Figure 4. Validation and robustness of morphological motif detection.

(a) A multiclass detector applied to cells derived from a human melanoma xenograft cultured in mice (representative of 9 cells). Filopodia are shown blue, blebs are shown red, and areas with neither filopodia nor blebs are shown gray. (b) Validation measures for a bleb detector (left) trained on 19 MV3 melanoma cells, a filopodia detector (center) trained on 13 HBEC cells, and a lamellipodia detector (right) trained on 13 dendritic cells. TP, TN, FP, and FN are abbreviations for true positive, true negative, false positive, and false negative respectively. (c) The F₁ score as a function of the number of cells trained on. The red line indicates the mean F₁ score averaged over a maximum of 100 sets of cells, whereas the gray dots show individual sets of cells. (d) A bleb detector trained on the MV3 melanoma cell line applied to cells derived from a human melanoma xenograft cultured in mice (representative of 24 cells). (e) A filopodia detector trained on xenograft-derived melanoma cells applied to HBEC cells (representative of 13 cells). A filopodia detector trained on HBECs applied to the cell on the left is shown in Supplementary Fig. 5 and applied to the cell on the right is shown in Fig. 3. (f) Blebs detected on wildtype, cofilin-1 knock out, and Wave2 knockout U2OS cells in 3D collagen. (g) For these three cell types, the percentage of the surface that is blebby. We analyzed 19 wildtype, 15 cofilin-1 knockout, and 14 Wave2 knockout cells.