Fig. 2.

The PVM becomes permeable before its rupture. (A) DIC and fluorescence images of C1-treated schizonts expressing mCherry in the PV. Schizonts in which the fluorescence signal is restricted to the vacuole were classified as nonleaky (∼50% of 561 cells analyzed) or leaky when the fluorescence signal extended into erythrocyte cytosol (∼35%). In ∼15% of the schizonts, the vacuole occupied most of the volume of the infected cell, precluding detection of leakiness; these were classified as ambiguous. Note that the brightest feature in fluorescence is the food vacuole; the PV (dotted line) and erythrocyte (dashed line) are indicated on the DIC panels. (Scale bar, 2 μm.) (B) Graph showing the proportion of leaky cells plotted according to whether they egressed or not during a 30-min recording (total 234 cells from three separate recordings). Error bars, SD. More egressed than nonegressed cells were classified ambiguous as it was not possible to determine leakage, likely due to the PVM being less clearly visible in leaky cells. (C) Selected frames from a time-lapse video of egress. Fluorescence leaks from the PV into the blood cell between the first two depicted frames, ∼20 min before rounding up. Time after removal of the C2 block is indicated. (Scale bar, 2 μm.) Brightness and contrast have been linearly adjusted to the same levels for each of the frames shown. The progressive loss of fluorescence is due to photobleaching.