Fig. 3: MCs use slow integrin-dependent migration in tissues and 3D matrix.
From: Slow integrin-dependent migration organizes networks of tissue-resident mast cells
a, Tracing slow MC migration in the dermal tissue of 6- to 12-week-old mice. Tln1ΔMC and control mice carried the Ubow reporter transgene. b, Comparative analysis of ear skin whole-mount tissue of 8-week-old WT Ubow and Tln1ΔMC Ubow mice. All YFP+ and CFP+ cells were positive for the pan-MC marker avidin (purple). Dermal tissue was counterstained with collagen IV (white) to assess basement membranes and overall tissue geometries. c, Top, representative images of cell center coordinates after computational rendering using ClusterQuant2D software, which was used to analyze the formation and sizes of unicolored MC clusters. Bottom, quantification of YFP+ and CFP+ cluster frequencies sorted by cluster size. Two-cell clusters were not included in the analysis. Data are from n = 3 (WT) and n = 4 (Tln1ΔMC) mice with two to three imaging fields of view per mouse. d–f, WT and Tln1−/− BMMCs in 3D Matrigel were monitored over 3 d. d, Brightfield images at t = 72 h. e, Quantification of the cell cluster area at t = 72 h. Each dot represents the growth area of one MC cluster (n = 23 (WT) and 20 (Tln1ΔMC)) obtained from three independent experiments. Bars display the medians; ***P < 0.0001. Data were analyzed by two-sided U-test. f, Analysis of MC cluster growth area over time. Dots show individual clusters (mean ± s.d.; n = 10 clusters from one experiment). g–i, BMMC migration in 3D Matrigel was recorded by live-cell microscopy over 4 d. g, Quantification of the average cell speed over the first 36 h. Dots are values of individual cells (n = 20 randomly chosen cells per genotype). Bars display the means; ***P < 0.0001. Data were analyzed by two-sided U-test. Images were acquired by spinning-disk confocal microscopy of Lifeact–GFP-expressing WT and Tln1−/− BMMCs migrating in Matrigel. h, Proliferation of individual Tln1−/− BMMCs (colored numbers) but hardly any movement out of cell clusters. i, Tracking analysis revealed intermittent phases of movement and cell division, which distributes WT cells in the gel. Colored numbers indicate parent and descendant cells; scale bars, 100 µm (b and d), 5 µm (g), 50 µm (h and i) and 20 µm (i, inset).
