Figure 11.

Germinal crescent PGCs are actively motile in the presence of laminin. Captured frames from live confocal microscope imaging of an HH4 [Tg(hUbC:H2B-Cerulean-2A-Dendra2)] quail embryo that was injected with an antibody against laminin (ab31-2). This antibody was directly conjugated to AlexaFluor 555, red). The 20x images are maximum intensity projections of 3 optical slices (3.2 μm each) taken from the dorsal aspect at 1.5 min intervals. Cell nuclei = H2B-Cerulean (blue), cell bodies = Dendra2 (green). PGCs (clump, white arrow), are brighter than the surrounding cells. Bounding box indicates the region shown in the lower right corner of the last five frames. The laminin fibril bundle (yellow arrow) has a smooth wave shape at 47 min. At 50–57 min the fibril bundle is condensed, pushing it upwards into a sharp peak. Later, as the tissue expands from 65 to 71 min, the bundle resumes its prior form. Scale bar = 25 μm. View the full movie in Video S2.