We have outlined a procedure that allows the large-scale screening of mutagenized Neurospora crassa populations for invertaseless mutants. We have isolated and characterized three mutations, inv(DBL1), inv(DBL9) and inv(DBL14), which have been mapped at or near the invertase structural gene. One of these, inv(DBL1), is particularly interesting. Our experiments indicate that the reduced level of...

N earlier studies with Neurospora, it was believed that with biochemical I mutants the heterocaryon test was a satisfactory test for allelism, based on the expectation that only heterocaryons between nonallelic mutants should be capable of growth on nonsupplemented media (BEADLE and COONRADT 1944). However, experiments by MITCHELL and MITCHELL (1956) suggested that a positive heterocaryon test ...

We have isolated and sequenced a tRNAPhe gene from Neurospora crassa. Hybridization analyses suggest that trnaPhe is the only tRNA encoded on the cloned 5 kb DNA fragment. The tRNAPhe gene contains an intervening sequence 16 nucleotides in length located one nucleotide 3' to the anticodon position. The tRNAPhe coding region of Neurospora and yeast are 91% conserved, whereas their intervening se...

Cytosine methylation of DNA is an important epigenetic gene silencing mechanism in plants, fungi, and animals. In the filamentous fungus Neurospora crassa, nearly all known DNA methylations occur in transposon relics and repetitive sequences, and DNA methylation does not depend on the canonical RNAi pathway. disiRNAs are Dicer-independent small non-coding RNAs that arise from gene-rich part of ...

The genetics and biochemistry of tryptophan metabolism in the bread mold, Neurospora cras&a, have received considerable experimental attention during the past 20 years. By now, an impressive body of information has accumulated to the extent that the intimate details of the biosynthesise and degradation'-' of tryptophan in Neurospora are well known and also to the extent that the genetics of thi...

It is now believed that the amino groups of isoleucine and valine are accepted by their respective carbon chains during biosynthesis via a transamination. Most of the evidence for this hypothesis has been derived from experiments on isoleucineless and valineless mutants of Escherichia coli and Neurospora crassu (l-4). It is not positively established whether this transamination step can be medi...

Blue light-induced absorbance changes were measured from differentially centrifuged membrane fractions from dark-grown coleoptiles of Zea mays L., and mycelia from an albino mutant of Neurospora crassa. Actinic irradiation caused changes in absorbance consistent with a flavinmediated reduction of a b-type cytochrome. Both corn and Neurospora showed similar light-minus-dark difference spectra, d...

Neurospora tetrasperma is a pseudohomothallic filamentous ascomycete that has evolved from heterothallic ancestors. Throughout its life cycle, it is predominantly heterokaryotic for mating type, and thereby self-fertile. However, studies of N. tetrasperma have revealed the occasional production of self-sterile asexual and sexual spores of a single-mating type, indicating that it can be function...

In Neurospora crassa, the interactions between products of the frequency (frq), frequency-interacting RNA helicase (frh), white collar-1 (wc-1), and white collar-2 (wc-2) genes establish a molecular circadian clockwork, called the FRQ-WC-Oscillator (FWO), which is required for the generation of molecular and overt circadian rhythmicity. In strains carrying nonfunctional frq alleles, circadian r...