1. Laboratory of Integrative Biology of Marine Models, Sorbonne Université, UPMC University of Paris 06, CNRS, UMR 8227, Station Biologique de Roscoff, CS 90074 1 , F-29688, Roscoff , France
2. Department of Algal Development and Evolution, Max Planck Institute for Developmental Biology 2 , 72076 Tübingen , Germany
3. Bezhin Rosko 3 , 29250 Santec , France
4. Electron Microscopy Core Facility, European Molecular Biology Laboratory 5 , 69117 Heidelberg , Germany
5. Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University 4 , Muroran, 051-0013 , Japan