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Myotonic dystrophy in transgenic mice expressing an expanded CUG repeat
A Mankodi1, E Logigian, L Callahan
1Department of Neurology, School of Medicine and Dentistry, University of Rochester, Box 673, 601 Elmwood Avenue, Rochester, NY 14642, USA.
Science (New York, N.Y.)
|September 8, 2000
Summary
Myotonic dystrophy (DM) is caused by expanded CTG repeats in DMPK gene mRNA. Transgenic mice expressing these expanded repeats developed DM symptoms, confirming RNA gain of function in disease.
Area of Science:
- Genetics
- Molecular Biology
- Neurology
Background:
- Myotonic dystrophy (DM) is a common adult muscular dystrophy.
- It stems from CTG repeat expansion in the DMPK gene's 3' untranslated region.
- The mutant mRNA accumulates in the nucleus.
Purpose of the Study:
- To investigate if expanded CUG repeats in mRNA are sufficient to cause DM.
- To explore the role of RNA gain of function in DM pathogenesis.
Main Methods:
- Expressed untranslated CUG repeats in unrelated mRNA within transgenic mice.
- Compared phenotypes between mice with expanded and non-expanded repeats.
Main Results:
- Mice expressing expanded CUG repeats exhibited myotonia and myopathy.
- Mice with non-expanded repeats did not develop these symptoms.
Conclusions:
- Expanded CUG-repeat transcripts are sufficient to induce a DM phenotype.
- This supports a gain-of-function mechanism involving RNA in DM pathogenesis.
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