1. Program in Computational Biology and Bioinformatics, Yale University, Bass 426, 266 Whitney Avenue, New Haven, CT 06520, USA.
2. Terrence Donnelly Centre for Cellular and Biomolecular Research, Department of Medical Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1.
3. Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1.
4. Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 3E1.
5. Department of Computer Science, University of Toronto, Toronto, Ontario, Canada M5S 3E1.
6. Department of Molecular Biophysics and Biochemistry, Yale University, Bass 432, 266 Whitney Avenue, New Haven, CT 06520, USA.
7. Department of Computer Science, Yale University, Bass 432, 266 Whitney Avenue, New Haven, CT 06520, USA.