Localization of mariner DNA transposons in the human genome by PRINS

Homologous recombination occurring among misaligned repeated sequences is a significant source of the molecular rearrangements resulting in human gene tic disease. Studies of the Charcot-Marie-Tooth disease locus on chromosome 17 have implicated the involvement of an ancient DNA transposon of the mar iner family (Hsmar2) in the initiation of double-strand break events leadin g to homologous recombination. In this study, the genomic locations of 109 HsmaR elements were determined by primed in situ labeling (PRINS) using pri mers designed to match the right and left inverted terminal repeats (ITRs) of the transposon. Although the resolution of the PRINS technique is simila r to 400 chromosomal Giemsa bands, the data presented here provide the firs t large-scale mapping study of these elements, which may be involved in ini tiation of homologous recombination events in the human genome.