Involvement of EhARPC1 in pseudopod formation and phagocytosis.

(A) The montage shows a time series of motile trophozoites expressing GFP-EhARPC1. A number of pseudopods in different directions can be visualized and are marked by white arrowheads. Bar represents 10μm. (B) Time course of intensity of GFP-EhARPC1 (ROI) was determined at leading edge of amoeba. Snapshot of ROI selected is shown at two time points where GFP-EhARPC1 fluorescent intensity increases and then gradually decreases. (C) Quantitative determination of phagocytic events was carried out in 25 cells by randomly selecting them and counting the number of phagocytic cups, closed cups before scission, and phagosomes present in these cells. (D) E. histolytica trophozoites actively phagocytosing RBCs, incubated for different times and representing different stages of phagocytosis were stained for EhARPC1 (Alexa 488) and actin (TRITC phalloidin). Arrowhead indicate phagocytic cups, asterisks mark closure of cup before scission, stars mark phagosomes, and yellow arrowheads indicate RBCs in the process of phagocytosis. Bar represents 10μm.