Figure 4.
Embryonic pulmonary mesenchymal cells exhibit spatially patterned migratory behaviors and cortical tension
(A) Snapshots from time-lapse analysis of Dermo1-Cre;Confettifl/lungs isolated at E11.5 showing a bifurcating epithelial bud surrounded by sparsely fluorescently labeled mesenchymal cells.
(B) Plot of cell trajectories from tracking time-lapse analysis of Dermo1-Cre;Confettifl/lungs isolated at E11.5. Tracks are color-coded based on time-point. Shaded areas show mesenchymal compartments and smooth muscle regions. Inset in top left corner shows a snapshot of the time-lapse from which the cell tracks are taken.
(C) Mean speed of tracked cells of each mesenchymal cell type (n = 6 time-lapses, n = 280 cells total). Error bars show SD
(D–F) Snapshots from time-lapse analyses of Dermo1-Cre;Confettifl/lungs isolated at E11.5 showing a mesenchymal cell migrating from the sub-mesothelial to the sub-epithelial mesenchyme (D) and vice versa (E), showing a sub-epithelial mesenchymal cell elongating and presumably differentiating into smooth muscle (F). Yellow arrowhead indicates tracked cell, dashed line indicates the epithelium, and dotted line indicates the mesothelium.
(G and H) Percentage of tracked cells from the sub-mesothelial (G; n = 51) or the sub-epithelial (H; n = 203) mesenchyme that stay within their original compartment, cross compartments, or elongate, presumably differentiating into smooth muscle.
(I) Percentage of tracked smooth muscle cells that were already smooth muscle or that were observed to differentiate from sub-epithelial mesenchymal cells (n = 26).
(J) Schematic of VinTS. Vh is vinculin head, Vt is vinculin tail.
(K) Fluorescence intensity of VinTS in E12.5 lung and lifetime of TFP donor along mesenchymal cell edges.
(L) Fluorescence lifetime of sub-epithelial and sub-mesothelial mesenchymal cells (n = 6 samples, n = 261–282 cells). Boxes show 25th and 75th percentiles, center lines show median. Scale bars show 50 μm. Groups were compared using two-sided t-test and Bartlett’s test for unequal variances. ∗∗∗ indicates p<0.0001 for t-test and # indicates p<0.05, ## indicates p<0.001, and ### indicates p<0.0001 for Bartlett’s test