Abstract
To construct rapidly both genetic and physical maps in the laboratory rat (Rattus norvegicus), we examined the availability of cosmid clones containing rat genomic large DNA inserts as resources of informative markers. Ninety of the 95 cosmid clones examined were specifically hybridized with an (AC)15 oligonucleotide probe, which suggested that they contain (AC/TG)n repeats which are highly polymorphic. Primer sets were prepared to amplify the microsatellite regions by polymerase chain reaction (PCR), and linkage analysis based on the size polymorphisms was successfully carried out. Each DNA insert could be assigned to a particular chromosome by rat×mouse somatic cell hybrid analysis, and localized within a discrete chromosomal subregion by fluorescent in situ hybridization (FISH) using the cosmid probes. This approach should be an excellent strategy for rapid construction of an ideal genetic marker map. In addition, a genomic library consisting of the mapped clones should become a useful tool for positional cloning of causative genes in rat models of human genetic disease.
