Primitive myeloid migration time-lapse video microscopy. (A) Experimental setup, stage-14 to -16 anterior ventral blood islands were transplanted from microruby-injected to noninjected embryos. Transplanted cells become migratory and leave the transplant to colonize the embryo in 4 to 8 hours. Throughout this period, primitive myeloid cells show different behaviors (Videos S1Video 2. Lateral migration 4× (MOV, 4.82 MB)–S3). (B,C) Stage-18 brightfield/fluorescent composite of transplanted embryos. (D,E) Stills from supplementary movies. (Panel D and Video S2) Ventral view of primitive myeloid cells leaving the transplanted aVBI with “blebbing” behavior and low migratory speeds. (Panel E and Video S3) Primitive myeloid cells leaving the transplanted aVBI (stage 26, lateral view). At this stage, cells acquire elongated cell morphology and higher motility. Large dashed line shows the embryo contour, and the light dashed square shows the enlarged region shown in still frames. Colored arrowheads point and track the same cell. (D,E) Anterior view is shown to the left; dorsal, to the top. Time is shown in minutes. Images in panels B and C were obtained on a fluorescence stereoscope Leica MZ FLIII (Wetzlar, Germany) attached to a Sony CCD camera DXC-950 image capture system controlled by Northern Eclipse software 7.0 (Empix Imaging, Mississauga, ON). For panels D and E, the same image capture system was attached to an Olympus IX70 inverted fluorescent microscope; 0.1× MMR was used as imaging medium. (D) Total magnification 300× objective (Olympus LCPlan 20×/0.4 NA). (E) Total magnification 40× objective (Olympus UPlanFL 4×/0.13 NA). Photoshop CS2 (Adobe Systems, San Jose, CA) or ImageJ 1.38 (National Institutes of Health, Bethesda, MD) were used for image or time-lapse video processing.