DIFFUSION OF MICROINJECTED MARKERS ACROSS THE PARASITOPHOROUS VACUOLEMEMBRANE IN CELLS INFECTED WITH EIMERIA-NIESCHULZI (COCCIDIA, APICOMPLEXA)

Cells infected with the intracellular parasite Eimeria nieschulzi were microinjected with lucifer yellow (457 Da), biocytin lucifer yellow ( 850 Da) and dextranrhodamine (10,000 Da). Immediately after injection of a mixture of the markers into the host cell cytoplasm, a differenti al diffusion pattern was observed in trophozoites and schizonts. Lucif er yellow and biotin lucifer yellow were seen to enter the parasitopho rous vacuole, whereas the dextran was excluded. Since these markers ca nnot permeate cell membranes, this suggests that the Eimerian parasito phorous vacuole acts as a molecular sieve. This method allows the visu alization and further characterization of the parasitophorous vacuole in living cells.