Bioassay for the Isolation of Dictyostelium discoideum Mutants Deficient in Extracellular Accumulation of Cyclic Adenosine 3′5′-Monophosphate

摘要

The growth response to external cyclic adenosine 3′,5′-monophosphate of a strain of Escherichia coli deleted for adenyl cyclase was utilized to screen for mutants of Dictyostelium discoideum unable to accumulate this chemical extracellularly. The threshold amount of cyclic adenosine 3′,5′-monophosphate able to induce growth of this bacterium was 3 to 4 μg/ml at 37 C and approximately 25 μg/ml at 27 C. Conditions are described that permit the detection of as low as 2 μg of this chemical at either temperature.