SITE-SPECIFIC CHROMOSOME-DAMAGE AND MYELOID LEUKEMOGENESIS IN THE CBAMOUSE

Deletion and/or rearrangement of chromosome 2 is a very early and poss ibly initiating event for acute myeloid leukaemia in the CBA mouse. He re an outline is given of a series of cytogenetic and molecular studie s which imply that the expression of radiation damage to this chromoso me is highly non-random, being dependent upon the presence of specific telomere-like DNA repeat sequences at certain interstitial chromosoma l locations. The secondary four-stranded DNA structures that may be fo rmed at such telomeric chromosome sites and the potential role of thes e recombinogenic structures as preferential targets for radiation indu ced cytogenetic change are discussed.