[Genetic control of pathways of pyrimidine metabolism in Aspergillus nidulans. 1. Isolation and genetic analysis of 6-azauracil resistant mutants].

147 mutants exhibiting the resistance to toxic effect of 6 azauracil have been isolated by nitrosoguanidine treatment from the wild strain of Aspergillus nidulans. This mutants have been divided into 11 phenotypic groups according to its cross-resistance to 5-fluoroderivatives of uracil, uridine and deoxyuridine. The genetic analysis has shown that all mutations of resistance are of nuclear origin and dominant nature, and they are distributed on six loci of the chromosome VIII.