Fig. 6
Controls of galvanotactic behavior in Amoeba proteus. a 50 amoebae (experimental replicates: 6, number of cells per replicate: 7–10) were subjected to a controlled electric field (galvanotaxis during 30 min) after being exposed to nFMLP peptide for at least 30 min. All cells exhibited normal galvanotaxis, that is, migration towards the cathode, confirming that exposure to nFMLP was not able to elicit changes in the normal galvanotactic response of Amoeba proteus by itself. b 25 amoebae (experimental replicates: 2, number of cells per replicate: 11–14) were subjected to a galvanotactic stimulus during 30 min, next, the cells were placed in a Petri dish filled with Chalkley’s medium for 3 min and then exposed to another identical electric field with inverted polarity c (experimental replicates: 2, number of cells per replicate: 11–14). All the amoebae showed a normal galvanotactic behavior in both occasions b, c. d Distribution of the cosines of displacement angles for all the trajectories under galvanotaxis (a, b and c). In order to represent the preference towards a pole for the three controls simultaneously, the signs of the cosines of displacement angles of the trajectories represented in panel c were inverted (associating the anode to negative cosines and the cathode to positive values). As it was observed previously in Fig. 3e, 100% of the displacement cosines were positive, indicating a strong preference towards the cathode when the electric field was active. “N” total number of cells, “Er” experimental replicates, “nr” number of cells per replicate, “t” galvanotaxis time, “ + ” anode, “−” cathode. Both the x and y axis show the distance in mm, and the initial location of each cell has been placed at the center of the diagram
