TitleAbstractYear(sorted ascending)
molecular alteration in a neurospora crassa morphological mutant and its phenocopy.a procedure using ion exchange chromatography has been developed to detect alterations in a polysaccharide produced by neurospora crassa. the polysaccharide, isolated from medium that has supported the growth of a culture, is highly responsive to the 3-methyl-2-benzothiazolinone hydrazone assay, indicating a high hexosamine content. the substance elaborated by wild-type n. crassa can be fractionated into two components that appear by rechromatography to be closely related. when isolated from mut ...1978148650
ultrastructural study of microcyclic macroconidiation in neurospora crassa.heat-shock of macroconidia of neurospora crassa at 46 degrees c followed by shift-down to 25 degrees c determines premature conidiogenesis. the nuclei and cytoplasmof heat-treated, swollen conidia contain spots of a dense material especially concentrated around the nucleolus in short time treated ones. in the first proconidium apically budding on the enlarged tip of the premature conidiophore, small vesicles are later seen lining the initially simple septum separating the proconidial units into ...1978148251
cyanide- and hydroxamate-resistant respiration in neurospora crassa.strain inl-89601 of neurospora crassa respires exclusively by means of the mitochondrial cytochrome chain. the respiration of this strain is entirely inhibited by cyanide or antimycin a, the classical inhibitors of cytochrome chain respiration. when this strain was grown in the presence of chloramphenicol, however, two additional terminal oxidases were detected. one of these oxidases is inhibited by substituted hydroxamic acids and has been described previously. the second oxidase was not inhibi ...1978147864
biosynthesis of glycogen in neurospora crassa. purification and properties of the udpglucose:glycogen 4-alpha-glucosyltransferase.the neurospora crassa glycogen synthase (udpglucose:glycogen 4-alpha-glucosyltransferase, ec was purified to electrophoretic homogeneity by a procedure involving ultracentrifugation, deae-cellulose column chromatography, (nh4)2so4 fractionation and 3-aminopropyl-sepharose column chromatography. the final purified enzyme preparation was almost entirely dependent on glucose-6-p and had a specific activity of 6.9 units per mg of protein. the subunit molecular weight of the glycogen syntha ...197823841
mutations of the a mating-type gene in neurospora neurospora, the mating-type locus controls both mating ( a + a is fertile) and heterokaryosis (a + a is incompatible). the two alleles appear stable: no novel fertility reactions have ever been reported, and attempts to separate fertility and heterokaryon incompatibility functions by recombination have been unsuccessful. in the present approach the locus was studied through a mutational analysis of heterokaryon incompatibility function. a selection system was used that detects vigorous (a + a ...197817248797
genetic and physiological characteristics of a slow-growing circadian clock mutant of neurospora crassa.a circadian clock mutant of neurospora crassa with a period length of about 25.8 hours (4 hr longer than wild type) has been isolated after mutagenesis of the band strain. this mutant, called frq-5, segregates as a single nuclear gene, maps near the centromere on linkage group iii, and is unlinked to four previously described clock mutants clustered on linkage group vii r (feldman and hoyle 1973, 1976). frq-5 differs from the other clock mutants in at least two other respects: (1) it is recessiv ...1978147796
the subunit structure of the arom multienzyme complex of neurospora crassa. evidence from peptide 'maps' for the identity of the subunits.evidence was obtained, from polyacrylamide-gel electrophoresis in the presence of urea and from peptide 'mapping' of specifically labelled cysteine-and methionine-containing peptides, that the two subunits of the arom multienzyme complex of neurospora crassa are chemically very similar and possibly identical.1978147081
structural features of normal and complemented forms of the neurospora isopropylmalate isomerase.the isopropylmalate isomerase (ec of neurospora crassa is a globular protein consisting of a single polypeptide chain with a molecular weight of about 90,000. the isomerase cannot easily be freed of a contaminating protease which cleaves the enzyme into two major fragments, one of approximately 56,000 and the other 37,000 daltons. this suggests that the folded polypeptide chain may contain some hinge point or loop exposed on the surface which makes it susceptible to proteolytic attack. ...1978146703
regulation of isopropylmalate isomerase synthesis in neurospora crassa.the capacity to synthetize isopropylmalate isomerase (ec by neurospora crassa increased during induction in the presence of cycloheximide but was inhibited by proflavine and other inhibitors of rna synthesis. turnover of the enzyme once formed appeared negligible, but the message (measured as enzyme-forming capacity) had a half-life of 4 to 8 min. a comparison of the kinetics of induction in the wild type and a newly isolated alpha-isopropylmalate-permeable strain suggested strongly th ...1978146702
induction and repression of nitrate reductase in neurospora crassa.synthesis of wild-type neurospora crassa assimilatory nitrate reductase is induced in the presence of nitrate ions and repressed in the presence of ammonium ions. effects of several neurospora mutations on the regulation of this enzyme are shown: (i) the mutants, nit-1 and nit-3, involving separate lesions, lack reduced nicotinamide adenine dinucleotide (nadph)-nitrate reductase activity and at least one of three other activities associated with the wild-type enzyme. the two mutants do not requi ...1978146700
mitochondrial adenosine triphosphatase of wild-type and poky neurospora crassa.we have compared the adenosine triphosphatase (atpase) activity of mitochondria prepared from wild-type neurospora crassa and from poky, a maternally inherited mutant known to possess defective mitochondrial ribosomes and reduced amounts of cytochromes aa3 and b. poky contains two distinct forms of mitochondrial atpase. the first is normal in its km for atp, specificity for nucleotides and divalent cations, ph optimum, cold stability, and sensitivity to inhibitors (oligomycin, n,n-dicyclohexyl c ...197824038
isolation and characterization of perithecial development mutants in neurospora.the isolation and characterization of mutants that block perithecial development in neurospora crassa are described. several classes of mutants have been isolated after uv mutagenesis, and those that block perithecial development when used as the female (protoperithecial) component of a cross have been further characterized. these mutants fall into 29 complementation groups. twelve of the 33 mutants block development at the protoperithecial stage; no other clustering of block points is observed. ...197817248793
nuclear suppressors of the [poky] cytoplasmic mutant in neurospora crassa. iii. effects on other cytoplasmic mutants and on mitochondrial ribosome assembly in [poky].we have previously isolated six non-allelic, nuclear mutations (sui loci) that partially suppress the growth, respiratory and cytochrome abnormalities of the extranuclear [poky] mutant. a comparison of the mitochondrial ribosome profiles of suppressed and unsuppressed [poky] strains revealed that five of the six suppressors alleviate at least partially the deficiency of mitochondrial small ribosomal subunits that is associated with the [poky] genotype. six independently isolated group 1 extranuc ...1978149910
purification of cytochrome oxidase from neurospora crassa and other sources. 1978213692
disappearance of the cyanide-insensitive pathway of oxidation in mitochondria of mi-1 mutant of neurospora crassa in vitro.oxidation of exogenous nadh in mitochondria isolated from wild type and mi-1 mutant of neurospora crassa decreases rapidly in vitro. in mi-1 mutant mitochondria the inactivation concerns the alternate pathway of oxidation whereas in the wild type it involves an unknown component of the respiratory chain. the activity of the primary nadh dehydrogenase is constant within the time of the experiments (2-4 h). nadh oxidase is not inactivated if oxygen is removed from the incubation medium by nitrogen ...1978208334
factors influencing the uptake of dna by neurospora crassa.under optimal conditions intact neurospora crassa cells incorporated nearly the same amount of 3h-labelled dna as that of the endogenous dna content of cells. after 18 h of incorporation more than 80 per cent of the radioactivity was retained in the cells. a maximum uptake of exogenous dna occurred at 28 degrees c, ph 6.35, in the presence of 100 mm calcium when the concentration of donor dna was 150 micrograms/ml. denatured dna was incorporated at a higher rate than native dna. the present find ...197839418
kinetic properties of pyruvate kinase of neurospora crassa at physiological ph.the kinetic properties of pyruvate kinase (ec extracted from the mycelia of neurospora crassa were examined at physiological ph to determine the role of the enzyme in the regulation of glycolysis. the velocity curve with the substrates, phosphoenolpyruvate and adenosine diphosphate, are hyperbolic. the effect of magnesium, potassium, or calcium on the enzyme is influenced by the ph but not to the extent that would change their role as cofactor or inhibitor. adenosine triphosphate and c ...197827701
fungal transformation of naphthalene.eighty-six species of fungi belonging to sixty-four genera were examined for their ability to metabolize naphthalene. analysis by thin-layer and high pressure liquid chromatography revealed that naphthalene metabolism occurred in forty-seven species belonging to thirty-four genera from the major fungal taxa. all organisms tested from the order mucorales oxidized naphthalene with species of cunninghamella, syncephalastrum and mucor showing the greatest activity. significant metabolism was also ob ...1978678019
isolation and characterization of isocitrate lyase from a thermophilic bacillus sp.isocitrate lyase was isolated in homogeneous state from a thermophilic bacillus. the enzyme has a mol.wt. of 180000 and a pi of 4.5 and contains threonine as the n-terminal residue. it resembles in size the cognate enzyme from the mesophilic bacterium pseudomonas indigofera, but is smaller than the enzyme from the eukaryotic fungus neurospora crassa. all three lyases are tetramers and similar in amino acid composition, but the thermophile enzyme is distinctive from its mesophilic coutnerparts in ...1978687365
isolation of neurospora crassa-bovine l-glutamate dehydrogenase hybrids [proceedings]. 1978154423
organization of the ribosomal ribonucleic acid gene cluster of neurospora crassa by means of restriction endonucleases and cloning in bacteriophage lambda [proceedings]. 1978154424
transcription and translation in e. coli of hybrid plasmids containing the catabolic dehydroquinase gene from neurospora crassa.two hybrid plasmids which carry the gene for neurospora crassa catabolic dehydroquinase (c-dhqase) and complement an arod6 (dehydroquinase-deficient) auxotroph of escherichia coli have been analyzed. one of these contains a 2.9 kilobase (kb) fragment cloned in the hindiii site of plasmid pbr322 (pvk57) and the other contains a 6.8 kb fragment cloned in the psti site (pvk88). restriction enzyme mapping of these plasmids has demonstrated that the 2.9 kb fragment is totally contained within the 6.8 ...1978154430
structural analysis of viral replicative intermediates isolated from adenovirus type 2-infected hela cell nuclei.deoxyribonucleoprotein complexes released 17 h postinfection from adenovirus type 1 (ad2)-infected hela cell nuclei were shown by electron microscopy to contain filaments much thicker (about 200 a [20 nm]) than double-stranded dna (about 20 a [2 nm]). the complexes were partially purified through a linear sucrose gradient, concentrated, and further purified in a metrizamide gradient. the major protein present in the complexes was identified as the 72,000-dalton (72k), adenovirus-coded single-str ...1978207893
isolation of precursors of cytochrome oxidase from neurospora crassa: application of subunit-specific antibodies and protein a from staphylococcus aureus.a novel immunological procedure has been applied for the isolation of precursors of cytochrome oxidase. it involves antibodies to individual subunits of the oxidase and protein a from staphylococcus aureus linked to a sepharose support. unassembled (free) 'subunits' as well as a labile complex containing five polypeptide components of the oxidase were isolated from mitochondrial extracts by this technique. the procedure is superior to the previously used double-immuno-precipitation method, becau ...1978213273
use of the spot, plate and suspension test systems for the detection of the mutagenicity of environmental agents and chemical carcinogens in neurospora crassa.n23 and n24, selected from hundreds of ad-3 mutants, have been used as testers for the spot, plate and suspension tests in neurospora crassa. these two testers are highly sensitive to mutagens and are revertible by a specific group of chemicals. n23 can be reverted from an adenine-dependence to adenine-independence by agents which cause base-pair substitutions whereas n24 can be reverted by frameshift mutagens. studies described here show that spot, plate and suspension tests using testers n23 a ...1978149924
presence of an actin-like protein in mycelium of neurospora crassa.addition of atp, cacl2, and kcl to supernatants prepared from mycelia of snowflake (strain 507), a morphological mutant of neurospora crassa, results in the formation of filaments 70 nm in diameter. the "decorated" appearance of these filaments after incubation with heavy meromyosin from rabbits suggests they are actin-like.1978150412
neurospora crassa mitochondrial transfer mitochondrial trna from neurospora crassa was characterized by base composition analysis, one- and two-dimensional gel electrophoreses and reversed-phase chromatography on rpc5. the guanosine + cytidine content was about 43%, as compared to 60% for cytoplasmic trna. the modified nucleoside content was low and about the same as that of total yeast mitochondrial trna, though the g + c content is very different. we found psi, t, hu, t6a, m1g, m2g, m22g. neither the eukaryotic "y" base, nor th ...1978152130
mutagenicity and mutagenic specificity of metronidazole and niridazole in neurospora crassa.mutagenicity and mutagenic specificity of niridazole and metronidazole, two chemotherapeutic agents used in the treatment of human parasitic diseases, were studied with the ad-3 test system of neurospora crassa. the results show that neither compound is mutagenic in resting conidia. in growing vegetative cells, however, both compounds are mutagenic in n. crassa. genetic analysis of the mutants indicated that niridazole induces predominantly base-pair substitution mutations. none of the niridazol ...1978153406
isolation of a multiprotein complex containing cytochrome b and c1 from neurospora crassa mitochondria by affinity chromatography on immobilized cytochrome c. difference in the binding between ferricytochrome c and ferrocytochrome c to the multiprotein complex.a multiprotein complex which contains in equimolar amounts two cytochromes b (mr each about 27,000), one cytochrome c1 (mr 31,000) and six subunits without known prosthetic groups (mr 8000, 12,000, 14,000, 45,000, 45,000, and 50,000) has been isolated from the mitochondrial membranes of neurospora crassa by affinity chromatography on immobilized cytochrome c. the chromatographic separation was based upon the specific binding of the complex to ferricytochrome c coupled to sepharose and its specif ...197827360
nitrogen source regulates glutamine synthetase mrna levels in neurospora crassa.neurospora crassa glutamine synthetase mrna was measured by its capacity to direct the synthesis of the specific protein in a cell-free system derived from rabbit reticulocytes. n. crassa cultures grown on glutamate as the sole nitrogen source had higher mrna activities than did those grown on glutamine. the differences were about 10-fold when polysomal rna was used for translation and about 5-fold when either total cellular rna or polyadenylic acid-enriched cellular rna was used. these data ind ...197831352
the enzymic synthesis of beta-[32p]udp-n-acetylglucosamine.cells of micrococcus sp. 2102 incorporate inorganic [32p]phosphate from the medium into the sugar-phosphate polymer of the wall. controlled acid hydrolysis of sodium dodecyl sulphate-extracted cells gives n-acetylglucosamine 6-[32p]-phosphate which can be purified by ion-exchange chromatography and incubated with utp in the presence of crude preparations of phosphoacetylglucosamine mutase from neurospora crassa and utp:n-acetylglucosamine 1-phosphate phosphotransferase from bacillus licheniformi ...19789762094
nitrogen-metabolizing enzymes of diplodia maydis, a zea mays l. stalk rot causing fungus.the nitrogen source available to diplodia maydis in vivo is reported to affect the severity of stalk rot in maize. nitrate and (or) ammonium salts were tested for their effect on the type of nitrogen metabolism found in diplodia maydis in vitro. the level of glutamate dehydrogenase remained essentially constant on either nitrogen salt but nitrate reductase was induced by growth on nitrate salts and was not extractable on ammonium salts. properties of nitrate reductase reported here are similar t ...197935273
immunoelectrophoretic determination of nitrate reductase in neurospora crassa. 197940454
the dicyclohexylcarbodiimide-binding protein of the mitochondrial atpase complex from neurospora crassa and saccharomyces cerevisiae. identification and isolation.incubation of mitochondria from neurospora crassa and saccharomyces cerevisiae with the radioactive atpase inhibitor [14c]dicyclohexylcarbodiimide results in the irreversible and rather specific labelling of a low-molecular-weight polypeptide. this dicyclohexylcarbodiimide-binding protein is identical with the smallest subunit (mr 8000) of the mitochondrial atpase complex, and it occurs as oligomer, probably as hexamer, in the enzyme protein. the dicyclohexylcarbodiimide-binding protein is extra ...1979154405
properties of two cyclic nucleotide-deficient mutants of neurospora crassa.studies on the crisp-1 (cr-1), cyclic adenosine 3',5'-monophosphate (camp)-deficient mutants of neurospora crassa were undertaken to characterize the response of these mutants to exogenous cyclic nucleotides and cyclic nucleotide analogs. a growth tube bioassay and a radioimmune assay for cyclic nucleotides yielded the following results. (i) 8-bromo camp and n6-monobutyryl camp but not dibutyryl camp are efficient camp analogs in neurospora, stimulating mycelial elongation of the cr-1 mutants. e ...1979220210
control of cyclic adenosine 3',5'-monophosphate levels by depolarizing agents in has been reported that diverse treatments which depolarize the plasma membrane of neurospora crassa produce rapid increases in cyclic adenosine 3',5'-monophosphate (cyclic amp) levels. in the current study, membrane active antibiotics, which are known or putative depolarizing agents, were found to produce similar cyclic amp increases, not only in n. crassa, but also in the distantly related fungi saccharomyces cerevisiae and mucor racemosus. uncouplers of oxidative phosphorylation, which have ...1979220213
cytochrome c oxidase subunits in nuclear and extranuclear cytochrome-aa3-deficient mutants of neurospora crassa.the mitochondria of cytochrome-aa3-deficient neurospora crassa mutants were screened for the seven polypeptide constiuents of cytochrome c oxidase. the polypeptides of the holoenzyme and the unassembled or partially assembled subunits were detected by sodium dodecyl sulfate/acrylamide gel electrophoresis of immunoprecipitates obtained with antiserum to the holoenzyme as well as to several individual subunits. with respect to the mitochondrially synthesized polypeptides of the oxidase, subunits 1 ...1979223848
is the mitochondrially made subunit 2 of cytochrome oxidase synthesized as a precursor in neurospora crassa? 1979228973
comparison of the genetic activity of 5-nitroimidazole derivatives in escherichia coli, neurospora crassa, saccharomyces cerevisiae and drosophila melanogaster.5-nitroimidazoles, including metronidazole (compound 1) and 3 analogues (compounds 2, 3 and 4) of actual or potential chemotherapeutic use were assayed for genetic activity in test systems detecting forward and back mutations in escherichia coli k-12/343/113, forward mutations in neurospora crassa heterokaryon 12, mitotic gene conversion in the heteroallelic diploid yeast strain saccharomyces cerevisiae d4 and sex-linked recessive lethals in drosophila melanogaster. whereas metronidazole exhibit ...1979154545
interesting and unusual features in the sequence of neurospora crassa mitochondrial tyrosine transfer rna.the mitochondrial tyrosine trna from neurospora crassa has been sequenced and found to have several interesting features: (i) it resembles prokaryotic rather than eukaryotic tyrosine trnas in that it possesses a large variable loop (loop iii); moreover, it can be quantitatively aminoacylated by escherichia coli tyrosyl-trna synthetase but not by yeast tyrosyl-trna synthetase. (ii) this trna differs from all trna's sequenced to date in lacking the a residue at position 14 and the constant purine ...1979154673
mediated mutagenesis of dimethylnitrosamine in neurospora crassa by various metabolic activation systems.four metabolic activation systems (growth mediated mycelium extract mediated, host mediated, and organ homogenate mediated) were used to study the mutagenic activity of dimethylnitrosamine (dmn) in both forward and reverse mutation systems in the ad-3 (adenine-3) region of neurospora crassa. dmn was not mutagenic in neurospora if conidia alone were treated. it was highly mutagenic, however, if conidia were treated with this compound under any of the four activation systems. quantitative differen ...1979154971
literature survey of bacterial, fungal, and drosophila assay systems used in the evaluation of selected chemical compounds for mutagenic activity.literature reports were surveyed, with results noted from experiments in seven nonmammalian assay systems used for the detection of mutagenicity or other related genetic effects. a comparison was made of the activities of 54 selected noncarcinogens, procarcinogens, and ultimate carcinogens as revealed by these test systems. of the compounds tested, 49 (91%) were active in one or more of the assays, and 42 (78%) were positive in at least one system without having to be metabolically activated. in ...1979155170
arrangement of the genes coding for ribosomal ribonucleic acids in neurospora crassa.we have cloned and characterized neurospora crassa ribosomal deoxyribonucleic acid (rdna). the rdna is found as a tandemly repeated 6.0-megadalton sequence. we have mapped a portion of the rdna repeat unit with respect to its sites for 13 restriction endonucleases and defined those regions coding for the 5. 8s, 17s, and 26s ribosomal ribonucleic acids (rrna's). we have also isolated several clones containing 5s rrna sequences. the 5s rrna coding sequences are not found within the rdna repeat uni ...1979155688
inactivation of neurospora crassa conidia by singlet molecular oxygen generated by a photosensitized reaction.photodynamic damage of neurospora crassa conidia was studied in the presence of the photosensitizing dye, toluidine blue o. conidia which germinated to form colonies decreased in number as irradiation time became longer. the photoinactivation of conidia was suppressed by azide, bovine serum albumin, and histidine, and was stimulated in deuterium oxide. wild-type conidia were less sensitive to the irradiation than albino conidia. in the wild-type, carotenoid-enriched conidia were more resistant a ...1979155692
mutagenicity and mutagenic specificity of metronidazole and niridazole in neurospora crassa.mutagenicity and mutagenic specificity of niridazole and metronidazole, two chemotherapeutic agents used in the treatment of human parasitic diseases, were studied with the ad-3 test system of neurospora crassa. the results show that neither compound is mutagenic in resting conidia. in growing vegetative cells, however, both compounds are mutagenic in neurospora crassa. genetic analysis of the mutants indicate that niridazole induces predominantly base-pair substitution mutations. none of the ni ...1979156240
constitutive expression in escherichia coli of the neurospora crassa structural gene encoding the inducible enzyme catabolic neurospora crassa the qa-2 gene, which encodes catabolic dehydroquinase, is under positive control exerted by the inducer quinic acid and an activator protein encoded in the closely linked qa-1 gene. in order to determine if this regulatory mechanism is maintained when the qa-2 gene is cloned on a recombinant plasmid and expressed in escherichia coli, molecular cloning experiments have been performed using dna isolated from a qa-1+ (inducible), a qa-1c (constitutive) and two qa-1 (non-inducib ...1979156301
ageing of neurospora crassa. viii. lethality and mutagenicity of ferrous ions, ascorbic acid, and malondialdehyde.ferrous ions were highly lethal and mutagenic to germinated conidia of neurospora crassa. at comparable survival, treatment with 0.2 mm ferrous ions was 14- and 50-fold more mutagenic than ultra-violet irradiation or x-rays, respectively, in the reversion of an inositol auxotroph. ascorbic acid alone (2 mm) was not reproducibly lethal and inhibited both the lethality and mutagenicity of ferrous ions. bovine superoxide dismutase (sod) completely inhibited the residual lethality of ferrous ascorba ...1979156825
nucleotide sequence and conserved features of the 5.8 s rrna coding region of neurospora crassa.the nucleotide sequence of neurospora crassa 5.8 s rdna and adjacent regions has been determined. the deduced 5.8 s rrna sequence of neurospora differs from the 5.8 s rrna sequence of saccharomyces cerevisiae at 13 of 158 residues. nine of these differences are clustered in a segment capable of forming a short hairpin secondary structure thought to be involved in the 28 s - 5.8 s rrna complex. these differences occur in pairs such that the potential secondary structure is preserved.1979156910
inducible and constitutive kynureninases. control of the inducible enzyme activity by transamination and inhibition of the constitutive enzyme by 3-hydroxyanthranilate.the inducible kynureninase from neurospora crassa is inactivated by incubation with l-alanine or l-ornithine. the inactivated enzyme is resolved to the apoenzyme by dialysis. reactivation of the apoenzyme is achieved by incubation with pyridoxamine 5'-phosphate plus pyruvate, as well as with pyridoxal 5'-phosphate. the kynurenine hydrolysis proceeds linearly in the presence of added pyridoxal 5'-phosphate, or pyridoxamine 5'-phosphate plus pyruvate. these findings indicate that the fungal induci ...1979158014
a study of the organisation of the ribosomal ribonucleic acid gene cluster of neurospora crassa by means of restriction endonuclease analysis and cloning in bacteriophage lambda.1. total neurospora crassa dna was restricted with endonucleases and fragments carrying rrna coding sequences were identified by hybridization with xenopus laevis ribosomal dna probes. 2. the repeating unit of the rrna gene cluster was found to be 8.6 kbp, arranged in a head-to-tail fashion. 3. digestion with hind iii yielded fragments of 3.4 kbp and 5.2 kbp and both were cloned. 4. digestion with eco ri yielded fragments of 2.2 kbp, 3.0 kbp and 3.4 kbp; the 3.0 kbp fragment was cloned. 5. seque ...1979158122
metabolic activations of dimethylnitrosamine by male and female mice and rats to metabolites mutagenic in neurospora crassa. 1979158139
rapid rna sequencing: nucleases from staphylococcus aureus and neurospora crassa discriminate between uridine and cytidine.using end-labelled rna, significant changes in base specificity of three nucleases have been detected under defined conditions. staphylococcus aureus nuclease at ph 3.5 without ca++ cleaves all pyr-n bonds more uniformly and efficiently than rnase a, without any preference for pyr-a bonds. at ph 7.5 in 10 mm ca++ this enzyme cleaves all n-c and n-g bonds slowly, whereas n-u and n-a bonds are hydrolyzed rapidly. hence, the base at the 3'- or at the 5'-side of a phosphodiester bond can determine t ...1979158747
cell-free synthesis of the mitochondrial adp/atp carrier protein of neurospora crassa.adp/atp carrier protein was synthesized in heterologous cell-free systems programmed with neurospora poly(a)-containing rna and homologous cell-free systems from neurospora. the apparent molecular weight of the product obtained in vitro was the same as that of the authentic mitochondrial protein. the primary translation product obtained in reticulocyte lysates starts with formylmethionine when formylated initiator methionyl-trna (fmet-trnafmet) was present. the product synthesized in vitro was r ...1979159174
mapping and cloning of neurospora crassa mitochondrial transfer rna genes.we have obtained collections of recombinant escherichia coli plasmids containing restriction fragments of neurospora crassa mitochondrial dna cloned into pbr322. by hybridization of 32p end-labeled total mitochondrial trnas and seven different purified trnas to restriction digests of mitochondrial dna and of recombinant plasmids carrying specific restriction fragments, we have located the trna genes on the mitochondrial dna. we have found that the mitochondrial trna genes are present in two majo ...1979159308
efficient transformation of neurospora crassa by utilizing hybrid plasmid efficient transformation system has been developed for neurospora crassa that uses spheroplasts and pvk88 plasmid dna. pvk88 is a recombinant escherichia coli plasmid carrying the n. crassa qa-2(+) gene which encodes catabolic dehydroquinase (3-dehydroquinate hydro-lyase, ec and is part of the qa gene cluster. the recipient strain carries a stable qa-2(-) mutation and an arom-9(-) mutation, thus lacking both catabolic and biosynthetic dehydroquinase activities. transformants were se ...1979159454
characterization of variant neurospora crassa mitochondrial dnas which contain tandem reiterations.two variant mtdna types ((types iia and hi-10) have been identified in individual subcultures of the extra-nuclear [poky] mutant of neurospora crassa. eco ri digests of type iia mtdna are characterized by an extra band, alpha, mr = 1.4 mdal, which arises from tandemly inserted reiterations of a 1.4 mdal sequence. restriction enzyme analysis and southern hybridization experiments show: that the 1.4 mdal repeats are located at the junction of eco ri-4 and -6, that the repeats contain sequences ord ...1979160287
increased expression of a eukaryotic gene in escherichia coli through stabilization of its messenger rna.the expression of a cloned eukaryotic gene [catabolic dehydroquinase (3-dehydroquinate hydro-lyase, ec (qa-2+) from neurospora crassa] is dramatically increased (as much as 100-fold) in escherichia coli strains deficient in polynucleotide phosphorylase (pnp) (polynucleotide: orthophosphate nucleotidyltransferase, ec and rnase i (rna). the increased expression is controlled primarily by the absence of polynucleotide phosphorylase and appears to be specific for the eukaryotic ge ...1979160556
metallothionein: an exceptional metal thiolate protein.metallothioneins are unusual, low molecular weight proteins of extremely high sulphur and metabl content. they occur in substantial quantity and in multiple variant forms in parenchymatous tissues (liver, kidney, intestines) of vertebrates and certain microorganisms (neurospora crassa, yeast). they are though to play a central role in the cellular metabolism of metals such as zinc, copper and cadmium. all mammalian forms studied are single chains with 20 cysteinyl residues among a total of 61 am ...1979162047
genetic effects of pr toxin in eukaryotic microorganisms.the genetic activity of pr toxin, a mycotoxin from penicillium roqueforti, was studied in saccharomyces cerevisiae and neurospora crassa. the results show that pr toxin, without enzymic activation, causes gene conversion in s. cerevisiae strains d4 and d7, reverse mutation in s. cerevisiae strain d7 and n. crassa strain n24, and mitotic crossing-over in s. cerevisiae strain d7, in the log phase cells of s. cerevisiae the effects are more pronounced at alkaline than at acid ph. the active site re ...1979162284
structural defects in rat liver deoxyribonucleic acid. endogenous single-strained regions in comparison with damage induced in vivo by a carcinogen.rat liver dna may be separated into two fractions by stepwise elution from benzoylated-deae-cellulose with nacl and caffeine solutions respectively. other studies using bacterical and yeast dna suggested that the first fraction contains native dna, whereas the second may exhibit some degree of single-stranded character. in the present experiments, chromatography of dna was monitored by labelling in vivo with [methyl-3h]thymidine in rats previously subjected to partial hepatectomy. in animals kil ...1979486085
repair of daughter strand gaps in nascent dna from mouse epidermal cells treated with dihydrodiol epoxide derivatives of benzo[a]pyrene.alkaline sucrose gradient analysis of [methyl-3h]thymidine-pulse-labeled dna was used to study the effect of (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (benzo[a]pyrene-diol epoxide i), a potent mutagen and carcinogen, and (+/-)-7 beta,8 alpha-dihydroxy-9 beta,10 beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (benzo[a]pyrene-diol epoxide ii), a weaker mutagen and carcinogen, on the size of newly synthesized dna in primary cultures of mouse epidermal cell ...1979508766
nuclear mutants of neurospora crassa temperature-sensitive for the synthesis of cytochrome aa3. i. isolation and preliminary characterization.three nuclear mutants of neurospora crassa, temperature-sensitive for the synthesis of cytochrome aa3 have been isolated. when grown at 41 degrees c the mutants have large amounts of kcn-insensitive respiration, reduced amounts of cytochrome aa3 and cytochrome c oxidase activity, and grow more slowly than wild-type cultures grown at the same temperature. when the mutants are grown at 23 degrees c, they are virtually indistinguishable from wild-type strains. the mutants were selected on the basis ...1979216900
a regulatory system controlling the production of cytochrome aa3 in neurospora crassa.the mitochondria of the cyt-2-1, cya-3-16, cya-4-23 and 299-1 nuclear mutants and the [mi-3] and [exn-5] cytoplasmic mutants of neurospora crassa are deficient in cytochrome aa3, while the cyb-1-1 and cyb-2-1 mutants have mitochondrial b-cytochrome deficiencies. however, the mitochondria from cyb-1-1 cyt-2-1, cyb-1-1 [mi-3] and cyb-2-1 [mi-3] double mutants contain 30% to 50% of the amount of cytochrome aa3 that is present in mitochondria from wild-type; i.e. cyb-1-1 and cyb-2-2 act as suppresso ...1979216899
extraction and quantification of solutes in solidified agar culture media.a method is described for determining the concentration of certain solutes in solidified culture media. the method is based upon the finding that under specified conditions the concentration of solute in an agar gel (c(g)) is related to the concentration of solute in a centrifugally extracted gel supernatant (c(s)) by the ratio, c(g)/c(s), which is characteristic for each solute. the method avoids direct assays of the gels and instead involves assaying the supernatants from inoculated and uninoc ...197916345342
organization of the qa gene cluster in neurospora crassa: direction of transcription of the qa-3 neurospora crassa, the enzyme quinate (shikimate) dehydrogenase catalyzes the first reaction in the inducible quinic acid catabolic pathway and is encoded in the qa-3 gene of the qa cluster. in this cluster, the order of genes has been established as qa-1 qa-3 qa-4 qa-2. amino-terminal sequences have been determined for purified quinate dehydrogenase from wild type and from uv-induced revertants in two different qa-3 mutants. these two mutants (m16 and m45) map at opposite ends of the qa-3 lo ...1979159203
ageing of neurospora crassa. ix. microviscosity properties of mitochondrial membranes during normal and abnormal growth and development of an inositol auxotroph.microviscosity of mitochondrial membranes of an inositol auxotroph of neurospora was measured by the method of shinitzky, employing the fluorescent probe diphenyl-hexatriene. with high concentration of inositol, growth, morphogenesis, and cellular and biochemical phenotypes of the auxotroph are normal; whereas with low concentrations, these characteristics become abnormal and cellular and clonal senescence ensue. during normal growth and development, the critical temperatures of phase transition ...1979156824
split gene for mitochondrial 24s ribosomal rna of neurospora crassa.the 60 kb circular mitochondrial genome of n. crassa has previously been shown to contain a single transcription unit for 17s and 24s rrna mapping within the largest eco ri fragment e1 (19.6 kb). this fragment was isolated from uncloned mitochondrial dna and further analyzed by cleavage with restriction endonucleases hind ii, hind iii, bam hi, pvu ii and bgi i, and by electron microscopy of rrna/dna hybrids. the resulting map shows a 2.3 kb intervening sequence interrupting the gene for 24s rrna ...1979156584
comparison of inducible and constitutive kynureninases of neurospora crassa.two types of kynureninase were isolated from neurospora crassa ifo 6068. the formation of one of them, which was separated from the inducible kynureninase by deae-cellulose chromatography, was independent of the presence of tryptophan in the growth medium. ouchterlony double-diffusion analysis and immunochemical titration indicated that the constitutive-type enzyme is immunologically different from the inducible enzyme. we confirmed by a selective assay method with antiserum that the addition of ...1979156178
biosynthesis of glycogen in neurospora crassa. chemical composition and binding to glycogen of udp-glucose: glycogen 4-alpha-glucosyltransferase. 1979156721
transmission of mitochondrial deoxyribonucleic acid in neurospora crassa sexual crosses.neurospora crassa mitochondrial deoxyribonucleic acid shows strict uniparental inheritance in sexual crosses, with a notable absence of mixtures and recombinant types that appear frequently in heteroplasmons.1979155689
nitrogen metabolite repression of nitrate reductase in neurospora crassa.the effect of different nitrogen compounds on the induction of reduced nicotinamide adenine dinucleotide phosphate-nitrate reductase was examined in neurospora crassa. whereas in the wild-type strain several amino acids and ammonia inhibit the formation of nitrate reductase, only glutamine, cysteine, and histidine are shown to inhibit the synthesis of nitrate reductase in a glutamine-requiring auxotroph. none of the amino acids inhibited nitrate reductase activity in vitro. the effects of cystei ...1979155687
characterization of the carbohydrate component of fraction i in the neurospora crassa cell wall.the carbohydrate portion of fraction i of the neurospora crassa cell wall has been analyzed for sugar composition by gas-liquid chromatography and colorimetric methods. the analysis was performed comparatively in a wild-type strain (rl 3-8a) and three morphological mutants: scumbo (fgsc 49), peak-2a (a mutant known to be allelic to biscuit), and ragged (fgsc 296). fraction i of all strains studied contains glucose, mannose, and galactose as the main sugars. uronic acids and amino sugars are also ...1979155686
regulation of glutamate dehydrogenases in nit-2 and am mutants of neurospora crassa.the regulation of the glutamate dehydrogenases was investigated in wild-type neurospora crassa and two classes of mutants altered in the assimilation of inorganic nitrogen, as either nitrate or ammonium. in the wild-type strain, a high nutrient carbon concentration increased the activity of reduced nicotinamide adenine dinucleotide phosphate (nadph)-glutamate dehydrogenase and decreased the activity of reduced nicotinamide adenine dinucleotide (nadh)-glutamate dehydrogenase. a high nutrient nitr ...197935517
the effects of vanadate on the plasma membrane atpase of neurospora crassa. 1979155060
permeability changes in membranes of neurospora crassa after freezing and thawing. 1979157849
the major intracellular alkaline deoxyribonuclease activities expressed in wild-type and rec-like mutants of neurospora crassa.over 95% of the deoxyribonuclease (dnase) activity of log-phase mycelia of neurospora crassa is expressed as single-strand (ss) specific endonucleolytic activity. this activity is associated with three nucleases (d1, d2, and d3) which after partial purification from extracts, express activity with double-strand (ds) dna as well. all three enzymes also degrade rna at approximately the same rates that they degrade ss-dna. d3 has been identified as endoexonuclease, an enzyme previously shown to hav ...1979157796
competitive inhibition of neurospora crassa chitin synthetase activity by tunicamycin. 1979157718
defective splicing of mitochondrial rrna in cytochrome-deficient nuclear mutants of neurospora crassa.recent studies have shown that the gene encoding the large (25 s) mitochondrial rrna of neurospora crassa contains an intervening sequence of 2-2.5 kilobases that is not present in the mature 25s mitochondrial rrna. earlier studies had provided evidence that mitochondrial rrnas in neurospora are synthesized via a 32s precursor rna that contains sequences for both the mature 19s and 25s rna species. the present work shows that the intervening sequence is not present in 32s rna. however, we have i ...1979156923
inhibition of the acid proteinase from neurospora crassa by diazoacetyl-dl-norleucine methyl ester, 1,2-epoxy-3-(4-nitrophenoxy)propane and pepstatin. 197938198
role of purine base excretion in regulation of purine pools.wild type and mutant strains of neurospora crassa excrete hypoxanthine, xanthine, and uric acid, but not adenine or inosine, when exogenous adenine is added to growing cultures. no detectable excretion occurs in the absence of adenine. the de novo pathway of purine biosynthesis was found to influence the excretion, in that a metabolic block immediately prior to imp significantly decreased the excretion, while a metabolic block immediately after imp significantly increased the excretion over that ...1979157418
biogenesis of mitochondrial membrane proteins in neurospora crassa. 1979223007
amino-acid sequence of copper-metallothionein from neurospora crassa. 1979162453
demonstration of myo-inositol-1-phosphate synthase and its assumed defective variant in various neurospora crassa strains by immunological methods.immunological experiments were performed to demonstrate myo-inositol-1-phosphate synthase (ec and its assumed defective variant in various neurospora crassa stains. an enzymatically inactive protein fraction was isolated from the inl-mutant by the same procedure as that of the enzyme. it consisted of several components by gel electrophoresis, and produced a positive immune reaction demonstrated by immunodiffusion using immune sera produced against the enzyme. using immunodisc gel electr ...1979162120
isolation of 4 alpha-methyl-5 alpha-ergosta-8,24(28)-dien-3 beta-ol from ester fractions of nutritionally deprived neurospora crassa.a method of isolating pure fractions of 4 alpha-methyl-5 alpha-ergosta-8,24(28)-dien-38-ol for sterol intermediate studies is described. starvation cultures of neurospora crassa readily incorporate exogenous mevalonic acid into the sterol ester fraction. isolation involves a simple solvent extraction and two chromatograms. only the ester fraction yielded the required purity. radioactive 4 alpha-methyl-5 alpha-ergosta-8,24(28)-dien-3 beta-ol is readily produced from dl-[2-14c] mevalonic acid.1979161433
mitochondrial ribosome assembly in neurospora crassa: mutants with defects in mitochondrial ribosome assembly. 1979161342
electron cytochemical detection of two dehydrogenase activities in neurospora crassa. 1979157813
mitochondrial ribosomes of neurospora crassa: isolation, analysis, and use. 1979156869
whole cells for the study of transport linked to membrane potential: neurospora crassa. 1979156855
mitochondrial atpase complex from neurospora crassa. 1979156842
preparation of neurospora crassa mitochondria. 1979156831
laboratory of physiological chemistry, state university groningen, obtain more information about the arrangement of hind iii restriction fragments in the trna-rrna region of the neurospora crassa mitochondrial (mt) dna we have cleaved the mtdna with hpa i and hind ii. we could construct additional cleavage maps for these enzymes. hybridization of rrnas to hind ii fragments confirmed the existence of an intervening region of about 2,300 basepairs in the 24s rrna (hahn et al., cell, in press). about seven trna genes, among which the genes for trna1ser and trna ...1979156351
the biosynthesis of the free sterols and sterol esters of neurospora crassa.the composition of the free and esterified sterols in neurospora crassa was examined as a function of incubation time in starvation medium containing [2-14c]mevalonic acid. the 14c incorporation was monitored in nuclear methylated and 4,14-desmethyl sterol fractions. after 7 h incubation, sterol esterification had increased from an initial 5% in the log phase culture to 48% of the total sterol pool, with a concomitant decrease in free sterols. the relationship of the free and esterified sterol c ...1979156577
circadian rhythms in neurospora crassa: effects of unsaturated fatty acids.employing a fatty acid-requiring strain (bd csp cel) of neurospora crassa, the 21.5-h period of the circadian spore-forming rhythm was manipulated by fatty acid supplementation. the addition to the medium of an unsaturated fatty acid (oleic, linoleic, or linolenic acid) lengthened the period to 26, 40, or 33 h, respectively. ther period-lengthening effect of linoleic acid was proportional to its concentration up to 1.3 x 10(-4) m, and also was reversed by the addition to the medium of a saturate ...1979154511
selection of succinic dehydrogenase mutants of neurospora crassa.a method is described which permits the selection of mutants of neurospora crassa that are deficient in succinic dehydrogenase activity. the method relies on the observation that succinic dehydrogenase-deficient strains fail to reduce the dye nitrotetrazolium blue when overlaid with the dye in the presence of succinate and phenazine methosulfate. wild-type colonies reduced the dye and turned blue, whereas mutant colonies remained colorless. in this communication we present studies of a mutant, s ...1979154510
some properties of vacuoles isolated from neurospora crassa slime variant.a method for the isolation of vacuoles based on polybase induced lysis of protoplasts of the cell wall deficient neurospora crassa slime variant is described. isolated vacuoles are characterized by 12 to 50 times increased specific activities of several hydrolases as compared with the total homogenate of protoplasts. total alpha-amino nitrogen, arginine, and polyphosphate are also greatly enriched in these vacuoles. vacuoles are equipped with a permease for the transport of basic amino acids acr ...1979154878
the relationship between synaptinemal complexes, recombination nodules and crossing over in neurospora crassa bivalents and translocation quadrivalents.reconstruction of serially sectioned zygotene and pachytene nuclei has allowed the estimation of both the number and position of central component recombination nodules in the synaptinemal complexes of two chromosomally different strains of neurospora crassa. in both strains the number of nodules is that expected if each nodule represents one crossover event (50 map units). the distribution of nodules within the arms of bivalents shows evidence of centromeric repulsion and telomeric localization ...197917248878
regulation of neurospora crassa nucleosidases by some environmental factors.enzymic cleavage of n-glycosidic bonds of amp, gmp, and inosine by the cell-free extracts of neurospora crassa has been studied. the enzymic activities with these substrates appear to be discrete from one another. the levels of these enzymes in the cell vary with age, and are dependent upon the inoculum size, aeration rate, and phosphate level in the medium. glucose (or ribose) controls the phosphate-mediated repression of all the three nucleosidases of this fungus.1979231866
adenylyl cyclase deficient cr-1 (crisp) mutant of neurospora crassa: cyclic amp-dependent nutritional deficiencies.the inability to synthesize cyclic amp drastically affects the nutritional metabolism of neurospora crassa. the adenylyl cyclase-less mutant cr-1 (crisp) did not utilize several carbon sources, including glycerol, mannitol, arabinose, and casaminoacids. however, in glucose or acetate it grew as well as the wild type. the following evidence suggested that these nutritional deficiencies were a direct result of the cr-1 mutation: (i), in crosses to wild type they segregated together with the crisp ...1979230797
alkaline deoxyribonucleases released from neurospora crassa mycelia: two activities not released by mutants with multiple sensitivities to mutagens.three major alkaline deoxyribonuclease (dnase) activities have been identified in sorbose-containing liquid culture medium in which wild-type neurosporacrassa were grown: dnase a, a ca++dependent endonuclease of molecular weight 65,000 daltons which has no specificity for single- or double-stranded dna (ss-dna or ds-dna) and no activity with rna; dnase b, a mg++-dependent single-strand specific exonuclease of molecular weight 78,000 daltons active with both ss-dna and rna; dnase c, a divalent me ...1979154656
nature of 6-methylpurine inhibition and characterization of two 6-methylpurine-resistant mutants of neurospora crassa.6-methylpurine, an analog of adenine, inhibits the growth of neurospora crassa. from kinetic studies it was found that 6-methylpurine is converted to its nucleotide form by adenine phosphoribosyltransferase (ec, and inhibits the de novo purine biosynthesis. adenine relieves the growth inhibition caused by 6-methylpurine, whereas hypoxanthine is not very effective. studies dealing with hypoxanthine utilization in the presence of 6-methylpurine indicated a severely reduced uptake of hypox ...1979153898
Displaying items 1501 - 1600 of 5889