1. Institut de Génétique et Microbiologie, Université Paris‐Sud (XI), UMR 8621 CNRS 91450 Orsay, France
2. Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain
3. Dept. of Microbiology, Imperial College London, South Kensington Campus, Flowers Building, Armstrong Road, London SW7 2AZ, UK
4. Institute of Biology, National Center for Scientific Research, Demokritos (NCSRD), Aghia Paraskevi, 15310 Athens, Greece
5. Dept. of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, England
6. Faculty of Biology, University of Athens, Panepistemioupolis, 15784 Athens, Greece