[Metabolic pathways of exogenous pyrimidines in Aspergillus nidulans].

Studies on the susceptibility of the wild-type strain of Aspergillus nidulans to 6-azauracil suggest that it synthesizes pyrimidines using a by-pass pathway which is induced with 6-azauracil. The effect of a series of pyrimidines on the toxic action of 5-fluorouracil, 5-fluorouidine and 5-fluorodeoxyuridine has been investigated. As the result of these studies, a scheme is proposed for the metabolism of some pyrimidine bases and nucleosides in Aso. nidulans.