1. Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
2. Department of Zoology, University of Fribourg, Chemi du Musée 10, 1700 Fribourg, Switzerland
3. Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland