Fig. 2: Integrins control MC network formation and periarteriolar alignment in vivo.
From: Slow integrin-dependent migration organizes networks of tissue-resident mast cells
a,b, Comparative analysis of ear skin whole-mount tissues of adult Tln1ΔMC mice and littermate controls. Endogenous dermal MCs were immunostained with avidin in relation to collagen IV (COL4)-expressing basement membrane structures (a) or dermal vessel types (b). Arterioles (red) and postcapillary venules (green) were classified by differential staining for α-smooth muscle actin (ACTA2) and ACKR1. Representative micrographs of 20 mice per genotype (a) and 5 mice per genotype (b) are displayed. c,d, Analysis of perivascular MC positioning. c, Quantification of MCs in proximity to arterioles, venules and capillaries, which were identified by differential staining for ACTA2 and endomucin. Dots represent individual imaging fields of view (n = 24 (WT) and 24 (Tln1ΔMC)), which came from six 7-week-old mice (arterioles: ***P < 0.0001, two-sided t-test; venules: P = 0.47, two-sided U-test; capillaries: P = 0.15, two-sided U-test); NS, not significant. d, Quantification of arteriolar coverage by MCs. Dots represent individual imaging fields of view (n = 20 (WT) and 20 (Tln1ΔMC)) pooled from five 7-week-old mice; ***P < 0.0001. Data were analyzed by two-sided t-test. e,f, Analysis of MC morphologies in the dermis of adult Tln1ΔMC Rosa26LSL:YFP mice and littermate control Mcpt5-cre+/− Tln1+/+ Rosa26LSL:YFP mice. e, YFP-expressing dermal MCs are displayed in glow heat map (e). Quantification of cell roundness (circularity) was performed for n = 31 cells per genotype, which came from four WT and three Tln1ΔMC mice (f). Bars display the mean; ***P < 0.0001. Data were analyzed by two-sided U-test; scale bars, 100 µm (a), 200 µm (b) and 20 µm (e).
