Abstract: | Four omega-aminocarboxylic acids - epsilon-aminocaproic acid (EACA), trans-4-aminomethylcyclohexane-1-carboxylic acid (t-AMCHA), p-aminomethylbenzoic acid (PAMBA) and omega-aminocaprylic acid (OACA) -- prevented fruiting body formation of the cellular slime mould Dictyostelium discoideum. At concentrations of 40 mM, 75 mM, 10 mM and 5 mM, respectively, they allowed aggregation but prevented all further development at 24 degrees C. At lower concentrations, EACA allowed fruiting body formation but with a reduced number of spores per fruiting body. Only t-AMCHA had a significant inhibitory effect on the growth of myxamoebae. EACA affected development only if it was present between 8 and 16 h after the cells were deposited on the filters. Its effect was enhanced by high salt concentrations and by higher temperature, and was also dependent on the manner in which the cells were grown. Only strains capable of axenic growth displayed this sensitivity to EACA, although strains carrying only one of the genetic markers for axenic growth (axe A) were partially sensitive. |