Alternative Lengthening of Telomeres Is Characterized by High Rates of Telomeric Exchange

Abstract Telomere maintenance activity is a hallmark of cancer. In some telomerase-negative tumors, telomeres become lengthened by alternative lengthening of telomeres (ALT), a recombination-mediated DNA replication process in which telomeres use other telomeric DNA as a copy template. Using chromosome orientation fluorescence in situ hybridization, we found that postreplicative exchange events involving a telomere and another TTAGGG-repeat tract occur at remarkably high frequencies in ALT cells (range 28–280/100 metaphases) and rarely or never in non-ALT cells, including cell lines with very long telomeres. Like the ALT phenotype itself, the telomeric exchanges were not suppressed when telomerase was activated in ALT cells. These exchanges are telomere specific because there was no correlation with sister chromatid exchange rates at interstitial locations, and they were not observed in non-ALT Bloom syndrome cells with very high sister chromatid exchange rates

Peyrepertuse. Forteresse royale [Préface de Marcel Durliat ]

Bayrou Lucien, Alessandri Patrice, Barrere Michel, Bonnet Patrick, Bouvier Christian, Cazes Jean-Paul, Delva Bernadette, Doutres Bernard, Fonquernie Laurent, Fontan Patrick, Franquet Denise, Martzulff Michel, Mayans Alex, Maso David, Merckx Jean-Luc, Séguy Isabelle, Travé Joseph, Vargas Jean-Manuel. Peyrepertuse. Forteresse royale [Préface de Marcel Durliat ]. In: Archéologie du Midi médiéval. Supplément n°3, 2000. Peyrepertuse. Forteresse royale. pp. 3-288