Coupling Transcriptional State to Large-Scale Repeat Expansions in Yeast

• DOI: 10.1016/j.celrep.2014.10.048
• Publication Date: 2014-11-21T01:02:04Z
• Authors: Kartik A. Shah; Ryan J. McGinty; Vera I. Egorova; Sergei M. Mirkin
• Keywords: Transcription

Expansions of simple DNA repeats cause numerous hereditary disorders in humans. Replication, repair, and transcription are implicated the expansion process, but their relative contributions yet to be distinguished. To separate roles replication Friedreich's ataxia (GAA)n repeats, we designed two yeast genetic systems that utilize a galactose-inducible GAL1 promoter contain these either transcribed or nontranscribed region selectable cassette. We found large-scale repeat expansions can occur lack transcription. Induction strongly elevated rate both systems, indicating active transcriptional state rather than through per se affects this process. Furthermore, defects increased irrespective state. present model which state, linked nucleosomal density region, acts as modulator expansions.