Fig. 3.

Larvae contain pericardial cells but lack periostial hemocytes. a Dissected larval dorsal abdomen with fluorescently labeled pericardial cells (IgG 568 nm; red). Nuclei were stained blue with Hoechst 33342, and the pericardial cell clusters are delineated by the whiskers. b A single set of pericardial cell clusters (red) of a larva, showing the large posterior-most pairs of cells and the gap that forms at a location that is just ventral of each ostium (asterisk) of the heart (phalloidin; green). c, d A dissected adult abdomen showing pericardial cell clusters in the same locations as in larvae. Images in panels a and c were assembled by stitching three higher resolution images. e, f Co-labeling of pericardial cells (IgG 488 nm; green) and hemocytes (CM-DiI; red) of a larva, displayed both as an Extended Depth of Focus (EDF) image (e) and a three-dimensional (3D) volume view image (f). Segmental hemocyte bands (rectangles) lie dorsal to the pericardial cells, and no hemocytes are present at the periostial regions (oval) that flank the ostia (asterisks). g, h EDF (g) and 3D volume view (h) fluorescence images showing that the segmental hemocytes (red) of a larva are dorsal to the heart (green) and distant from the ostia (asterisks). No hemocytes are present at the periostial regions (ovals). i, j EDF (i) and 3D volume view (j) fluorescence images of a larva showing that the segmental hemocytes (red; rectangle) lie dorsal to the swim muscles (green). Directional arrows: A anterior, P posterior, D dorsal, V ventral, L lateral