REGIONAL LOCALIZATION OF TRINUCLEOTIDE AND TETRANUCLEOTIDE REPEAT SEQUENCE-CONTAINING COSMIDS ON CHROMOSOME-13

A human chromosome 13-specific cosmid library has been screened with o ligonucleotides containing tri- and tetranucleotide repeats with motif s: GACA, GACT, CAC, TCC. 20 cosmid clones were identified and their ph ysical location on chromosome 13 was determined using fluorescence in situ hybridisation. Over 80% of the cosmids were detected using tetran ucleotide repeats of which 50% were GACT, but these were distributed a long the length of the chromosome. Clones from the 13q12-->q14 and 13q 32-->q34 regions were apparently overrepresented and 10% of cosmids we re localised to the short arm of the chromosome. These simple tandem r epeats will be an important addition to the genetic mapping strategy f or human chromosome 13.