<em>C. elegans</em> (IMAGE) University of Konstanz Caption Left: How the ribozyme-based genetic switch works. A self-cleaving tetracycline-dependent ribozyme results in mRNA decay and down-regulation of gene expression. Adding tetracycline inhibits ribozyme activity, which stabilizes the mRNA and induces gene expression. Right: Application of the genetic switch in the animal research model C. elegans. Tetracycline-induced expression of the fluorescence (mCherry)-tagged Huntingtin protein (Htt) with an abnormally long polyglutamine sequence that causes Huntington's disease in humans. Htt aggregates, which are typical of Huntington's disease, can be observed to form in the animal model. Credit L. A. Wurmthaler, M. Gamerdinger, J. S. Hartig Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.