Rapid identification of non-allelic nystatin resistance mutations in Dictyostelium discoideum

Abstract

Spontaneous nystatin resistance mutations in Dictyostelium discoideum fall into three complementation groups; nys A. nys B and nys C. We demonstrate three methods for rapidly distinguishing mutations in the three complementation groups. In the first method nys B and nys C mutations are identified by their sensitivity to the sterol biosynthesis inhibitors azasterol A25822B and fenarimol respectively. The second method exploits the differential sensitivities of the nys mutations to the polyene antibiotic pimaricin. In the last method we show that nys C and non-nys C mutants can be distinguished on the basis of the Lieberman-Burchard color reaction for sterols.