Table 1.

Efficiency of spore formation by T10 cells co-cultured with AX2 cells on soil

T10 cells at beginning of experiment, %	Number of colonies in colony blots		T10 spores in mixed fruiting bodies, %
	AX2	T10
50	16	3	15.8
50	13	6	31.6
50	18	2	10.0
50	62	11	15.0
50	46	11	19.3
50	67	17	20.2
Totals	222	50*	18.4

AX2 and T10 at beginning of starvation were mixed in a proportion of 1:1 and were incubated for development on soil plate B. After fruiting body formation, spores were collected randomly and were plated on E. Coli B/2 at a density of 20 spores per agar plate. When colonies were ≈1 cm in diameter, they were blotted onto nitrocellulose, and the blots were incubated with mAb 448, which recognizes a peptide epitope of csA. The bound antibody was detected by chemiluminescence, and the colonies also were stained with red Ponceau (16). The number of colonies positive (AX2) or negative (T10) for csA in six experiments was counted, and the percentage of T10 spores in mixed fruiting bodies was extrapolated. 

^*P < 0.001 (χ² test), relative to total number of colonies.