Molecular Physiology Laboratory, Wilkie Building, Teviot Place, University of Edinburgh Medical School, Edinburgh EH8 9AG, UK. j.mullins@ed.ac.uk
The availability of the rat genome sequence, and detailed three-way comparison of the rat, mouse and human genomes, is revealing a great deal about mammalian genome evolution. Together with recent developments in cloning technologies, this heralds an important phase in rat research.