Host-parasite interactions are widespread in unicellular marine plankton. Our previous work has shown that a eukaryotic parasite (Syndiniale) is able to infect microalgae (host, dinoflagellate), and more specifically to enter its nucleus to digest the nutrient-rich chromosomes (more info here in this preprint: https://www.biorxiv.org/content/10.1101/2021.11.04.467241v1). This trophic strategy allows a significant intracellular development of the parasite’s organelles and to form a multitude of spores (dinospores) at the end of the infection. The main objective of the postdoctoral project will be to better understand the trophic strategies of the parasite during its intracellular development in the host by using subcellular imaging techniques (nanoSIMS coupled to isotopic labeling and 3D electron microscopy) and metabolomics (lipidomes). More specifically, the candidate will study the central carbon metabolism of the host and the parasite to highlight the carbon homeostasis and metabolic exchanges between the two partners during infection. In addition, to characterize the metabolism and infection mechanisms of the free-living form of the parasite (dinospores), the second objective of the project will be to reveal the 3D ultrastructure of the dinospores released after infection with 3D electron microscopy approaches (FIB-SEM and cryo-tomography).
Please Apply HERE: https://bit.ly/3wVD6PB
Project: The candidate will be part of the Photosymbiosis team (photosymbiosis.com) of the LPCV -laboratory of Cell and Plant Physiology- (UMR 5168 – CNRS -CEA – Univ. Grenoble Alpes – INRAE) within the IRIG institute of the CEA in Grenoble. He or she will also work in close collaboration with the Lipid Team of LPCV (Juliette Jouhet). The research projects of the Photosymbiosis team aim at better understanding the functioning of interactions between single-celled eukaryotes, including photosynthetic partners (photosymbiosis, parasitism) by combining subcellular microscopy approaches (nanoSIMS, Synchrotron X-Ray fluorescence, 3D electron microscopy). Locally, the project will be in close collaboration with the IRIG institute in Grenoble: INAC platform (IRIG) and the Institute of Structural Biology (IBS). This postdoctoral project is part of the EPHEMER project led by the Station Biologique de Roscoff (Laure Guillou, CNRS) and funded by the Agence Nationale de la Recherche. The candidate will interact regularly during meetings with the project partners: Station Biologique de Roscoff (CNRS-Sorbonne Univ), IFREMER, and Jena Friedrich-Schiller University.
– Cultivation of the microalgae (host) – parasite system in the laboratory
– Photo-physiological analyses (photosynthesis, carbon fixation)
– Incubation with stable isotopes coupled to nanoSIMS
– 3D electron microscopy (FIB-SEM and cryo-electron tomography)
– Image analysis (segmentation, 3D reconstruction)
– Communication through international meetings and workshops.
Competences and qualifications:
– PhD in cell biology, physiology, host-pathogen interactions, ecology, photosynthesis
– Knowledge and interest in cellular interactions: mutualistic symbioses or parasitism
– Expertise in microalgae culture and physiology and epifluorescence microscopy will be appreciated
– Knowledge and expertise in sample preparation for 3D electron microscopy (FIB-SEM, cryo-TEM), and image analysis for 3D reconstruction.
– Ability to work independently in an interdisciplinary and international environment (fluent English), and to interact in a young and dynamic research group.