PLASMODIUM-FALCIPARUM - HIGHLY MOBILE SMALL VESICLES IN THE MALARIA-INFECTED RED-BLOOD-CELL CYTOPLASM

A dynamic population of small vesicles within the cytoplasm of live ma laria-infected red blood cells has been studied using a laser scanning confocal microscope. Acridine orange was used to follow the movement of vesicles within the infected red blood cell cytoplasm, including th e budding of vesicles from the malarial parasite. These highly mobile vesicles are found predominantly in mid- to late ring-stage parasites and are almost entirely absent from young rings and mature trophozoite s. Since the known parasite modifications of the red blood cell plasma membrane in mid-ring- to early trophozoite-stage parasites correlates with the appearance of acridine orange-staining vesicles, these vesic les may be an important component in the transport of parasite protein s across the infected red blood cell cytoplasm. (C) 1994 Academic Pres s, Inc.