Figure 6

Exposure to copper induces migration response of macrophages in the olfactory organ. (A-A^‴) 5-dpf Tg(mpeg1:mCh);Tg(OMP:YFP) larva frontal view. Imaging was initiated at time 0′. At 14′ (A′), larvae were exposed to 10 μM of CuSO₄ and imaging continued at times indicated (see Supplementary Video 2 for sequences taken every 2 min). (A″, A^‴) Arrows in (A^‴): non-local macrophages that enter the OO (see Supplementary Video 2). (B–B^‴) Individual 2D-cell tracking of macrophages associated with the OOs before, during, and after copper exposure. Each color represents a different macrophage. (C) Number of macrophages within the OO before and after copper exposure: analysis of three independent videos, (Unpaired t-test, P < 0.05). (D) Speed of macrophages before and after copper exposure (n = 50 macrophages, 1 time lapse; Unpaired t-test, P < 0.001). (E) Total displacement of local and non-local macrophages (Supplementary Video 2) during a 2-h time lapse (n = 51 macrophages, 16 local, 35 non-local; unpaired t-test, P < 0.0001). Scale bars: A = 150 μm. Tracking was done using the ImageJ plugin, MTrackJ. (F) Time course of macrophage movement to the OO (n = 24 larvae. ANOVA, Kruskal–Wallis test, P < 0.0001).