METABOLIC CHANGES OF THE MALARIA PARASITE DURING THE TRANSITION FROM THE HUMAN TO THE MOSQUITO HOST

Plasmodium falciparum is an obligate human parasite that is the causat ive agent of the most lethal form of human malaria. Transmission of P. falciparum to a new human host requires a mosquito vector within whic h sexual replication occurs. P. falciparum replicates as an intracellu lar parasite in man and as an extracellular parasite in the mosquito, and it undergoes multiple developmental changes in both hosts. Changes in the environment and the activities of parasites in these various l ife-cycle stages are likely to be reflected in changes in the metaboli c needs and capabilities of the parasite. Most of our knowledge of the metabolic capabilities of P. falciparum is derived from studies of th e asexual erythrocytic cycle of the parasite, the portion of the paras ite life cycle found in infected humans that is responsible for malari al symptoms. Efforts to control transmission and to understand the som etimes unique biology of this parasite have led to information about t he metabolic capabilities of sexual and/or sporogonic stages of these parasites. This review focuses on comparing and contrasting the carboh ydrate, nucleic acid, and protein synthetic capabilities of asexual er ythrocytic stages and sexual stages of P. falciparum.