Coro1A is required for efficient migration of PMNs but is dispensable for GPCR-proximal Ca²⁺signaling of PMNs. (A-B) Mechanotactic migration of Coro1A^+/+ and Coro1A^−/− PMNs under flow (1 dyne/cm²) using microflow chambers coated with immobilized fibrinogen or rmICAM-1 in the presence of 10 µM of fMLP. (A) Single-cell migration tracks after 10 minutes of flow. Arrows indicate direction of flow. (B) Mean migration velocity and mean Euclidean distance (n = 4, fibrinogen; n = 3, rmICAM-1). Mean ± standard deviation. (C-E) Chemotactic migration of Coro1A^+/+ and Coro1A^−/− PMNs toward gradients of 100 ng/mL of rmCXCL1, 10 µM of fMLP, or 100 nM of LTB₄ using Zigmond chambers. Gradient cones indicate orientation of gradients. (C) Single-cell migration tracks. (D) Mean migration velocity and mean Euclidean distance are graphed (n = 3). Mean ± standard deviation. (E) Rose diagrams. The area of each sector is proportional to the frequency of the migration vectors of tracked Coro1A^+/+ and Coro1A^−/− PMNs pointed in the respective direction in response to gradients of rmCXCL1, fMLP, or LTB₄. Rose plots shown are representative of 3 independent experiments. (F) Ca²⁺ signaling in Coro1A^+/+ and Coro1A^−/− PMNs upon stimulation with 10 µM of fMLP (left) or 100 nM of LTB₄ (right). Cytosolic Ca²⁺ concentration was measured in Fura-2 AM-labeled PMNs. Relative concentration was determined in percentage of maximum Ca²⁺ response upon treatment with 12 µM of ionomycin. Data are representative of 4 independent experiments. *P < .05.