scholarly journals A PARACRYSTALLINE INCLUSION IN NEUROSPORA CRASSA

1971 ◽  
Vol 51 (1) ◽  
pp. 249-264 ◽  
Author(s):  
David D. Wood ◽  
David J. L. Luck

A paracrystal indistinguishable from the one which occurs in the mitochondrial mutant abnormal-1 can be induced in wild-type Neurospora crassa after growth in either ethidium or euflavine. This paracrystal has been isolated and partially characterized. It appears to be composed of a single polypeptide (mol wt 68,000) which can be reversibly crystallized and dissociated by changes in the pH and ionic strength. When aggregated, the polypeptide forms oligomers which are arranged end-to-end into fibers. During the characterization of the polypeptide, it was found that the polypeptide's electrophoretic and immunological properties could be used as assays. Using these methods it was found that the polypeptide normally accumulates in a soluble form in the cytoplasm of wild-type Neurospora at the end of the log-phase of growth.

1985 ◽  
Vol 232 (2) ◽  
pp. 425-430 ◽  
Author(s):  
M T Téllez-Iñón ◽  
R M Ulloa ◽  
G C Glikin ◽  
H N Torres

Activation of cyclic AMP phosphodiesterase I by brain or Neurospora calmodulin was studied. The stimulation required micromolar concentrations of Ca2+, and it was observed at cyclic AMP concentrations between 0.1 and 500 microM. Activation was blocked by EDTA and some neuroleptic drugs such as chlorpromazine and fluphenazine. These drugs inhibit the elongation of N. crassa wild-type aerial hyphae. These results reinforce the evidence towards the recognition of Ca2+-calmodulin as one of the systems controlling cyclic nucleotide concentrations in Neurospora.


Genetics ◽  
1973 ◽  
Vol 75 (1) ◽  
pp. 61-73
Author(s):  
John F Lehman ◽  
Mary K Gleason ◽  
Sandra K Ahlgren ◽  
Robert L Metzenberg

ABSTRACT A mutant of Neurospora crassa, called UW-6, differs from wild type in being partially constitutive for synthesis of a species of alkaline phosphatase, and also for a species of phosphate permease that has a high affinity for phosphate at high pH. UW-6 is possibly allelic with a mutant called nuc-2 that was previously isolated by Ishikawa. nuc-2 has the converse phenotype, in that it cannot be derepressed for either of these two activities. UW-6 is co-dominant with its wild-type allele in heterokaryons and in partial diploids. An unlinked mutant, nuc-1, is like nuc-2 in that it fails to make the alkaline phosphatase or the permease referred to above. nuc-1 is epistatic to UW-6 in the double mutant. The control of phosphorus metabolism is discussed, and is compared with some other control systems in filamentous fungi.


Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 1069-1079 ◽  
Author(s):  
Adlane V-B Ferreira ◽  
Zhiqiang An ◽  
Robert L Metzenberg ◽  
N Louise Glass

AbstractThe mating-type locus of Neurospora crassa regulates mating identity and entry into the sexual cycle. The mat A idiomorph encodes three genes, mat A-1, mat A-2, and mat A-3. Mutations in mat A-1 result in strains that have lost mating identity and vegetative incompatibility with mat a strains. A strain containing mutations in both mat A-2 and mat A-3 is able to mate, but forms few ascospores. In this study, we describe the isolation and characterization of a mutant deleted for mat (ΔmatA), as well as mutants in either mat A-2 or mat A-3. The ΔmatA strain is morphologically wild type during vegetative growth, but it is sterile and heterokaryon compatible with both mat A and mat a strains. The mat A-2 and mat A-3 mutants are also normal during vegetative growth, mate as a mat A strain, and produce abundant biparental asci in crosses with mat a, and are thus indistinguishable from a wild-type mat A strain. These data and the fact that the mat A-2 mat A-3 double mutant makes few asci with ascospores indicate that MAT A-2 and MAT A-3 are redundant and may function in the same pathway. Analysis of the expression of two genes (sdv-1 and sdv-4) in the various mat mutants suggests that the mat A polypeptides function in concert to regulate the expression of some sexual development genes.


Genetics ◽  
1984 ◽  
Vol 106 (4) ◽  
pp. 591-599
Author(s):  
Deborah B Lee ◽  
Stephen J Free

ABSTRACT 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 invertase activity in the inv(DBL1)-containing cell can be explained as the result of a reduced number of normal enzyme molecules. We also show that wild-type Neurospora is able to respond rapidly to a change of medium and can dramatically increase its production of invertase within 20 min after a transfer to a carbon-free medium.


1984 ◽  
Vol 221 (2) ◽  
pp. 541-543 ◽  
Author(s):  
J A Reig ◽  
M T Téllez-Iñón ◽  
M M Flawiá ◽  
H N Torres

The soluble form of adenylate cyclase was extracted and purified from wild-type Neurospora crassa mycelia. Brain or N. crassa calmodulin significantly enhanced this enzyme activity in assay mixtures containing Mg2+-ATP as substrate. EGTA reverses this calmodulin activation.


1977 ◽  
Vol 29 (1) ◽  
pp. 9-19 ◽  
Author(s):  
N. C. Mishra

SUMMARYInositol independent (inl+) strains were obtained either as transformants following treatment of the inositol requiring (inl) strains ofNeurospora crassawith the wild-type DNA or as revertants without any DNA treatment. A significant number of the inositol-independent transformants were also found to have acquired additional mutations called osmotics (os) which made them unable to grow on 1 m-NaCl medium. None of the inositol-independent revertants were found to possess such osmotic mutations and their growth remained unaffected by the presence of NaCl. Many of the osmotic mutants described here were found to be new alleles of the previously knownos–1mutation on the linkage group I ofNeurospora crassa. The remainder were found to map at two new genetic loci designated asos-6andos-7; these loci were found to be closely linked toos–1. Among the new osmotic mutants onlyos-1andos-6mutants showed intragenic complementation. The mechanism of DNA-induced mutation during transformation is discussed.


Genetics ◽  
1983 ◽  
Vol 104 (1) ◽  
pp. 11-21
Author(s):  
John Paietta ◽  
Malcolm L Sargent

ABSTRACT As part of a genetic analysis of blue light photoreception in Neurospora, three mutants were isolated that do not exhibit photosuppression of circadian conidiation, i.e., they show periodic conidiation in constant light. The mutations have been given the designations lis-1, lis-2 and lis-3 ("light insensitive"). The three mutations segregate as single nuclear genes, are nonallelic and are recessive to wild type in heterokaryon tests. The linkage groups of the mutations are as follows: lis-1, I; lis-2, VI; and lis-3, V. The light -insensitive phenotype of the mutants is restricted to the photosuppression response; other responses such as photoinduced phase shifting of the conidiation rhythm and photoinduced carotenogenesis are not altered. The physiological or biochemical defects of the mutants have not been established, but they are not similar to previous reported cases (i.e., rib and poky) in which a reduction in light sensitivity has been observed.


Sign in / Sign up

Export Citation Format

Share Document