File:Embryogenesis-of-the-First-Circulating-Endothelial-Cells-pone.0060841.s002.ogv

English: A time-lapse recording made at one frame per second (fps) in a local Region of Interest (ROI). The ROI is an area (825×675 µm) that was extracted from a wide-field recording, showing an extra-embryonic capillary bed in a HH 16 Tie1-YFP embryo. This movie demonstrates a number of endothelial cell behaviors. The streaks that appear to move at very high speed are YFP tagged endothelial cells moving at the rate of blood flow. Other fluorescent cells or small cellular clusters move at variable rates, many in a saltatory fashion characterized by rapid, sequential, starts-and-stops. The white circles at the 10.8-to-10.9 time-point highlight the journey of a cluster of Tie1-YFP endothelial cells percolating through the ROI. Note that the encircled cluster moves through the vascular bed slowly compared to freely flowing blood; further, the cluster appears to become trapped in bottlenecks as it courses through the small bore lumens. It is useful to stop the recording and manually advance frame-by-frame using the QuickTime™ software controls in order to observe events of interest. Playing the recording backwards also facilitates comprehension of the various behaviors. The recording rate is 59 frames per minute or about 1.0 second between frames. The compression algorithms used in creating this movie result in a loss of resolution compared to the native image files (see Methods). Mag bar  = 100 µm.