ULTRASTRUCTURE OF CULTURED PLASMODIUM-GALLINACEUM OOKINETES - COMPARISON OF INTACT STAGES WITH FORMS DAMAGED BY EXTRACTS FROM BLOOD FED, SUSCEPTIBLE AEDES-AEGYPTI

  • 1 January 1979
    • journal article
    • research article
    • Vol. 36  (4) , 323-334
Abstract
The ultrastructure of intact, mature and immature ookinetes of P. gallinaceum is compared with corresponding stages which were damaged by A. aegypti extracts prepared during blood digestion. Some new details of ookinete ultrastructure are revealed. The composition, development and mode of formation of the pellicle of plasmodial ookinetes is similar to that of other sporozoans. The pellicle is composed of 3 membranes, develops in the growing protrusion of the retort-shaped early ookinete and its inner layer is probably formed by fusion of peripheral vesicles. Staining with ruthenium red indicates the presence of a surface coat. Furthermore Golgi-like structures and lysosomes can be observed. After exposure to A. aegypti extracts the parasites exhibit signs of severe cell damage and degeneration, such as disintegration and vacuolization of the cytoplasm. Damage of the plasma membrane is demonstrated by its permeability for ruthenium red. Cell damage is particularly prominent in those cell parts which are not covered by the pellicle and suggests a protective function for this structure.