EXTENSION OF CONSERVED REGIONS IN THE RAT AND MOUSE GENOMES BY CHROMOSOMAL ASSIGNMENTS OF 29 RAT GENES

We recently constructed a comparative genetic map of the rat, mouse an d human genomes based on information obtained from several databases. In this study, we performed chromosomal assignments of 29 rat genes wi th somatic cell hybrid clones, in order to clarify and extend the cons erved regions in the rat and mouse genomes. As a result, the conserved regions were extended by 89 cM. Together with our previous report, th e length of the conserved regions in the rat and mouse spans 847 cM on the mouse linkage map, indicating that 53% of the mouse genome is cov ered by homologous regions in the rat. In addition, four conserved reg ions were newly revealed. The method described in this study appears t o be simple and efficient for constructing a whole genome comparative map of the rat and mouse.