Phenotypic analyses of the viable L11 mutants. (A) 10-fold dilutions of indicated yeast strains were spotted onto SD–Trp media and incubated at temperatures indicated, or (B) on SD–Trp media containing paromomycin, anisomycin or sparsomycin at the indicated concentration and grown at 30°C. (C) Killer virus assays. Wild-type (WT) Killer⁺ cells are identified by a zone of growth inhibition. 51-4A, 54-7A and F57A mutants lack this halo, indicating the Killer⁻ phenotype.