1. Department of Computer Science, University of Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa PI, Italy
2. CeBiB—Center for Biotechnology and Bioengineering, Santiago, Chile
3. Escuela de Informática y Telecomunicaciones, Diego Portales University, Ejército 441, Santiago, Chile
4. Department of Computer Science, University of Chile, Beauchef 851, Santiago, Chile
5. Department of Computer Science, University of Helsinki, Helsinki, Finland
6. Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK