1. Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco, and California Institute for Quantitative Biosciences, San Francisco, CA 94158, USA.
2. Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA.
3. Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
4. School of Engineering and Computer Science, Hebrew University, Jerusalem 91904, Israel.
5. Alexander Silberman Institute of Life Sciences, Hebrew University, Jerusalem 91904, Israel.