The apicoplast: now you see it, now you don’t

[Display omitted] •Discovery of the apicoplast is reviewed.•Function and biogenesis of the apicoplast is reviewed.•Deletion of the apicoplast by chemical supplementation of in vitro cultured human malaria parasites is reviewed.•Ongoing questions and potential of the apicoplast for therapy is explored. Parasites such as Plasmodium and Toxoplasma possess a vestigial plastid homologous to the chloroplasts of algae and plants. The plastid (known as the apicoplast; for apicomplexan plastid) is non-photosynthetic and very much reduced, but has clear endosymbiotic ancestry including a circular genome that encodes RNAs and proteins and a suite of bacterial biosynthetic pathways. Here we review the initial discovery of the apicoplast, and recount the major new insights into apicoplast origin, biogenesis and function. We conclude by examining how the apicoplast can be removed from malaria parasites in vitro, ultimately completing its reduction by chemical supplementation.