Fig. 6

(adapted from Zengel et al.; [68]. Accumulated distance from origin to end position is indicated as a red line. Displacement as minimum distance between origin and end position is depicted with the blue dashed line. Mean velocity is calculated from the ratio of accumulated distance and time. Directness as ratio of displacement and accumulated distance indicates a measure of how direct a cell migrates from its origin to its end position. A directness value tending towards 1 indicates a straight migration from the start to the end position. Thus, an increase in directness index indicates that cells more directly migrate from their origin to their end position. (B) Cartoon depicting the experimental design to study migration characteristics in neutrophils isolated from Ly6G-Cre JAK2^+/VF and CALR^+/del mice in comparison to their corresponding WT controls. Created with Biorender.com. (C-F) Microfluidic chambers were coated with recombinant mouse ICAM-1 and VCAM-1. tdTomato expressing neutrophils isolated from Ly6G-Cre JAK2^+/VF and JAK2^+/+ mice were seeded and time lapse recording of cell migration was started. Neutrophils isolated (200 tdTomato⁺ neutrophils investigated) from Ly6G-Cre JAK2^+/+ and JAK2^+/VF mice (each n = 4) exhibited the following migration parameters: accumulated distance of 96.2 μm compared to 81.9 μm, displacement of 13.6 μm compared to 9.3 μm, mean velocity of 0.026 μm/sec compared to 0.022 μm/sec, and directness index of 0.14 compared to 0.11. (G-J) Migration parameters obtained in 150 tdTomato⁺ neutrophils investigated in Ly6G-Cre CALR^+/+ and CALR^+/del mice (each n = 3). Data are shown as mean ± SEM. **p ≤ 0.01, ****p ≤ 0.0001 (unpaired, two-tailed t-test)