1. Genomic Analysis Laboratory, The Salk Institute for Biological Studies , La Jolla, CA 92037, United States
2. Department of Genetics, The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine , St Louis, MO 63110, United States
3. McDonnell Genome Institute, Washington University School of Medicine , St Louis, MO 63108, United States
4. Howard Hughes Medical Institute, The Salk Institute for Biological Studies , CA 92037, United States