QuickTime Video

Movie 1

(Fig. 1) Wave propagation in a slug of Dictyostelium discoideum.
Upper sequence: Fluorescence image showing movement of GFP labelled cells inside the slug.
Lower sequence: Subtracted brightfield images reveal propagation of optical density waves from the front to the back of the slug.
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QuickTime Video

Movie 2

(Fig. 2) Correlation of wave propagation and cell movement in streamer NP377 slugs.
Upper sequence: Brightfield image of slug. The wave intensity for cell1 was measured in the red window. Waves propagate from the front to the back of the slug.
Middle sequence: Fluorescence image with blue window indicating the position of cell 1. The cells move periodically.
Lower sequence: Graph showing correlation between wave intensity and cell velocity during the course of the sequence.

QuickTime Video

Movie 3

(Fig. 3) Wave propagation in isolated slug tips.
Brightfield sequence of an isolated tip from a slug of strain NP377. The tip continues to move. Waves are still present and initiated in the anterior part of the tip.

QuickTime Video

Movie 4

(Fig. 4) Effect of tip removal on cell movement in slugs.
Initially waves are present and cells exhibit periodic cell movement. After tip removal, no further waves appear and the coordinated cell movement is lost. Cells slow down and the slug rounds up.
Upper sequence: Brightfield image of a NP377 slug showing wave propagation.
Lower sequence: Fluorescence image showing cell movement

QuickTime Video

Movie 5A

(Fig. 5) cAMP microinjection and wave propagation in slugs. A microelectrode containing 0.01 M cAMP is injected into the slug and a pulse of cAMP is given once as indicated. After injection the wave fronts disappear and the slug slows down temporarily.

QuickTime Video

Movie 5B

(Fig. 5) Effect of cAMP on cell movement in slugs.
Initially cAMP (concentration in microelectrode = 0.01 M) is injected periodically (3 minute intervals) into the anterior prespore region of a Neutral Red stained slug. The slug tip continues to move, while posterior cells are largely immobilised. The microelectrode is finally removed. The stained anterior-like cells sort out and a new tip is formed at the former position of the electrode.

QuickTime Video

Movie 6

(Fig. 6) Optical density waves in strain NP377 during different stages of development.
Optical density waves are present throughout Dictyostelium development.
Upper sequence: Darkfield waves during early aggregation.
Middle sequence: Optical density waves in a mound with streams.
Lower sequence: Optical density waves in slugs.