DNA Replication Defects in the Telomere Induce Chromosome Instability in a Single Cell Cycle
AuthorLangston, Rachel Elizabeth
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractErrors in DNA replication can cause chromosome instability and gross chromosomal rearrangements (GCRs). For my thesis work I investigate how chromosome instability can originate in the telomere. Here I report how defects in Cdc13, a telomere specific protein, lead to chromosome instability and GCRs in Saccharomyces cerevisiae. Using a temperature sensitive mutant of Cdc13, I find that cdc13-induced instability can be induced in a single cell cycle and synergizes with replication stress (dNTP depletion via hydroxyurea). Additionally, I find that Cdc13 has to be functional during the cell’s S phase to suppress chromosome instability. Further genetic analysis suggests that that cdc13-induced chromosome instability depends on the generation of single stranded (ss)DNA, but not on the activity of canonical double strand break (DSB) repair pathways such as homologous recombination or non-homologous end joining. Finally, I demonstrate that telomeric unstable chromosomes can later progress and trigger rearrangements at centromeric loci. This system, using the conditional nature of the cdc13 mutation, promises a more complex analysis of the ontogeny of chromosome instability: in this case from errors semi-conservative DNA replication through the telomere to the formation and resolution of unstable chromosomes.
Degree ProgramGraduate College
Molecular & Cellular Biology