School of Electrical Engineering and Computer Science, Ohio University, Athens, Ohio, United States of America.|Bioinformatics and Research Computing, Whitehead Institute, Cambridge, Massachusetts, United States of America.|Department of Biological Sciences and School of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America.|European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom.|School of Informatics and Computing, Indiana University, Bloomington, Indiana, United States of America.|School of Computer Science and Engineering, The University of New South Wales, Sydney, New South Wales, Australia.|The Genome Analysis Centre, Norwich Research Park, Norwich, United Kingdom.