A gene map of the rat derived from linkage analysis and related regions inthe mouse and human genomes

We report the localization by linkage analysis in the rat genome of 148 new markers derived from 128 distinct known gene sequences. ESTs, and anonymou s sequences selected in GenBank database on the basis of the presence of a repeated element. The composite linkage map of the rat contributed by our g roup integrates mapping information on a total of 370 different known genes , ESTs, and anonymous mouse or human sequences, and provides a valuable too l for comparative genome analysis. 206 and 254 homologous loci were identif ied in the mouse and human genomes respectively. Our linkage map, which com bines both anonymous markers and gene markers, should facilitate the advanc ement of genetic studies fur a wide variety of rat models characterized for complete phenotypes. The comparative genome mapping should define genetic regions in human likely to be homologous to susceptibility loci identified in rat and provide useful information for the identification of new potenti al candidates for genetic disorders.