Deletion mapping of theniiAniaD gene region ofAspergillus nidulans

Abstract

SUMMARYThe genetic fine-structure of theniiAniaD gene region ofAspergillus nidulanshas been studied using deletion mapping. Deletions were identified asniiAniaD double mutants and comprised 1% of spontaneous chlorate-resistant mutants. All such double mutants were shown to involve deletions and their frequency was not increased by mutagenic treatment with eitherN-methyl-N′-nitro-N-nitrosoguanidine or with ultraviolet light. Deletion maps of theniaD andniiA genes have been constructed. A further class of mutation was also mapped using the deletions. Thesecrnmutations, which affect a gene whose function is as yet unknown, map on the centromere proximal side ofniiA. This analysis of a eukaryote gene cluster will provide a framework upon which to base studies of the regulation of the nitrate assimilation pathway.