THE PLASMODIUM CELL-CYCLE - FACTS AND QUESTIONS

The Plasmodium life-cycle contains within it several discrete cell-cyc les whose molecular controls are very poorly understood. Of the five ( or more) periods of DNA synthesis within the P. falciparum life-cycle, that associated with erythrocytic schizogony has been studied in the greatest detail and el en here, controversy exists as to the precise n ature and timing of the major, cell-cycle events. Thus, while it is cl ear that DNA synthesis (S phase) starts around 28-31 h after merozoite invasion (soon after the appearance of pigmented trophozoites), neith er flow-cytometric nor precursor-incorporation studies have provided a definite answer as to whether rapid and successive G(2) and then M (m itotic) phases occur during schizogony. These and other problems of in terpretation of the P. falciparum cell-cycle are considered.