Fig 4. Lake-sampled cells display phototactic behavior and higher motility than domesticated cells.

Ratios of motile vs non-motile cells for (A) lake-sampled and (B) laboratory-grown cells after 0, 30 and 90 min of light exposure in a half-shaded, half-illuminated microfluidic chip (see S6 Fig in S1 File). Two-way ANOVA, p < 0.01; post hoc Tukey test; asterisks indicate statistically significant differences. Error bars represent standard deviation (N = 3).