Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.|Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.|Computer Laboratory, University of Cambridge, Cambridge, CB3 0FD, UK.|Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. sarinder@um.edu.my.