A way of following individual cells in the migrating slugs of Dictyostelium discoideum
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Contributed by J. T. Bonner
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Figure 1A large (A) and a small (B) 2-D slug photographed from a TV monitor showing a videotape. The large slug is 470 μm long and contains ≈2,020 cells; the small one is 80 μm long and has ≈110 cells.
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Figure 2The movement of individual cells in a migrating 2-D slug. (A) A photograph of an individual frame (the slug is 175 μm long and is made up of ≈226 cells). (B) The tracings of selected cells. 50 frames from a video of the slug, spanning 6 min in real time, were caught on a computer and played repeatedly so a few individual cells could be followed by tracing them on the screen. Note the difference in the speed and the direction between the anterior and posterior amoebae. [This was done on a Silicon Graphics (Mountain View, CA) O2 workstation and a Silicon Graphics media recorder utility to capture a sequence of the individual video frames.]
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Figure 3A computer image of a single video frame of a 2-D slug in the process of splitting in two. The arrows represent 6 min of cell movement, using the same methods described in the caption of Fig. 2. Note the two active regions of cell motion that are moving away from one another. (The cell mass is 139 μm long and is made up of ≈330 amoebae.)
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Figure 4A log-log graph showing that the number of prestalk cells is proportional to the number of spore cells in slugs of different sizes. •, Normal slugs taken from an early study (23). They were stained with a vital dye to distinguish the two zones and their respective volumes estimated and converted to cell numbers. ○, 2-D slugs of this study.
- Copyright © 1998, The National Academy of Sciences
