I am Marie Walde, a biophysicist studying small eukaryotes in the marine plankton with advanced 3D light microscopy and image analysis at the marine reserach station in Roscoff/Bretagne (France).
My research is funded by the German Research Council (Deutsche Forschungsgemeinschaft)
I work on deciphering the morphologies and cellular interactions of unicellular marine microbes,
in particular understudied small protists.
Towards this goal, I develop and use tailored bioimaging and image processing methods,
including automated and super-resolution microscopy to address their challenging diversity
and connect information across large scale ranges.
EU project BlueRemediomics: Research on marine microbial ressources
Independent Research Fellowship by the German Reserach Foundation (DFG)
Project SymbioScope: Assessing the ecological diversity and dynamics of symbiotic interactions in a key phytoplankton by automated high-content 3D microscopy
Hosted by Fabien Burki, Department of Organismal Biology
Automated microscopy to elucidate unknown eukaryotic diversity
Stratégie d'attractivité durable (SAD) International Postdoctoral Fellowship by the Région Bretagne:
Competitive fellowship aimed at international researchers who bring new methods and expertise to research establishments based in Bretagne
Supervised by Nathalie Simon & Colomban de Vargas,
Ecology of Marine Plankton Group
Project IMASTAN: Automated imaging of phytoplankton in the SOMLIT-Astan time series
Systems Biology Imaging Platform, headed by Andrew Woehler
Max Delbrück Center (MDC) for Molecular Medicine in the Helmholtz Association
Plasticity of hippocampal neurons; superresolution fluorescence neuroimaging
Host of monthly MicroscopyClub together with Nikita Vladimirov
Leibniz Institute of Photonic Technologies & Institute of Physical Chemistry
Supervised by Rainer Heintzmann, Nanobiophotonics Research Group
Research Project: Development of a holoscopic imaging system and applied high-resolution fluorescence microscopy
Randall Centre for Cell & Molecular Biophysics
Research Project: High-resolution fluorescence microscopy with photoswitchable proteins
Research Project: Resolution improvement with structured illumination fluorescence microscopy applied to biological research
Fluorescence microscopy, automated microscopy, super-resolution microscopy, image processing & quantitative analysis, plankton sampling and filtration, plankton culturing, optical design & calibration, instrument control, fluorescent labelling & immunocytochemistry, in-situ hybridization, interferometry, 3D modelling and printing
Background & Objective: Typical dimensions of synaptic structures are below the diffraction limit of light. Synaptic cleft sizes are 20-40 nm, and the diameter of synaptic vesicles is ~50-200 nm. The aim of this project was to study the spatial distribution of proteins at the presynaptic terminal and map their localisation against pre- and post-synaptic markers (Bassoon, PSD95) on hundreds of synapses in parallel. However, multicolour imaging is challenging on the nanoscale, as it requires precise image registration, and chromatic aberrations or drift can easily disturb these measurements.
Results: I assembled a custom superresolution microscope based on nanoscale localisation microscopy for the simultaneous acquisition of up to 4 different fluorophores with a single excitation laser, objective, camera, and a large field of view. The spectral fingerprint of each emission event serves to classify fluorophore. This was a new method at the MDC. I autonomously established and optimised the entire pipeline, from sample preparation, optical design, laser safety, instrument control, and image acquisition to data handling and image analysis.
Left: Monitoring of hundreds of individual diatoms with automated high-throughput microscopy.
Bottom right: The size and shape of chloroplasts and nuclei was analysed with 3D morphometry. Chloroplast deformation after viral infection coincides with the drop in photosynthetic efficiency of the bulk culture.
Top right: Two main cell fates were observed, lysis or auxospore formation.
This section is still under construction. More content is coming soon.
Ecology of Marine Plankton
Station Biologique de Roscoff
CNRS & Sorbonne Université
Place Georges Tessier, 29680 Roscoff, FRANCE