Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland, SIB Swiss Institute of Bioinformatics, Basel, Switzerland.|Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.|Biozentrum, University of Basel, Basel, Switzerland.|Biozentrum, University of Basel, Basel, Switzerland.|Biozentrum, University of Basel, Basel, Switzerland.|Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.|Algorithmic Bioinformatics, Bonn-Aachen International Center for IT, University of Bonn, Bonn, Germany.|Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland, SIB Swiss Institute of Bioinformatics, Basel, Switzerland.