Bioinformatics Group, Institute of Cell and Molecular Science, The Genome Centre, Queen Marys School of Medicine and Dentistry, Charterhouse Square, London, EC1M 6BQ, UK. j.a.casbon@qmul.ac.uk|Bioinformatics Group, Institute of Cell and Molecular Science, The Genome Centre, Queen Marys School of Medicine and Dentistry, Charterhouse Square, London, EC1M 6BQ, UK. j.a.casbon@qmul.ac.uk