The chtB mutant cheats on AX4. When mixed with the parental strain AX4 [act15/GFP], chtB differentiates 59.9±3.3% (n=22) of the total spores. Control AX4 cells mixed with AX4 [act15/GFP] cells differentiate 50.1±1.0% (n=27) of the total number of spores. The chtB strain differentiates a significantly higher number of spores than the parental strain (Two tailed t-test, p<.0001. Bars represent standard errors).