Discussion

RNA interference has been particularly effective for gene knockdown and functional studies in the African trypanosome. Such genetic approaches used in high-throughput mode can be particularly powerful and we have found this to be the case for RNA Interference Target sequencing, or RIT-seq. Genes can be rapidly linked to phenotypes, even when nothing is known about mechanism at the outset. RIT-seq was initially used to generate genome-scale loss-of-fitness profiles, facilitating drug-target prioritization. Used in combination with antitrypanosomal drugs, RIT-seq then revealed the genes associated with drug-resistance. Defective drug uptake emerged as a prominent feature and one particular transporter, an aquaglyceroporin, was found to be responsible for the most widespread form of resistance in trypanosomiasis patients. Other examples of how we are using genetic screens to develop our understanding of druggable biology will be presented.