YEAST ARTIFICIAL CHROMOSOME MAPPING OF THE CYSTINOSIS LOCUS ON CHROMOSOME 17P BY FLUORESCENCE IN-SITU HYBRIDIZATION

The gene locus for cystinosis has been mapped between markers D17S1583 and D17S1584 on the short arm of chromosome 17. Using markers encompa ssing the cystinosis region, we assigned different yeast artificial ch romosome (YAC) clones previously identified by sequence tagged site (S TS) screening to 17p13.3. Three of the clones hybridized to the target 17p gene region; one of these was chimeric, hybridizing both to chrom osomes 3p and 5q; two of the YACs did not contain sequences of 17p13.3 , Our physical mapping has identified candidate YACs as a first step t owards a positional cloning approach.