1. Howard Hughes Medical Institute and the Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
2. Biophysics Graduate Group, University of California, Berkeley, CA, USA.
3. Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, CARMABI, Piscaderabaai z/n Willemstad, Curaçao.
4. Electron Microscopy Laboratory, University of California, Berkeley, CA, USA.