1 Department of Energy Joint Genome Institute, Genome Biology Program, 2800 Mitchell Drive, Walnut Creek, USA.
2 Department of Energy Joint Genome Institute, Genome Biology Program, 2800 Mitchell Drive, Walnut Creek, USA ; Present Address: Computational Biology Group, Celgene Corporation, Summit, USA.
3 Biosciences Computing, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, USA.