No correlation between cell volume around schizogony start and merozoite number but preserved N/C ratio increase under diluted medium condition.

A Quantification of parasite cell volume over time of time-lapse imaging with P. falciparum 3D7 episomally expressing cytosolic GFP and nuclear mCherry in 0.5x diluted medium with 0.9% NaCl. Parasites were placed in diluted medium conditions 24–30 hours prior to imaging and late trophozoites were selected for movies. Line represents mean and error bar range; grey line shows data acquired in 1x medium (Fig 5). Curves were aligned to schizogony start (0 h). Light green zone indicates range of measured schizont stage durations under diluted conditions. B Comparison of parasite cell volume from A between 0.5x medium (green dots) and 1x medium (grey boxes showing mean, min, max) at pre-schizogony (t−2), schizogony start (t0) and schizogony end (tend). C Correlation of merozoite number against cell volume at pre-schizogony (t−2), D schizogony start (t0) and E schizogony end (tend). Given are Pearson correlation coefficient r and p values. Three cells shown for tend and t0 were not imaged at t−2 F Total nuclear volume for individual cells at t−2, t0, and tend. G Average nuclear volume (total nuclear volume divided by nuclear number) for individual cells at timepoints like in F. H Merozoite number against average nuclear volume at end of schizogony (tend). Given are Pearson correlation coefficient r and p values. I Total nuclear volume divided by cell volume (N/C ratio) for individual cells at timepoints described in F. All error bars represent mean and SEM. Statistical analyses: t-test with Welch’s correction. N = 30 for t−2 and N = 33 for all others from ten independent replicates.