Table 1.

Social genes in the amoeba D. discoideum

	Sociality	Chimerism	Antagonism	Cheater
Sociality	─	22	507**	9
Chimerism	26	─	44*	2
Antagonism	261	30	─	15
Cheater	13	1	14	─

Sociality genes are effectively expressed in the facultatively expressed social cycle, as measured by an index of social expression (see Methods). Chimerism genes are those differentially expressed in chimeras compared with clonal development, specifically at the slug stage. Antagonism is a group formed by previously identified genes differentially expressed in prespore and prestalk cells^7,23. Cheater genes were previously characterized from mutagenesis screenings to identify mutants with defective behavior²⁸. Significance for the overlaps between each pair of gene categories was obtained by chi-square tests. Cell entries give the observed (upper diagonal) and expected (lower diagonal) values, with significant deviations from expected (FDR-corrected p < 0.05) being indicated by bold observed values. * indicates FDR-corrected p < 0.05, whereas ** indicates p < 10⁻⁷⁰