Sex- and stage-specific reporter gene expression in Plasmodium falciparum

Abstract

For malaria transmission, Plasmodium parasites must successfully complete gametocytogenesis in the vertebrate host. Differentiation into mature male or female Plasmodium falciparum gametocytes takes 9–12 days as the parasites pass through five distinct morphologic stages (I–V). To evaluate the signals controlling the initiation of stage- and/or sex-specific expression, reporter constructs containing the 5′-flanking regions (FR) of seven genes with distinct expression patterns through gametogenesis were developed. The regulatory information present in the 5′-FR of each selected gene was found to be sufficient to drive appropriate sex- and stage-specific reporter gene expression. The transformed parasite lines also provide in vivo markers to identify gametocytes at specific stages, including a subpopulation of schizonts that express early gametocyte markers.