The Effect of Nitrogen Mustard Pretreatment on the Ultra-Violet-Induced Morphological and Biochemical Mutation Rate

Abstract

Pretreatment of the microconidia of Neurospora crassa with a relatively non-mutagenic concn. of nitrogen mustard alters the stability of the genes in such a manner as to increase significantly the effectiveness of u.-v. in inducing morphological and biochemical mutations. It is suggested that the increased frequency of mutations results from an increased frequency of intra-genic rather than extra-genic (chromosomal) alterations.