N. gruberiamoebae were imaged at a rate of 0.11 s/frame, and vacuole area was measured for each frame during expulsion. Periods of rapid expulsion were isolated using a threshold of 14 μm2/s, and the first time point when rapid expulsion occurred was set to 0. Vacuoles with expulsions lasting for at least 5 consecutive time points were analyzed. On the plot of contractile vacuole area over time (left), each point represents the area of the contractile vacuole bladder (n = 4 vacuoles from 4 different cells), and the linear regression trendline and R2 values are shown. The residual plot (right) is shown to demonstrate the suitability of the linear model.
