The goal of this Phase I project is to isolate and characterize new chromosome-specific human repetitive DNA elements. The resulting probes will be valuable for cytogenetic cancer diagnostics. Our preliminary results suggest that random amplification of polymorphic DNA (RAPD) is a valuable approach for the discovery of chromosome-specific and polymorphic repetitive DNA elements. Phase I will involve systematic and high- throughput employment of RAPD in a genome-wide search for such elements. The repetitive DNAs will be cloned, then characterized by sequencing, chromosomal localization and sublocalization, heterozygosity determination, evaluation of evolutionary conservation, and determination of average copy number. Additionally, Phase I will include modeling cytogenetic analysis of cancer-relevant chromosomal aberrations using chromosome-specific repetitive DNA probes. Our model system will employ a novel repetitive element mapping to chromosome 20q12, which we discovered in preliminary research using RAPD, as a FISH probe in interphase nuclei representing specific hematological malignancies known to have chromosomal aberrations in this vicinity.
The new human repetitive elements will have a wide range of commercially important uses including probes for cytogenetic cancer diagnosis, genetic mapping, positional cloning, and the identification of individuals. Additionally, highly localized repeats may eventually be valuable reagents in gene therapeutics, since future gene therapy vectors may exploit chromosomal region-specific repeats for targeting DNA into specific sites of the human genome.
