THE DEVELOPMENT OF PAINTING PROBES FOR DUAL-COLOR AND MULTIPLE CHROMOSOME ANALYSIS IN THE MOUSE

The recent development of mouse chromosome painting probes for fluores cence in situ hybridization has extended the use of this common labora tory mammal in cytogenetics. We now report the development of addition al painting probes by degenerate-oligonucleotide-primed PCR on chromos omes from mouse lung fibroblast cultures, each homozygous for a single Robertsonian translocation chromosome. These probes are for Rb(1.2), Rb(1.3), Rb(4.6), and Rb(6.7). Probes were also made for the sex chrom osomes by isolating shoulders from larger peaks (X) or small, clearly resolved peaks (Y) in the flow karyotype. Combinations of probes were used to paint four chromosomes simultaneously in a single color. Multi color painting was achieved with a biotinylated Rb(1.2) probe and a di goxigenin-labeled Rb(2.8) probe. Each of the three different homologou s pairs was uniquely colored by avidin-Texas Red, anti-digoxigenin-FIT C, or both simultaneously. These results extend the usefulness of the mouse as a model for understanding adverse environmental exposures and genetic diseases in humans.