To contribute to the physical gene map of mouse chromosome 11 (MMU11) and to extend the mapping resources available for this chromosome, we have produced mouse x rat somatic cell hybrids containing only bands B5 to E of MMU11. Characterization of the hybrids by polymerase chain reaction (PCR) amplification and Southern blot analyses of MMU11 markers revealed two hybrids, T16Ad14B and T16Ad19A, that had selectively retained the 3(11) translocation product containing distal MMU11 (bands B5-E). Cytogenetic analysis of the hybrid T16Ad14B by fluorescence in situ hybridization (FISH) and conventional G-banding confirmed the presence of the 3(11) translocation chromosome. Mapping of markers in both the T16Ad14B and T16Ad19A hybrids localized the T16Ad translocation breakpoint between the proximal markers Atplb2 and Acrb and the more distal markers Scya2 and Mpo. Loci for D11Mit5, Rpo2-1, Trp53, Glut4, Acrb, and Atplb2 could all be localized proximal to the T16Ad breakpoint in band B5, between bands B1 and B5 on MMU11.