Figure 5—figure supplement 1.

(A) labeled with antibodies against GFP (fli1a:GFP, blue) IB4 (red) and Mpx (green) showing no Mpx-positive neutrophils on the ventricle only resident IB4-positive macrophage (red arrowhead). (B) 1 day post cryoinjured (dpc) heart (mild injury) labeled at the same time shows a massive increase in Mpx-expressing neutrophils and IB4-positive macrophage on the ventricle and concentrated at the wound site (demarked with yellow dashed line). In many cases, IB4-positive macrophage have engulphed Mpx-positive cells or debris as indicated with green staining within red-labeled macrophage cells (yellow arrowhead, inset within the wound site). (C, n = 8) Uninjured zebrafish heart labeled with antibodies against GFP (Fli:GFP, green) and Mpx showing no Mpx-positive neutrophils on the ventricle or BA, including within the lymphatic vessels on the BA (green arrowheads). (D, n = 6) 7dpc heart showing Mpx-positive cells (white, white arrowheads) on the ventricle, in the wound site (yellow dashed line) and on the BA, within and on the lymphatic vessels. (E and F) High resolution imaging of lyve1:GFP -positive vessels (green, blue outline) on the BA of a 3dpc heart with Mpx-positive neutrophil (red, red arrowhead) within the lymphatic vessel (see Figure 5—videos 4 and 5). (G) Graph showing quantification of increase in Mpx-positive cells within the BA lymphatic vessels of 1dpc (n = 4) and 7dpc (n = 5) zebrafish hearts compared to those of uninjured hearts (n = 5). *p<0.05, unpaired t-test, Mean and SD. Scale bars 200 μm and 50 μm (insets).