1. Center for Plant Molecular Biology (ZMBP), University of Tübingen, 72076 Tübingen, Germany
2. Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York 10065
3. Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 13092 Berlin, Germany
4. Institute for Neurobiology, University of Tübingen, 72076 Tübingen, Germany
5. Department of Computer Science, ETH Zürich, 8006 Zürich, Switzerland