Regulators of gametocytogenesis and the sexual stage of the life cycle.

<p>Differentiation of asexual blood stage parasites into gametocytes occurs in the vertebrate host. Ingestion in a mosquito blood meal results in activation of the gametocytes in the lumen of the gut, stimulated by an increase in Ca²⁺, a drop in temperature, and the presence of the mosquito-derived xanthurenic acid, leading to the production of male and female gametes. Fertilization and fusion of these gametes results in zygote formation. Eventual elongation of the zygote leads to the final stage of the sexual cycle, a highly motile ookinete. Genes involved at each stage of the process (as suggested by a number of functional analyses) and time spans for each stage are indicated.