Dispensable and Indispensable Genes in Neurospora

Science  17 Apr 1964:
Vol. 144, Issue 3616, pp. 307-308
DOI: 10.1126/science.144.3616.307


Twenty-four recessive lethal mutations were detected in a heterokaryon by the method of Atwood and Mukai. All controlled indispensable functions. Genetic analysis revealed that six of these failed to transmit the defect to their progeny. These mutants are believed to be semilethal genetic changes which express a lethal phenotype only in certain genetic backgrounds.