Tracking collective cell motion by topological data analysis
Fig 17
(a)-(b) Betti numbers versus filtration parameter diagrams for Fig 14(a) (blue asterisks, from S1 Data) and 14(b) (magenta circles, later time in the AMA experiment, from S2 Data) show that the number of clusters and holes in the interface between aggregates increases with time. (c)-(d) Same for the numerical simulations considered in Fig 16(e)–16(h) corresponding to the leftmost (S3 Data) and rightmost (S4 Data) panels in Fig 13. As a result of island formation and motion, which increases with time, Panels (a) and (c) show that the number of components decreases more slowly with r for the later time. The peaks in Panels (b) and (d) are similar for r below 20. In both cases, the interfaces formed at the later time display larger numbers of holes with larger sizes as a result of island formation. The additional peaks in Panel (b) near r = 40 correspond to islands that have already penetrated further inside the other cell population in the experiment.