A Riboswitch-based Inducible Gene Expression System for Trypanosoma brucei.

Generation of conditional mutants in Trypanosoma brucei can be done by the use of RNA interference (RNAi). However, RNAi frequently produces off target effects. Here, we present an alternative strategy in which the glmS ribozyme is inserted in the C-terminal region of one allele of a GOI and effectively knocks it down in response to the presence of glucosamine in the culture medium. Using several endogenous genes, we show that the glmS ribozyme cleaves the mRNA in vivo leading to reduction in mRNA and protein expression following glucosamine treatment in both T. brucei procyclic and bloodstream forms. Glucosamine-induced ribozyme activation can be rapidly reversed by removing the inducer. In summary, the glmS ribozyme could be used as a tool to study essential genes in T. brucei.