Dicentric breakage at telomere fusions
- Commissariat à l’Énergie Atomique, Direction des Sciences du Vivant/Institut de Radiobiologie Cellulaire et Moléculaire/Service Instabilité Génétique Réparation et Recombinaison/Laboratoire Télmère et Réparation du Chromosome, Fontenay-aux-roses 92260, France; and Centre National de la Recherche Scientifique, UMR217, Fontenay-aux-roses 92260, France
Abstract
Nonhomologous end-joining (NHEJ) inhibition at telomeres ensures that native chromosome ends do not fuse together. But the occurrence and consequences of rare telomere fusions are not well understood. It is notably unclear whether a telomere fusion could be processed to restore telomere ends. Here we address the behavior of individual dicentrics formed by telomere fusion in the yeast Saccharomyces cerevisiae. Our approach was to first stabilize and amplify fusions between two chromosomes by temporarily inactivating one centromere. Next we analyzed dicentric breakage following centromere reactivation. Unexpectedly, dicentrics often break at the telomere fusions during progression through mitosis, a process that restores the parental chromosomes. This unforeseen result suggests a rescue pathway able to process telomere fusions and to back up NHEJ inhibition at telomeres.
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Footnotes
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↵1 Corresponding author.
E-MAIL stephane.marcand{at}cea.fr; FAX 33-1-46-54-91-80.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.571510.
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- Received December 8, 2009.
- Accepted February 22, 2010.
- Copyright © 2010 by Cold Spring Harbor Laboratory Press