1. Embrapa- Genetic Resources and Biotechnology; Brasília DF 70770-917 Brazil
2. School of Agriculture and Veterinary Medicine; University of Brasilia; Brasília DF 70910-900 Brazil
3. Center for Applied Genomics; The Children's Hospital of Philadelphia; Philadelphia PA 19104 USA
4. Department of Computer Science; New Jersey Institute of Technology; Newark NJ 07102 USA
5. Division of Epidemiology and Biostatistics; University of Arizona; Tucson AZ 85721 USA