THE INFLUENCE OF TREATMENT CONDITIONS ON THE SELECTIVE MUTAGENIC ACTION OF DIEPOXYBUTANE IN NEUROSPORA

Abstract

The causes of mutagen specificity in a di-auxotrophic strain of Neurospora were studied. In this strain, diepoxybutane (DEB) preferentially produced adenine reversions, while UV light produced fewer adenine than inositol reversions. The selectivity of DEB in this system could be strikingly reduced when treatment was given to a growing culture of in vitro to conidia. DEB in the growth medium may act through an intermediate compound which is much less specific than the original one. This would rule out the possibility that the low selectivity of DEB in the growth medium is causally related to the similarly low selectivity of very low doses of conidial treatment That 2 different modifications of the treatment can result in the same reduction of selectivity indicates that mutagen specificity is not only due to specific chemical reactions between mutagen and DNA.