Molecular and classical genetic analyses of his-3 mutants of Neurospora crassa. I. Tests for allelic complementation and specific revertibility.
A collection of 81 his-3 mutants of Neurospora crassa was analyzed in assays for allelic complementation and specific revertibility. In these studies, the linearity of the complementation map of the his-3 cistron (Webber, 1965) was confirmed and mutants were classified as complementing with non-polarized or polarized complementation patterns, or non-complementing. In the assays for spontaneous or induced revertibility, 89% (71/80) of the mutants reverted either spontaneously or after treatment with the chemical mutagens N-methyl-N'-nitro-N-nitrosoguanidine, ethyl methanesulfonate, 2-methoxy-6-chloro-9-(3-[ethyl-2-chloroethyl]aminopropylamino) acridine dihydrochloride, nitrous acid or hydroxylamine. The frequency of revertible mutants among the non-polarized complementing mutants was 96% (45/47), and 79% (15/19) for the polarized complementing and 79% (11/14) for the non-complementing mutants. The results of these classical genetic assays for allelic complementation and specific revertibility suggest a correlation between complementation pattern and presumptive genetic alterations at the molecular level among his-3 mutants similar to that found with ad-3B mutants induced by nitrous acid (Malling and de Serres, 1967), ethyl methanesulfonate (Malling and de Serres, 1968), or ultraviolet (Kilbey et al., 1971).
Overton
L K
LK
Center for Life Sciences and Toxicology, Research Triangle Institute, Research Triangle Park, NC 27709-2194.
Dubins
J S
JS
de Serres
F J
FJ
D000483:Alleles; D005816:Genetic Complementation Test; D009153:Mutagens / Q000494:pharmacology*; D009154:Mutation; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D014466:Ultraviolet Rays
D009153:Mutagens