Fig. 3: During UJT but not pEMT, cellular alignment and cellular migration organize into cooperative packs.
a Using a community-finding algorithm (see “Methods” section), cellular orientations were seen to align into orientational packs. Each cell is shown with an orientation director whose length is proportional to AR. Largest orientational packs highlighted in bold colors. Scale bar is 50 µm. c Cells did not exhibit large structural packs when jammed or during pEMT at any time point. (n = 3 donors from independent experiments). During UJT, by contrast, cells aligned into packs whose median size progressively grew in cell number from 24 to 72 h. Left panel: mean ± SEM for n = 3 donors; right panel: measurements for each donor, delineated by symbol shape. b Using velocity fields obtained by optical flow and the same community-finding algorithm, cellular motions were seen to organize into oriented migratory packs. Velocity vectors are shown for a 2-h period, with members of the largest dynamic pack highlighted in black. Scale bar is 100 µm. d In jammed layers dynamic packs remained relatively small at all time points (n = 4 donors from independent experiments). During pEMT dynamic packs were substantially larger at 24 h but returned to baseline by 48 h. During UJT, by contrast, dynamic packs grew dramatically in size and remained elevated out to 72 h. Left panel: mean ± SEM for n = 4 donors; right panel: measurements for each donor, delineated by symbol shape. See also Supplementary Table 1 and online Source Data file. *p < 0.05, vs. control; #p < 0.05, UJT vs. pEMT, color-coded according to which sample is referenced; one-way ANOVA followed by post-hoc multiple comparisons with Bonferroni correction.
