1. Genome Biology Unit, European Molecular Biology Laboratory (EMBL) , Heidelberg, Germany
2. Department of Biosystems Science and Engineering , ETH Zurich, Basel, Switzerland
3. Center for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology , Barcelona, Spain
4. Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) , Heidelberg, Germany
5. Department of Computational Biology, University of Lausanne , Lausanne, Switzerland
6. Department of Genetics, Stanford University School of Medicine , Stanford, CA, USA
7. Stanford Genome Technology Center , Palo Alto, CA, USA