1. Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
2. College of Life Sciences, Division of Cell and Developmental Biology, University of Dundee, DD1 5EH, Scotland, UK
3. Genome-Scale Biology Research Program, University of Helsinki, FI-00014, Finland
4. Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, SE-171 77, Sweden