ISOLATION OF THE MOUSE HOMOLOG OF BRCA1 AND GENETIC-MAPPING TO MOUSE CHROMOSOME-11

The BRCA1 gene is in large part responsible for hereditary human breas t and ovarian cancer. Here we report the isolation of the murine Brca1 homologue cDNA clones. In addition, we identified genomic P1 clones t hat contain most, if not all, of the mouse Brca1 locus. DNA sequence a nalysis revealed that the mouse and human coding regions are 75% ident ical at the nucleotide level while the predicted amino acid identity i s only 58%. A DNA sequence variant in the Brca1 locus was identified a nd used to map this gene on a (Mus m. musculus Czech II x C57BL/KsJ)F1 x C57BL/KsJ intersubspecific backcross to distal mouse chromosome 11. The mapping of this gene to a region highly syntenic with human chrom osome 17, coupled with Southern and Northern analyses, confirms that w e isolated the murine Brca1 homologue rather than a related RING finge r gene. The isolation of the mouse Brca1 homologue will facilitate the creation of mouse models for germline BRCA1 defects. (C) 1995 Academi c Press, Inc.