Table 1.

Periods of oscillation of [cAMP]_i and cell velocity at three developmental stages

	Early aggregation	Loose mound	Tight mound	Slug
Periods of cell velocity (min)	5.58 ± 0.47	2.48 ± 0.22	4.78 ± 0.31	5.32 ± 1.09
Periods of [cAMP]i oscillation (min)	5.62 ± 0.36	2.47 ± 0.28	4.70 ± 0.56	ND
Phase difference between cell velocity and [cAMP]i oscillation (min)	0.29 ± 0.29	1.26 ± 0.26	0.15 ± 0.12	ND

Mean values ± SD are shown. Sample numbers are as follows: 100 cells in 6 aggregation centers (early aggregation), 45 cells in 7 mounds (loose mound stage), 47 cells in 5 mounds (tight mound stage), and 20 cells in 11 slugs (slug stage). The periods of [cAMP]_i oscillations and cell velocities in the loose mound stage are significantly shorter than those in the early aggregation and the tight mound stages (P < 10^–5: Student’s two-tailed t-test)

ND no detection of periodicity