Synthesis of DNA during the asexual cycle of Plasmodium falciparum in culture.

DNA synthesis in cultures of tightly synchronized, developing, asexual forms of Plasmodium falciparum began during the early trophozoite stage between 29.5 and 31 h after parasite invasion and continued through most of the remainder of schizogony. DNA synthesis was inhibited by both hydroxyurea and aphidicolin. Aphidicolin had a biphasic inhibitory effect on DNA synthesis with a portion of the DNA synthesis being considerably more resistant to inhibition. These agents did not block the morphological maturation of ring forms to early trophozoites but did block further maturation of trophozoites and schizonts.