Figure 4. Galvanin is sufficient to enable cathodal electrotaxis.

A. Flow cytometry histograms showing expression of human Galvanin-GFP in two clonal MDCK cell lines. The parental MDCK cell line is not fluorescent and their intensity values reflect autofluorescence (see Methods). B. Fluorescence micrographs showing localization of Galvanin-GFP toward the anode when MDCK cells are exposed to an electric field (300 mV/mm). left: example of a single cell. right: example of a cell cluster. C. Relative cell trajectories of MDCK cells exposed to an electric field (300 mV/mm) over three hours (5-minute imaging interval). A subset of trajectories is shown (100 per condition). D. Average speed along the electric field direction. Each data point represents the speed averaged across cells within a single imaging field of view (40 fields of view across two sample preparations; 971–1760 cells per condition), while the boxplot extends from the first to third quartiles with a line at the median. Asterisks indicate statistical significance between the 300 mV/mm and 0 mV/m conditions (p-value < 0.0001, two-sided Mann–Whitney U test).