To achieve this, approximately sixty adaptive mutations affecting expression noise or expression plasticity of one or more genes will be identified through a high-throughput genetic mapping approach. We will then investigate whether these mutations share certain properties, such as their position in regulatory networks or their location in coding and non-coding regions of the genome. These analyses will help predict which genetic, molecular, and cellular mechanisms contribute to adaptation under fluctuating environments.

This work will provide an opportunity for the PhD student to develop both experimental biology skills (molecular biology, flow cytometry, yeast genetics) and quantitative and statistical data analysis skills.

Your Work Environment

You will be supervised by Fabien Duveau at the Laboratory of Biology and Modeling of the Cell (LBMC) of the ENS de Lyon. You will join the GECO team, "Genetic Complexity of Living Systems," which is co-directed by F. Duveau and G. Yvert (https://www.ens-lyon.fr/LBMC/gisv/index.php/en/). The LBMC is a cutting-edge research institution dedicated to studying the fundamental mechanisms of cellular life. The laboratory combines experimental approaches in molecular, cellular, and genetic biology with mathematical and computational modeling methods to understand complex processes that regulate cell function.
In your work environment, you will benefit from interdisciplinary expertise, including through the LBMC's biocomputational hub, as well as access to flow cytometry and imaging platforms of the SFR Biosciences and the sequencing facilities of the IGFL. The GECO team currently consists of two permanent researchers, one permanent study engineer, three research engineers (with varying levels of specialization in bioinformatics or molecular biology), one PhD student, and one final-year engineering intern.
You will also will also benefit from the LBMC's active student life, driven by the student committee, which organizes seminars, various events, and can provide support at different stages of a PhD.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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