Radiation-Induced Delayed Chromosome Aberrations

Abstract

To know the mechanism for delayed formation of chromosome aberrations by radiation, we established the experimental system to analyze delayed chromosome aberrations using a microcell-mediated chromosome transfer. We investigated chromosome alterations by FISH in two different conditions. In one condition, an irradiated human chromosome was transferred into unirradiated recipient mouse cells. In the other condition, an unirradiated human chromosome was transferred into irradiated recipient mouse cells. The results indicated that the irradiated human chromosome was unstable in the unirradiated recipient cells to be rearranged with the recipient mouse chromosomes and that the unirradiated human chromosome also showed an unstable nature in the irradiated recipient cells. Telomere FISH analysis indicated that end-to-end fusions were involved in the formation of delayed chromosome aberrations. These findings suggest that delayed chromosome aberrations can be formed by the interaction between a damaged chromosome and an intact chromosome possibly mediated by telomeric instability. [J Radiat Res 44:374-375 (2003)]