1. School of Engineering and Applied Sciences, Department of Molecular and Cellular Biology, FAS Center for Systems Biology, Harvard University, Cambridge, Massachusetts 02138
2. Department of Biology, University of Florida, Gainesville, Florida 32611
3. Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
4. University of Florida Genetics Institute, University of Florida, Gainesville, Florida 32611