title: Isolation and characterization of a methylammonium resistant mutant of Neurospora crassa.
abstract: A mutant of Neurospora crassa has been isolated which is resistant to methylammonium, a structural analog of ammonium. In contrast to wild type, this mutant, mea-1, has derepressed nitrate reductase and nitrite reductase activities in the presence of ammonium. However, glutamine still represses these nitrate assimilation enzymes in mea-1. The nit-2 mutant was epistatic to mea-1 since the mea-1; nit-2 double mutant has the nit-2 mutant phenotype. In addition, mea-1; nit-2 double mutants cannot utilize ammonium as a nitrogen source. We suggest therefore that nit-2 and mea-1 loci play a role in ammonia/methylamine uptake.
authors.affiliation: Department of Biology, Gilmer Hall, University of Virginia, 22901, Charlottesville, Virginia, USA.
authors.forename: N S
authors.initials: NS
authors.lastname: Dunn-Coleman
authors.forename: M D
authors.initials: MD
authors.lastname: Nassiff
authors.forename: R H
authors.initials: RH
authors.lastname: Garrett