The Isolation of Ultraviolet Sensitive Mutants from Aspergillus rugulosus

Abstract
Four ultraviolet light-sensitive mutants were isolated in Aspergillus rugulosus. Ultraviolet light survival curves for these mutants were characterized by the absence or reduction of the shoulder observed in the curves of nonsensitive strains. The absence of a shoulder may reflect the lack of one or more enzymes essential for the repair of UV-damaged DNA. All mutants were cross sensitive to inactivation by nitrous acid. A genetic analysis of one of these mutants indicated that UV sensitivity is controlled by a single nuclear gene. It is also possible, however, that UV sensitivity may be affected by factors having nothing to do with DNA repair. Differences in conidial pigmentation were shown to influence sensitivity to UV light.