Figure 2.

Fraction of cells moving through channels with bifurcations. (A) Calculated fractions of cells passing through each bifurcation of a five-bifurcations channel, assuming constant 'orientation factor' throughout the channel. Calculated values for orientation factors between 0.5 (random decisions) and 1 (always through the channel) are represented in 0.02 increments. (B) Experimental results show the fraction of PC9 cells passing through each bifurcation in the presence (left panel) and absence of glutamine (right panel). For each condition, the navigation of cells in the presence (filled black circles) and absence of glucose (empty gray circles) are presented in the same panel. We analyzed N = 767 (glutamine and glucose present), 622 (glutamine, no glucose), 312 (no glutamine, glucose), 351 (no glutamine, no glucose) cells that entered the migration channels; N = 7, 4, 3, 5 independent experiments, respectively). The dotted lines are a guide for the eye. (C) Glutamine emerges as the key factor in the differences in the orientation of PC9 cells, with significant differences between conditions with and without glutamine. One symbol is one experiment. The significance of differences was evaluated using ANOVA, * p < 0.05, ** p < 0.001. (D) The absence of glutamine, but not the absence of glucose, reduces the orientation of moving HMEC cells. One symbol is one experiment. The significance of differences was evaluated using ANOVA.