The organization of the ookinete and observations on nuclear division in oocysts of Plasmodium berghei

Abstract

Ultramicroscopic features of the ookinete/oocyst transformation in Plasmodium berghei are described. The apical complex of organelles and some pellicular components, believed to be responsible respectively for cell penetration and body form were resorbed into the cytoplasm shortly after the ookinete came to rest under the basal lamina of the midgut wall. Within a single digitate nucleus, spindles at different phases of division were observed with kinetochores in early and late anaphase position. From the number of kinetochores the chromosome complement was estimated at 5–10.