eLife Assessment
This important article describes a meticulously-developed improved strategy for generation of functionally null mutants in Leishmania spp. via cytosine base editing, with reduced background toxicity and enhanced efficiency relative to a previously-described method. The authors show use of the strategy in a small-scale loss-of-function screen, providing compelling evidence that large-scale screens will be possible. The newly developed tools will be of great interest to researchers working with Leishmania and beyond.