Comparative analyses of these genetic mutations will allow the role of CUG and CTG expansions in the etiology of DM to be defined. Our results demonstrate that CTG expansion is bi-modal, that is, repeat expansion can occur either in small incremental steps or as large discrete expansion events. We demonstrate that repeat length and the levels of the hairpin incising enzymes influence the probability and amplitude of CTG expansion. Our data suggests that formation of DNA hairpins or double-strand breaks maybe important intermediates in triplet repeat expansion. In other experiments we hope to focus on the role of loop and double-strand break repair pathways in eliciting CTG expansions in somatic cells and during gametogenesis.
Mice lacking the myotonic dystrophy kinase develop a late onset myopathy.
CTG repeats show bi-modal amplification in E. coli. Cell 95, 531-540. Atrioventricular conduction abnormalities are observed in mice lacking the myotonic dystrophy kinase. J. Clin Invest. Localization of the site of conduction abnormality in a mouse model of myotonic dystrophy.