Controlling gene expression with the Q repressible binary expression system in Caenorhabditis elegans

We establish the first transcription-based binary gene expression system in C. elegans using the recently developed Q system. This system, derived from genes in Neurospora crassa, uses the transcriptional activator QF to induce the expression of target genes. Activation can be efficiently suppressed by the transcriptional repressor QS, and suppression in turn can be relieved by the non-toxic small molecule, quinic acid (QA). We used QF/QS and QA to achieve temporal and spatial control of transgene expression in various tissues in C. elegans. We further developed a Split Q system, in which we separated QF into two parts encoding its DNA-binding and transcription-activation domains. Each domain shows negligible transcriptional activity when expressed alone, but co-expression reconstitutes QF activity, providing additional combinatorial power to control gene expression.