1 Department of Genetics, Stanford University, Stanford, CA 94305; Department of Biology, Stanford University, Stanford, CA 94305; Genome Institute of Singapore, Singapore 138672; yuanzhu@stanford.edu.
2 Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003; and.
3 Department of Genetics, University of Georgia, Athens, GA 30602.
4 Department of Biology, Stanford University, Stanford, CA 94305;