Normal infectivity of sporozoites to hepatocytes in vitro and in vivo. Mutant parasites develop into large, mature liver stages with extensive nuclear division and expression of merozoite specific proteins, such as msp1 and ama1. Most of the parasites arrest growth, however, just before the formation of infective merozoites. Only after intravenously infection of mice with high doses of sporozoites (2x10(5)) some of the mice (3 out of 10) developed blood infections with a greatly prolonged prepatent period (12-14 days).

Plasmei2 sporozoites failed to initiate a blood stage infection (after injection of 5x10(4) purified sporozoites). Abnormal development of liver stages. Growth arrest of late liver stages.