Missions

Diatoms are among the most efficient photosynthetic eukaryotic microalgae. They colonize all aquatic areas and are responsible for approximately 20% of carbon fixation and oxygen production on Earth. They are the result of secondary endosymbiosis between a heterotrophic protist and at least one other photosynthetic eukaryote from the red lineage, itself the result of primary endosymbiosis between a heterotrophic protist and a cyanobacterium. However, despite their ecological importance as primary producers and growing interest in their biotechnological potential, our current understanding of the regulation of photosynthesis in diatoms remains limited, and even the most fundamental questions about plastid biogenesis remain unanswered. Furthermore, genetic approaches to studying chloroplast functions in diatoms are currently limited because the most widely studied model diatoms are obligate phototrophs, for which photosynthesis is essential for survival.
To fill this important gap, our laboratory has chosen the centric diatom Cyclotella cryptica as a new model system for studying the biology of diatom plastids, as it is the only diatom that combines the availability of genomic and genetic resources with the ability to grow heterotrophically in the dark, using glucose as a reduced carbon source, which allows the isolation of photosynthetic mutants. Nuclear gene mutagenesis using the CRISPR/Cas9 strategy, successfully implemented in the laboratory with this alga, has yielded the first photosynthetic mutants in diatoms, paving the way for an in-depth characterization of the regulation of photosynthesis and plastid biogenesis. Building on these recent advances, the objective of this project is to create the first bank of mutants of all plastid genes (approximately 1,500) in C. cryptica for CRISPR-Cas9, and to develop various phenotyping techniques to isolate and characterize mutant genes.

Activities

Building a mutant library for CRISPR CAS9 in the marine diatom Cyclotella cryptica:
- Molecular biology (cloning, plasmid mutagenesis, nucleic acid preparation and analysis, PCR)
- Molecular genetics of diatoms (mutagenesis, transformation, gene expression studies) - DNA sequence analysis

Skills

- Good knowledge of molecular biology
- Proficiency in cloning techniques and genome editing technologies (CRISPR-CAS)
- Proficiency in PCR techniques - Ability to culture cells (plant or otherwise) and work under a laminar flow hood in sterile conditions
- Experience in the physiology of microalgae or photosynthetic bacteria would be an advantage but is not essential

Work Context

The Institute of Physical and Chemical Biology (IBPC), founded in 1930 by the Edmond de Rothschild Foundation, is dedicated to multidisciplinary research in all fields of biology. The candidate will join the “Photobiology and Physiology of Plastids and Microalgae - P3M” laboratory (UMR7141) headed by Dr. Angela Falciatore. The laboratory has around 20 permanent members (researchers, teacher-researchers, engineers, technicians, and administrative staff) and around 15 temporary staff, doctoral students, and post-doctoral researchers. This laboratory, dedicated to the study of light-induced processes (photosynthesis and photoperception) and chloroplast biology, addresses key questions in biology, evolution, and ecology of microalgae, focusing on various model organisms (Chlamydomonas reinhardtii and diatoms, including C. cryptica) and ecologically important phytoplanktonic species, studied using ecophysiological, biophysical, biochemical, genomic, and genetic approaches. The contract is for a renewable period of one year, funded by the CNRS - CNRS BioDivFun project: new models for functional studies.

Constraints and risks

ordinary biological hazards

Additional Information

Applications must be submitted via this interface and must include a CV, a cover letter summarizing the candidate's scientific interests, and the contact details of two scientists who can provide recommendations.