An improved method for the in vitro differentiation of Plasmodium falciparum gametocytes into ookinetes.

Background Ookinete is the form of the malaria parasite that invades the mosquito midgut epithelium to initiate sporogony. Differentiation of ingested gametocytes into ookinetes in the mosquito midgut lumen and subsequent interaction with the lumenal surface of the midgut epithelium in preparation for invasion is a complex and multi-stepped process. To facilitate the study of these events in detail it is necessary to produce sufficient numbers of pure, fully mature and functional ookinetes. However, production of even a small number of Plasmodium falciparum ookinetes in vitro has proven to be a daunting task. Consequently, over the past four decades our collective understanding of the biology of this parasite form remains sorely deficient. This article reports on investigations of five different ookinete media, in an effort to improve the in vitro transformation efficiency of P. falciparum gametocytes into mature ookinetes and their infectivity of the mosquito midgut.