Regional localization of 64 cosmid contigs, including 18 genes and 14 markers, to intervals on human chromosome 9q34.

A fluorescence in situ hybridization map of distal human chromosome 9q has been produced by mapping cosmid clones to metaphase chromosomes with balanced reciprocal translocations. This is a very accurate method of mapping, as clones are localized by their position with respect to the breakpoint in addition to cytogenetic banding. By using three lymphoblastoid cell lines with translocation breakpoints within 9q34, we have localized 18 genes and 14 DNA markers to one of four intervals on the chromosome. Cosmid contigs exist around 16 of these genes and 12 of these markers. A further 43 contigs have also been mapped, but they are as yet anonymous.