CONICET | Buscador de Institutos y Recursos Humanos

Telomeres are specialized nucleoproteic complexes localized at the physical ends of linear eukaryotic chromosomes that maintain their stability and integrity. In vertebrate chromosomes, the DNA component of telomeres is constituted by (TTAGGG)n repeats, which can be localized at the terminal regions of chromosomes (true telomeres) or at intrachromosomal sites (interstitial telomeric sequences or ITS, located at the centromeric region or between the centromere and the telomere). In the past two decades, the use of molecular cytogenetics techniques allowed to distinguish a new spectrum of spontaneous and clastogen-induced chromosomal aberrations, the ones involving telomeres and ITS. Some aberrations involve the chromosome ends and, indirectly, the telomeric repeats located at the terminal regions of chromosomes (true telomeres). A second type of aberrations directly involves the telomeric sequences located at the chromosome ends. Finally, there is a third class of aberrations that specifically involves the ITS. The aim of this review is to provide a detailed description of these aberrations, and summarize data so far available regarding their induction by physical and chemical mutagens.