TitleAbstractYear(sorted ascending)
developmental defects resulting from arginine auxotrophy in aspergillus nidulans.a mutant of aspergillus nidulans, isolated for inability to form asexual spores (conidia) on complete medium, was found to regain the ability to conidiate if the medium was supplemented with arginine. on minimal medium the mutant required arginine for growth but at a much lower concentration than that required for conidiation. this mutant, designated argb12, thus defines a phase-critical gene, i.e. a gene whose function is in greater demand for development than for growth. in addition to its aco ...19836363619
bifunctionality and polarized infidelity at the hisb locus of aspergillus nidulans.the histidine (hisb) locus of aspergillus nidulans is unusual in two ways. firstly, it is bifunctional; besides coding for imidazole glycerol phosphate (igp) dehydrase, it is required for the production of ascospores (fertility). it appears, therefore, to be partly homologous to the hisb locus of salmonella typhimurium, which codes for igp dehydrase and histidinol phosphate phosphatase. secondly, during meiosis it is often inaccurately transmitted to the progeny (infidelity). this phenomenon may ...19846363882
disruptive effects of ethyl alcohol on mitotic chromosome segregation in diploid and haploid strains of aspergillus identify, with certainty, the primary genotoxic effects of ethanol, condidia from diploid strains of aspergillus nidulans were treated during early germination with ethyl alcohol, and all the resulting segregants from large samples were analysed in detail. results were identical whether technical grade (95%), or highly purified 'absolute', alcohol was diluted to obtain the effective low levels of ethanol (3-6%). this makes it unlikely that trace contaminants, rather than ethanol itself, cause ...19846363912
separation and characterization of pyrimidine deoxyribonucleoside 2'-hydroxylase and thymine 7-hydroxylase from aspergillus nidulans.partially purified preparations from aspergillus nidulans were shown to catalyze two alpha-ketoglutarate dependent dioxygenase reactions: the pyrimidine deoxyribonucleoside 2'-hydroxylase (ec and the thymine 7-hydroxylase (ec reactions. these reactions showed an absolute requirement for alpha-ketoglutarate and molecular oxygen and were stimulated by fe(ii), ascorbate and catalase. both reactions demonstrated a stoichiometry such that for each mole of substrate (deoxyribonuc ...19846370754
genotoxicity of the free-radical producers ccl4 and lipoperoxide in aspergillus nidulans.the false negative compounds, carbon tetrachloride and linoleic acid peroxide, induce somatic segregation in a. nidulans, but are negative or weak in inducing gene mutation in a haploid strain of the same organism. the other carcinogen tested, chcl3, was negative in both tests. a model involving free-radical formation is proposed to explain the results. finally, cysteamine, a free-radical scavenger, could partially counteract the genotoxicity of ccl4. the existence of carcinogens, predominantly ...19846371516
evidence for two control genes regulating expression of the quinic acid utilization (qut) gene cluster in aspergillus nidulans.the first three steps in quinic acid degradation in aspergillus nidulans are catalysed by highly inducible enzymes encoded by a gene cluster regulated by an adjacent control region. analysis of two non-inducible mutants has been done in diploid strains, where quta8 is recessive and all three enzyme activities are fully induced in heterozygous quta8/quta+ diploids. in contrast, quta4/quta+ heterozygous diploids show semi-dominance of the mutant allele, giving markedly diminished growth on quinic ...19846374025
interactions of ribosomal antibiotics and informational suppressors of aspergillus nidulans.strains of aspergillus nidulans containing informational suppressors were grown on medium containing antibiotics known to affect protein synthesis at the ribosomal level. these strains reacted in the anticipated manner: presumed ribosomal suppressors suaa101, suaa105, suac109 and sua-115 were sensitive or even hypersensitive to aminoglycoside antibiotics, whereas presumed trna-like suppressors suab111, suad103 and d108 were only slightly sensitive or wild-type in response. hygromycin and paromom ...19846374026
spontaneous duplications and transpositions of a large chromosome segment in aspergillus nidulans.spontaneous revertants of the leaky ade20 mutant of aspergillus nidulans were obtained as vigorous sectors emerging from stunted colonies on adenine-free medium. among the genetically heterogeneous sectors up to about 20% were recognized unequivocally as having an additional chromosome segment bearing ade20; two doses of this leaky allele permitted growth without added adenine. eleven spontaneous duplication strains of independent origin were analysed genetically. eight carried the duplicate seg ...19846374027
s-phase, g2, and nuclear division mutants of aspergillus nidulans.twenty-two temperature-sensitive cell cycle mutants of the fungus aspergillus nidulans, which block in interphase at restrictive temperature, were analyzed by the reciprocal shift method of jarvik and botstein (proc. nath acad. sci. u.s.a. 70:2046-2050, 1973) and hereford and hartwell (j. mol. biol. 84:445-461, 1974) to determine whether these mutations were blocked at the g1, s, or g2 phase of the cell cycle. we found five mutants to be blocked in s and nine to be blocked in g2. two of the g2 m ...19846376468
genetic and environmental modification of gene expression in the brla12 variegated position effect mutant of aspergillus nidulans. 19846378720
evidence for a nonsense mutation at the niad locus of aspergillus nidulans. 19846381230
effects of mitotic and tubulin mutations on microtubule architecture in actively growing protoplasts of aspergillus nidulans.we used immunofluorescent microscopy to characterize microtubule (mt) architecture in wild-type and mutant protoplasts of aspergillus nidulans at interphase and at mitosis. because the visualization of mts by immunofluorescence is technically difficult in intact hyphae of a. nidulans, we developed a method for removing the cell wall under conditions that do not perturb cell physiology, as evidenced by the fact that the resulting protoplasts undergo nuclear division at a normal rate and that cell ...19846381507
mutations affecting the sulphur assimilation pathway in aspergillus nidulans: their effect on sulphur amino acid metabolism.several sul-reg mutants of aspergillus nidulans isolated as constitutive for arylsulphatase were studied with respect to the regulation of enzymes involved in cysteine and homocysteine synthesis and to the pool of sulphur amino acids. all mutants examined showed a decreased concentration of glutathione as compared with the wild type, and all mutants, with one exception, had a decreased total pool of sulphur amino acids. the results suggest that the mutants are leaky in the sulphate assimilation ...19846381643
induction of somatic segregation by halogenated aliphatic hydrocarbons in aspergillus nidulans.8 halogenated aliphatic hydrocarbons were assayed for their ability to induce somatic segregation in the mould aspergillus nidulans. induction of haploidization, mitotic non-disjunction and mitotic crossing-over was studied in heterozygous colonies exposed to the tested chemicals through the detection and phenotypic analysis of segregated sectors. the results obtained show that 1,2-dibromoethane induced all kinds of segregated sectors; 1,2-dichloroethane, allyl chloride, 2-chloroethanol, 2,2-dic ...19846387478
mutants of aspergillus nidulans blocked at an early stage of sporulation secrete an unusual metabolite.mutants of aspergillus nidulans defective in conidiation (asexual sporulation) can be classified according to whether they are blocked before or after induction of conidiation. mutants blocked before induction (preinduction mutants) appear to be unable to respond to the inducing stimulus and thus are defective in one of the earliest events in the sporulation process. three preinduction mutants have been isolated and characterized. each was found to exhibit the same pleiotropic phenotype: they al ...19846389494
further studies on protoplast fusion and interspecific hybridization within the aspergillus nidulans group.hybridization of eight species of the aspergillus nidulans group was attempted using auxotrophic mutants and protoplast fusion methods. viable fusion products were obtained from eight crosses. allodiploid hybrids were recovered from crosses involving a. nidulans with a. rugulosus, a. quadrilineatus, a. nidulans var. echinulatus and a. violaceus, although some mutants only gave heterokaryons. crosses involving these latter species also gave heterokaryons. crosses between a. nidulans and a. unguis ...19846389760
structure and regulated expression of the spoc1 gene cluster from aspergillus nidulans.we have previously described the organization of a 13.3 kb region of the aspergillus nidulans genome, designated spoc1, coding for multiple poly(a)+ rnas that accumulate in asexual spores but not in somatic cells. we have determined the limits of the spoc1 gene cluster by investigating the transcriptional features of 53 kb of chromosomal dna. this segment of the genome codes for at least 19 poly(a)+ rnas, some of which are transcribed from overlapping regions. the area of developmental regulatio ...19846392570
regulation of pyrimidine salvage in aspergillus nidulans: a role for the major regulatory gene are a mediating nitrogen metabolite repression.the synthesis of thymine 7-hydroxylase, an alpha-ketoglutarate dependent dioxygenase, is subject both to nitrogen metabolite repression and to oxygen repression, while synthesis of the other pyrimidine salvage pathway dioxygenase, pyrimidine deoxyribonucleoside 2'-hydroxylase, is subject to neither. are a300, an allele of the positive acting regulatory gene are a mediating nitrogen metabolite repression in aspergillus nidulans, considerably elevates levels of thymine 7-hydroxylase, probably alle ...19846394961
purification and properties of purine hydroxylase ii from aspergillus nidulans.purine hydroxylase ii from aspergillus nidulans has been purified to near homogeneity. the enzyme has a pi of 5.7, a molecular weight of 300,000, and two subunits with molecular weight of 153,000 each. the enzyme contains 2 fad, 2 molybdenum atoms, and 4 (2 fe-2s) iron-sulfur centers per molecule and exhibits broad specificity for reducing and oxidizing substrates. among the more notable characteristics are the ability to oxidize hypoxanthine and nicotinic acid but not xanthine and virtually com ...19846367661
transformation of aspergillus nidulans by using a trpc plasmid.we constructed a chimeric plasmid carrying a complete copy of the trifunctional trpc gene from the ascomycete fungus aspergillus nidulans. this plasmid, designated phy201, replicates in escherichia coli, where it confers resistance to ampicillin and chloramphenicol and complements trpc mutants lacking phosphoribosylanthranilate isomerase activity. we used phy201 to transform an a. nidulans trpc- strain to trpc+ at frequencies of greater than 20 stable transformants per microgram of dna. southern ...19846324193
identification of the probable coding region for exon 2 of cytochrome oxidase polypeptide i from aspergillus nidulans mitochondrion.hypothetical protein urfe of aspergillus nidulans mitochondrion is homologous with the amino end of cytochrome oxidase (ec polypeptide i. unidentified reading frame urfe does not contain a suitable initiation codon and codes for a protein with a length of only 91 residues, corresponding to about 20% of cytochrome oxidase polypeptide i. it is proposed that this region codes for the second exon of the cox 1 gene of aspergillus mitochondrion. possible candidates for the 2- to 3-residue ami ...19846324773
cloning of nitrate reductase genes from the cyanobacterium anacystis nidulans.anacystis nidulans, a non-nitrogen-fixing cyanobacterium, can fulfill its nitrogen requirement by the assimilation of nitrate. the first step in the pathway, the reduction of nitrate to nitrite, is catalyzed by the molybdo-protein nitrate reductase. in this study, newly developed techniques for gene cloning in a. nidulans r2 were used for the isolation of two genes involved in nitrate reduction. one gene was cloned by complementation of the corresponding mutant; the other gene was picked up from ...19846330039
sequence homology and structural similarity between cytochrome b of mitochondrial complex iii and the chloroplast b6-f complex: position of the cytochrome b hemes in the membrane.the amino acid sequences of cytochrome b of complex iii from five different mitochondrial sources (human, bovine, mouse, yeast, and aspergillus nidulans) and the chloroplast cytochrome b6 from spinach show a high degree of homology. calculation of the distribution of hydrophobic residues with a "hydropathy" function that is conserved in this family of proteins implies that the membrane-folding pattern of the 42-kilodalton (kda) mitochondrial cytochromes involves 8-9 membrane-spanning domains. th ...19846322162
optical and electron paramagnetic resonance spectroscopic studies on purine hydroxylase ii from aspergillus nidulans.purine hydroxylase ii from aspergillus nidulans contains a molybdenum cofactor very similar to that found in a number of other molybdenum-containing hydroxylases. (a. nidulans contains two purine hydroxylases, i and ii, related to each other by possession of a common cofactor and overlapping substrate specificity.) addition of reducing substrates effects bleaching of the visible absorption spectrum of the enzyme, the decrease in absorbance at 450 nm being linearly proportional to that at 550 nm. ...19846322698
amino acid sequence of a new mitochondrially synthesized proteolipid of the atp synthase of saccharomyces cerevisiae.the purification and the amino acid sequence of a proteolipid translated on ribosomes in yeast mitochondria is reported. this protein, which is a subunit of the atp synthase, was purified by extraction with chloroform/methanol (2/1) and subsequent chromatography on phosphocellulose and reverse phase h.p.l.c. a mol. wt. of 5500 was estimated by chromatography on bio-gel p-30 in 80% formic acid. the complete amino acid sequence of this protein was determined by automated solid phase edman degradat ...19846323165
photoacoustic spectroscopy of anacystis nidulans. iii. detection of photosynthetic activities.photosynthetic activities of anacystis nidulans can be detected by photoacoustic spectroscopy. algae treated by a photosynthetic inhibitor are used to provide the signal from the photochemically inactive sample. the results of these measurements correspond well with the activities which can be monitored by conventional biochemical assays. acoustic data from a. nidulans are used to obtain the action spectrum for photochemical energy storage. it is concluded that phycocyanin harvests light for bot ...19846421239
pyruvate carboxylase from aspergillus nidulans. effects of regulatory modifiers on the structure of the enzyme.a method is described for purification of pyruvate carboxylase from aspergillus nidulans by affinity chromatography on monomeric avidin-sepharose. the purified enzyme is homogeneous as judged by electrophoretic and immunochemical analysis. the sub-unit mr determined by electrophoresis in the presence of sodium dodecyl sulphate is 133000 +/- 5000. electron microscopic analysis of purified a. nidulans pyruvate carboxylase after negative staining with uranyl acetate reveals the presence of molecule ...19846421580
a convener role for the cnxh gene specified component in the nadph-nitrate reductase fron aspergillus nidulans.the role of the cnxh+ gene specified polypeptide in the formation and function of the nadph-nitrate reductase in aspergillus nidulans was examined with the use of two complementing mutant strains which were grown as forced heterocaryons in the presence of nitrate. the niad-421 structural gene mutant and the cnxh-318 co-factor gene mutant produce two components of the nadph-cytochrome c reductase co-activity which can be distinguished by their enzymatic and physical behavior. this combination ena ...19846423961
aspergillic acids produced by mixed cultures of aspergillus flavus and aspergillus nidulans.a mixed culture of aspergillus nidulans (gh79) and aspergillus flavus (cmi 91019b) produced two antibiotics, designated vi and vii, which were not elaborated when either fungus was grown alone. chemical and spectroscopic analysis of vi, the major component, indicated that this compound was identical to hydroxyaspergillic acid. the minor component, vii, was produced in too low a yield for its identity to be established. however, partial characterization suggests that this antibiotic also belongs ...19846427396
the nucleotide sequences of the 5 s rrnas of seven molds and a yeast and their use in studying ascomycete phylogeny.the sequences of the 5 s rrnas isolated from 8 ascomycete species belonging to the genera aspergillus, penicillium, acremonium and candida are reported. two of the examined strains each yielded a mixture of 3 slightly different 5 s rnas, which were individually sequenced after fractionation. a previously published sequence for aspergillus nidulans 5 s rna was found to contain errors. reconstruction of an evolutionary tree based on 5 s rna sequences showed that the 16 presently examined ascomycet ...19846429642
vanadate and dicyclohexylcarbodiimide insensitive proton extrusion from oxygen pulsed cells of the cyanobacterium anacystis nidulans.oxygen pulses applied to dark anaerobic suspensions of anacystis nidulans provoked immediate acidification of the external medium. the reaction was inhibited only 75% by dicyclohexylcarbodiimide and 7-chloro-4-nitrobenz-2-oxa-1,3-diazole at concentrations which completely arrested all oxidative phosphorylation. carbonyl cyanide m-chlorophenylhydrazone eliminated the acidification of oxygen pulsed cell suspensions while ortho-vanadate and diethylstilbestrol had no effect. no lag occurred between ...19846433918
regulation of the nitrate reductase level in anacystis nidulans: activity decay under nitrogen stress.the in vivo stability of ferredoxin-nitrate reductase from the cyanobacterium anacystis nidulans under conditions of inhibited protein synthesis has been studied in nitrate-grown cells. a light-promoted rapid decay in cellular nitrate reductase activity took place in the absence of any added nitrogen source, but not in the presence of nitrate, nitrite, or ammonium. the inactivation process seemed to proceed in two sequential steps. the first step required both light and oxygen, and was inhibited ...19846437330
[fatty acid composition of the lipids in fungi of the genus aspergillus developing on mineral media with different carbon sources].this work was aimed at studying the effect of different carbon sources in the composition of mineral media on the growth of fungi belonging to the aspergillus genus and on the fatty acid composition of their lipids. a chemically-defined medium with glucose was shown to be optimal for the growth of 18 aspergillus strains and for the synthesis of lipids by them. the fatty acid composition of lipids was studied when the fungi grew in media with different carbon sources. the lipids were shown to con ...19846442390
[in vitro comparative study of the sensitivity of aspergillus to antifungal agents].minimum inhibitory concentrations (mic) of amphotericin b, 5-fluorocytosine, miconazole, tioconazole, econazole and ketoconazole were determined for 310 aspergillus strains belonging to four different species isolated from clinical specimens. econazole exhibited the best in vitro activity with mic less than or equal to 3.12 micrograms/ml for 96% of strains and less than or equal to 1.56 micrograms/ml for 68%. for amphotericin b, 69% of strains were less than or equal to 1.56 micrograms/ml and, f ...19846462761
nondisjunction induced in mouse spermatogenesis by chloral hydrate, a metabolite of trichloroethylene.the effects of chloral hydrate (ch), an in vivo metabolite of trichloroethylene, have been evaluated by cytogenetic observations of mouse secondary spermatocytes after ip treatment with 82.7, 165.4, or 413.5 mg/kg bw. hyper-haploid metaphases have been scored to determine whether previous observations in various nonmammalian organisms about an effect of this drug on the mitotic spindle could be confirmed in mice. at each dose, the frequencies of hyper-haploid cells have been estimated to assess ...19846479114
isolation of aneuploid-generating mutants of aspergillus nidulans, one of which is defective in interphase of the cell cycle.a method is described for isolating mutants potentially defective in loci involved in mitotic chromosome segregation. conditional lethal, heat-sensitive (42 degrees ) mutants were assayed at a subrestrictive temperature of 37 degrees for an inflated production of colonies displaying phenotypes and behavior patterns of whole chromosome aneuploids. of 14 mutants, three showed specificity for one disomic phenotype, whereas 11 generated colonies mosaic for different aneuploid phenotypes. this latter ...19846479583
transhyphal electrical currents in fungi.representative mycelial fungi from the phycomycete, ascomycete and basidiomycete groups (achlya bisexualis, neurospora crassa, aspergillus nidulans, schizophyllum commune and coprinus cinereus) all generated steady electrical currents around their hyphal tips; the generation of a transhyphal ion current may therefore be a universal characteristic of hyphal growth. as with all other tip growing organisms, positive current always entered apically and left distally; non-growing hyphae did not drive ...19846520604
cytochrome b gene of neurospora crassa mitochondria. partial sequence and location of introns at sites different from those in saccharomyces cerevisiae and aspergillus nidulans.we have sequenced a 2614-base pair fragment of the neurospora crassa mitochondrial dna which contains part of the structural gene for apocytochrome b. this gene is split by at least two introns. the sequence reported here begins within one intron, extends through the next exon, another intron 1276 base pairs long, and the last exon which encodes the cooh terminus of cytochrome b. within the 254 amino acids encoded by the two exons, there is a high degree of sequence conservation, 81%, with cytoc ...19846231283
genetic studies in micro-organisms producing beta-lactam antibiotics. 19846237946
cloning and mapping of fourteen different dna fragments containing aspergillus nidulans 5s rrna genes.fourteen different plasmids hybridizing to aspergillus nidulans 5s rrna were isolated from a gene bank obtained after cloning sau3a partial digests of a. nidulans dna in a yeast--escherichia coli vector, pbb29. the restriction maps of these plasmids were determined. the size of the cloned fragments was 2.7-9.5 kb, 12 of the plasmids were found to code for single 5s rrna genes and 2 coded for 2 genes. no similarity of the sequences surrounding the 5s rrna genes was found by restriction mapping.19846205550
polyamines. 19846206782
specificity of antigens from pathogenic aspergillus species. ii. studies with line immunoelectrophoresis.somatic (mycelial) and metabolic (culture filtrate) antigens of aspergillus flavus, a. fumigatus, a. nidulans, a. niger and a. terreus were compared by line immunoelectrophoresis with sera from patients with allergic bronchopulmonary aspergillosis (abpa) or aspergilloma, or from immunized animals. number of lines observed when tested with human sera were similar for somatic and metabolic preparations of a. fumigatus, but up to 33 lines were present when both types of antigens were tested simulta ...19846209814
active rna: rna enzymes in rna splicing and processing. 19846210116
aspergillus contains multiple tubulin genes.previous work with benomyl-resistant mutants of aspergillus nidulans has demonstrated that the bena locus is a structural gene for beta-tubulin. two of the bena mutants, bena22 and bena85, show altered electrophoretic mobilities on two-dimensional gels for two beta-tubulins (designated beta 1 and beta 2). these shifts of the beta 1- and beta 2-tubulins uncover a spot in the region where wild-type beta-tubulins migrate that is occluded on gels of wild-type extracts by the beta 1- and beta 2-tubul ...19846210290
three variant introns of the same general class in the mitochondrial gene for cytochrome oxidase subunit 1 in aspergillus nidulans.the oxia gene of aspergillus nidulans, coding for cytochrome oxidase subunit 1, is shown by dna sequencing to contain three introns. an aug start codon is not present at the beginning of the sequence, suggesting that either another codon, possibly the four base codon auga, is used for initiation or there is a further short intron between the true start codon and the beginning of the recognisable coding region. the second and third introns have long open reading frames, which could code for matur ...19846092056
the mitochondrial genome of the fission yeast schizosaccharomyces pombe: highly homologous introns are inserted at the same position of the otherwise less conserved cox1 genes in schizosaccharomyces pombe and aspergillus nidulans.the dna sequence of the second intron in the mitochondrial gene for subunit 1 of cytochrome oxidase (cox1), and the 3' part of the structural gene have been determined in schizosaccharomyces pombe. comparing the presumptive amino acid sequence of the 3' regions of the cox1 genes in fungi reveals similarly large evolutionary distances between aspergillus nidulans, saccharomyces cerevisiae and s. pombe. the comparison of exon sequences also reveals a stretch of only low homology and of general siz ...19846092057
triton x-114 phase fractionation of membrane proteins of the cyanobacterium anacystis nidulans r2.the thylakoid polypeptides of the cyanobacterium anacystis nidulans r2 were analyzed by triton x-114 phase fractionation [c. bordier (1981) j. biol. chem. 256, 1604-1607, as adapted for photosynthetic membranes by t.m. bricker and l.a. sherman (1982) febs lett. 149, 197-202]. in this procedure, polypeptides with extensive hydrophobic regions (i.e., intrinsic proteins) form mixed micelles with triton x-114, and are separated from extrinsic proteins by temperature-mediated precipitation of the mix ...19846093709
genetic analysis of mutants of aspergillus nidulans blocked at an early stage of sporulation.three mutants of aspergillus nidulans, selected to have a block at an early stage of conidiation (asexual sporulation), exhibit similar pleiotropic phenotypes. each of these mutants, termed preinduction mutants, also are blocked in sexual sporulation and secrete a set of phenolic metabolites at level much higher than wild type or mutants blocked at later stages of conidiation. backcrosses of these mutants to wild type showed that the three phenotypes always cosegregated. diploids containing the ...19846094473
regulation of gene expression in aspergillus nidulans. 19846101115
a mitochondrial reading frame which may code for a second form of atpase subunit 9 in aspergillus nidulans.the nucleotide sequence of a 74 codon reading frame from the aspergillus nidulans mitochondrial genome is presented. the derived amino acid sequence displays typical features of dicyclohexylcarbodiimide (dccd) binding proteins and is 84% homologous with a mitochondrial reading frame that potentially encodes an atpase subunit 9 polypeptide in neurospora crassa. however, in a. nidulans, as in n. crassa, there is strong biochemical and genetic evidence that this subunit is in fact nuclearly-encoded ...198424177948
regulation of two alcohol dehydrogenases in aspergillus aspergillus nidulans there are two alcohol dehydrogenases. in the presence of ethanol, alcohol dehydrogenase i (ahh i) is induced and alcohol dehydrogenase ii (adh ii) is repressed. adh i and adh ii have molecular weights of 39,000 and 36,000 respectively. at least adh i is under the control of alcr, a transacting regulatory gene that is adjacent to alca (the structural gene for adh i, pateman et al. 1983). mutations in the alcr regulatory gene result in non inducibility of adh i specific mrn ...198424177792
suppressible alleles in a wide domain regulatory gene in aspergillus nidulans.the area gene of aspergillus nidulans is a one of the better studied eukaryotic wide domain regulatory genes, necessary for the expression of most structural genes involved in the utilization of a wide variety of nitrogen sources (arst and cove 1973; arst 1983). here we report the isolation and properties of area alleles suppressible by translational suppressors (roberts et al. 1979). thus we show formally that the area gene specifies a protein rather than an rna product and we show that it is p ...198424177791
temperature dependent changes in absorption and fluorescence properties of the cyanobacterium anacystis nidulans.temperature dependent changes in absorbance and fluorescence of chlorophyll a (chl a) were analyzed in membrane fragments and in a chl-protein complex reconstituted with lipids isolated from the cyanobacterium anacystis nidulans. absorbance versus temperature curves measured at 656 nm showed an inflection point at 23-24°c and at 14-16°c in the membrane fragments prepared from a. nidulans cells, grown at 39° and 25°c, respectively. temperature-induced absorbance changes measured at 680 and 696 nm ...198424458777
photochemical apparatus organization in anacystis nidulans (cyanophyceae) : effect of co(2) concentration during cell growth.anacystis nidulans cells grown under high (3%) co(2) partial pressure have greater phycocyanin to chlorophyll ratio (phc/chl) relative to cells grown under low (0.2%) co(2) tension (eley (1971) plant cell physiol 12: 311-316). absorbance difference spectrophotometry of a. nidulans thylakoid membranes in the ultraviolet (deltaa(320)) and red (deltaa(700)) regions of the spectrum reveal photosystem ii/photosystem i (psii/psi) reaction center ratio (rcii/rci) changes that parallel those of phc/chl. ...198416663387
characterization of the proton-translocating cytochrome c oxidase activity in the plasma membrane of intact anacystis nidulans spheroplasts.intact spheroplasts of the cyanobacterium (blue-green alga) anacystis nidulans oxidized various exogenous c-type cytochromes with concomitant outward proton translocation while exogenous ferricytochrome c was not reduced. the h(+)/e(-) stoichiometry was close to 1 with each of the cytochromes and did not depend on the actual rate of the oxidase reaction. observed proton ejections were abolished by the uncoupler carbonyl cyanide m-chlorophenylhydrazone. cyanide, azide, and carbon monoxide inhibit ...198416663770
anacystis nidulans demonstrates a photosystem ii cation requirement satisfied only by ca or na.anacystis nidulans exhibits a total loss of photosystem ii (psii) activity upon incubation in a nutrient medium deficient in ca(2+) and na(+) and containing a divalent cation chelator. this loss of activity is light-dependent, which corresponds to an energy requirement. likewise, ca(2+) efflux takes place only in cells incubated in light. the loss of psii activity is reversible by addition of submillimolar amounts of either ca(2+) or na(+) to the external medium but not by the addition of any ot ...198516664449
photoinhibition and reactivation of photosynthesis in the cyanobacterium anacystis nidulans.the susceptibility of photosynthesis to photoinhibition and its recovery were studied on cultures of the cyanobacterium anacystis nidulans. oxygen evolution and low temperature fluorescence kinetics were measured. upon exposure to high light a. nidulans showed a rapid decrease in oxygen evolution followed by a quasi steady state rate of photosynthesis. this quasi steady state rate decreased with increasing photon flux density of the photoinhibitory light. reactivation of photosynthesis in dim li ...198516664559
a cosmid for selecting genes by complementation in aspergillus nidulans: selection of the developmentally regulated ya locus.we constructed a 9.9-kilobase cloning vector, designated pkby2, for isolating genes by complementation of mutations in aspergillus nidulans. pkby2 contains the bacteriophage lambda cos site, to permit in vitro assembly of phage particles; a bacterial origin of replication and genes for resistance to ampicillin and chloramphenicol, to permit propagation in escherichia coli; the a. nidulans trpc(+) gene, to permit selection in aspergillus; and a unique bamhi restriction site, to permit insertion o ...198516593541
13c nmr studies of carbon metabolism in the hyphal fungus aspergillus nidulans.natural-abundance high-resolution 13c nmr spectra (linewidth, 10 hz) of the hyphal fungus aspergillus nidulans have been obtained after growth on glycolytic or gluconeogenic carbon sources. various polyols, some tricarboxylic acid-cycle intermediates and amino acids, and some phospholipids and fatty acyl compounds are present. the polyols found are mannitol, arabitol, erythritol, and glycerol. the nature of the carbon source has a pronounced effect on the pool sizes of the various polyols. all a ...19853881752
mutagenicity of trichloroethylene, trichloroethanol and chloral hydrate in aspergillus nidulans.a trichloroethylene (tce) sample, free of epoxides, has been assayed for its ability to induce gene mutations (methionine suppressors) and mitotic segregation in the mould aspergillus nidulans. no increase in the spontaneous frequency of methionine suppressors was observed when conidia of a haploid strain were plated on selective medium and exposed to tce vapours. a weak but statistically significant increase in methionine suppressors was detected, however, when conidia of cultures grown and con ...19853883153
the sterols of growth and stationary phases of aspergillus nidulans cultures.the accumulation of 4-desmethyl and 4,4-dimethyl sterols, as well as the triterpenoid beta-amyrin, was analysed during both exponential and stationary phases of aspergillus nidulans growth. throughout growth, the amount of 4-desmethyl sterol was proportional to the cellular dry weight, while the dimethyl sterols and beta-amyrin stopped accumulating after day 2. the sterols were found primarily as the free alcohol and not as fatty acid esters, the glycosides, or acyl glycosides. the amount of bet ...19853884732
paramorphogenic and genotoxic activity of triton x-100 and sodium dodecyl sulphate in aspergillus nidulans.the genotoxic activities of triton x-100 and sodium dodecyl sulphate in aspergillus nidulans were assessed in order to evaluate their relative merits as paramorphogenic agents. triton x-100 was found to be ideally suited to this purpose due to its efficient paramorphogenic effect and lack of genotoxicity. sodium dodecyl sulphate was considered unsuitable since it reduced viability and was inconsistent in its paramorphogenic action.19853885021
sexual and asexual reproduction of aspergillus nidulans in vivo. 19853887151
cloning an aspergillus nidulans developmental gene by transformation.we have developed a transformation system for aspergillus nidulans giving a frequency of transformation high enough to screen a gene bank from which we were able to isolate and clone the a. nidulans developmental gene brla by visual selection. the vector contains the selective marker argb+, and with it a frequency of transformation of 500 stable transformants/micrograms plasmid dna can regularly be achieved. the evidence suggests that transformation is by integration but spontaneous excision of ...19853891328
spontaneous ir duplications generated at mitosis in aspergillus nidulans: further evidence of a preferential site of transposed attachment.a radiation-induced translocation, t(iir----iiil), has been shown to be nonreciprocal and to have most of iir, including its terminus, attached uninverted to the terminus of iiil.--progeny with the iir segment in duplicate, obtained from crosses of t(iir----iiil) to strains with a standard genome, were unstable at mitosis; like earlier duplication strains, they suffered deletions from either duplicate segment. frequent mitotic crossing over occurred between the duplicate iir segments so that, fo ...19853891510
on the genotoxicity of the pesticides endodan and kilacar in 6 different test systems.two pesticides, the fungicide endodan (ethylene thiuram monosulphide) and the insecticide-acaricide kilacar (bis(parachlorophenyl)cyclopropyl methanol), produced or used in the neighbouring countries of bulgaria and greece were investigated in a coordinated research programme for their genotoxic effects in a variety of test systems. this included the ames test, aspergillus nidulans for mitotic segregation, in vitro human lymphocyte cell cultures for sce and chromosomal aberrations, in vivo bone ...19853892282
transformation of aspergillus niger by the amds gene of aspergillus nidulans.aspergillus niger grows poorly on acetamide as a nitrogen or carbon source and lacks sequences detectably homologous to the amds gene encoding the acetamidase of aspergillus nidulans. we have taken advantage of these observations to develop a transformation system for a. niger using the amds gene as a dominant heterologous marker for selecting transformants on the basis of acetamide utilization. transformants varied in their ability to grow on amide media and the number of integrated copies of t ...19853894007
regulation of proteinase activity in aspergillus nidulans. 19853894105
mycetoma caused by aspergillus nidulans in india.the first case of mycetoma caused by aspergillus nidulans has been described from india in a young farmer of jaisalmer situated in the thar desert of western rajasthan, india. the diagnosis was confirmed by histopathological and mycological studies.19853894683
a conductimetric method for assaying asparaginase activity in aspergillus nidulans.aspergillus nidulans asparaginase activity may be assayed conductimetrically. the method is based on the increase of conductivity which is due to the production of ammonia and/or aspartate in a reaction mixture containing a. nidulans cell-free extract and asparagine or aspartate hydroxamate. this conductivity is linear with time and enzyme concentration and it follows michaelis kinetics. conductimetric activity was not detectable in mutants lacking asparaginase activity.19853896790
involvement of a particular species of beta-tubulin (beta 3) in conidial development in aspergillus nidulans.strains of aspergillus containing the bena22 mutation are resistant to benomyl for vegetative growth but do not produce conidia. to test whether conidiation involved an additional benomyl-sensitive tubulin (i.e., was mediated by a tubulin other than the tubulins coded for by the bena locus), a collection of mutants was produced that formed conidia in the presence of benomyl, i.e., were conidiation-resistant (cr-) mutants. we analyzed the tubulins of these cr- mutants using two-dimensional gel el ...19853897246
identification and functional analysis of beta-tubulin genes by site specific integrative transformation in aspergillus nidulans.we have cloned two different beta-tubulin sequences from the filamentous fungus aspergillus nidulans. each was used in the construction of transforming plasmids that carry the pyr4 gene of neurospora crassa. we used these plasmids to transform a pyrg-strain of aspergillus to uridine prototrophy. both plasmids were shown to integrate site specifically into the homologous chromosomal sequences. we then used transformant strains in genetic crosses to demonstrate that one of the cloned beta-tubulin ...19853897247
transformation of aspergillus niger using the argb gene of aspergillus nidulans.a mutant of aspergillus niger defective in ornithine transcarbamylase function was transformed with plasmids carrying a functional copy of the argb gene of aspergillus nidulans after treatment of spheroplasts in the presence of polyethylene glycol and calcium ions. the plasmid pdg3 gave stable transformants at a frequency of 4 per microgram of input dna. southern blot analysis of dna from transformants showed that pdg3 dna had integrated into the a. niger chromosomes at a variety of locations. t ...19853902571
isolation and characterization of cold-sensitive mutations at the bena, beta-tubulin, locus of aspergillus nidulans.we have isolated large numbers of conditionally lethal beta-tubulin mutations to provide raw material for analyzing the structure and function of beta tubulin and of microtubules. we have isolated such mutations as intragenic suppressors of bena33, a heat-sensitive (hs-) beta-tubulin mutation of aspergillus nidulans. among over 2,600 revertants isolated, 126 were cold-sensitive (cs-). in 41 of 78 cs- revertants analyzed, cold sensitivity and reversion from hs- to hs+ were due to mutations linked ...19853903435
mitochondria and nuclei move by different mechanisms in aspergillus nidulans.we have examined the effects of the antimicrotubule agent benomyl and several mutations on nuclear and mitochondrial movement in germlings of the filamentous fungus aspergillus nidulans. while, as previously reported, benomyl inhibited nuclear division and movement, it did not inhibit mitochondrial movement. to test the effects of benomyl more rigorously, we germinated two benomyl super-sensitive, beta-tubulin mutants at a benomyl concentration 50-100 times greater than that required to inhibit ...19853905827
nucleotide sequence encoding the biosynthetic dehydroquinase function of the penta-functional arom locus of aspergillus nidulans.the nucleotide sequence of a 1.9 kb hindiii fragment of dna derived from the arom locus of a.nidulans and encoding the biosynthetic dehydroquinase activity has been determined. the sequences encoding the biosynthetic and catabolic dehydroquinase enzymes of a.nidulans show no detectable homology, strongly suggesting convergent evolutionary pathways. the messenger rna specified by the arom locus was detected as a 5.3 kb rna species.19853906567
the purification of urease from aspergillus nidulans.a purification procedure is described for aspergillus urease, the most important step being affinity chromatography on hydroxyurea sepharose. the enzyme exists as a single active species of mr 240,000. the pure enzyme has an activity of 670 mumol urea hydrolysed/min, has a km of 10(-3) m, an optimum ph of 8.5 and a sub-unit mr of 40,000.19853912228
the aspergillus nidulans mitochondrial genome.a brief description is provided of the overall organisation of the aspergillus nidulans mitochondrial genome, as revealed by dna sequence analysis.19853916717
molecular cloning of the 3-phosphoglycerate kinase (pgk) gene from aspergillus nidulans.the aspergillus nidulans 3-phosphoglycerate kinase gene (pgk) has been isolated from a phage lambda genomic library, using the equivalent yeast gene as a hybridization probe. the location of the pgk gene within the cloned dna has been physically mapped. the dna sequence of a small region of the putative pgk has been determined and found to code for amino acids corresponding to the n-terminal end of the pgk protein. in contrast to the yeast pgk gene the aspergillus gene contains a 57 base pair in ...19853916724
the product of the regulatory gene of the proline catabolism gene cluster of aspergillus nidulans is a positive-acting protein.eight new deletion mutations in the prn gene cluster involved in l-proline catabolism in aspergillus nidulans have been characterised and mapped. three of these are located within prna, the regulatory gene mediating proline induction, and confirm the positive nature of the action of the prna product. in addition, four prna- alleles which are phenotypically suppressible by aminoglycoside antibiotics have been identified. of these four phenotypically suppressible prna- mutations, two have been tes ...19853916725
cloning and characterization of the three enzyme structural genes qutb, qutc and qute from the quinic acid utilization gene cluster in aspergillus nidulans.heterologous dna probes from the quinic acid gene cluster (qa) in neurospora crassa (schweizer 1981) have been used to isolate the corresponding gene cluster (qut) from aspergillus nidulans cloned in a phage lambda vector. n. crassa probes for each of the three enzyme structural genes in the cluster have been used to identify the corresponding genes within the a. nidulans cloned dna. the three genes are in the same relative sequence [dehydrogenase (1), qa-3 = qutb; dehydratase (3), qa-4 = qutc; ...19853916726
gene amplification in aspergillus nidulans by transformation with vectors containing the amds gene.conidial protoplasts of an a. nidulans amds deletion strain (mh1277) have been transformed to the amds+ phenotype with a plasmid carrying the wild type gene (p3sr2). optimalisation of transformation and plating conditions now has resulted in frequencies of 300-400 transformants per microgram of dna. analysis of dna from amds+ transformants of mh1277 showed that transformation had occurred by integration of vector dna sequences into the genome. in virtually all these transformants multiple copies ...19853916728
identification of the acia gene controlled by the amda regulatory gene in aspergillus nidulans.the amda gene is one of a number of transacting regulatory genes controlling expression of the amds gene in a. nidulans. a polypeptide of approximately 42,000 molecular weight has been found to be synthesized constitutively in amda mutant strains and to be acetate inducible. a lambda clone containing a gene, called acia, coding for this polypeptide has been isolated using differential screening with cdna probes. two acetate inducible rna species have been identified by probing northern blots wit ...19853916805
dependence of nitrate utilization upon active co2 fixation in anacystis nidulans: a regulatory aspect of the interaction between photosynthetic carbon and nitrogen metabolism.specific inhibition of photosynthetic co2 fixation in anacystis nidulans cells by d,l-glyceraldehyde resulted in the simultaneous inhibition of nitrate utilization, indicating a dependence of the latter process upon the provision of co2-fixation products. this dependence was lost in cells treated with l-methionine-d,l-sulfoximine or azaserine, effective inhibitors of ammonium assimilation. in these cells, nitrate uptake could proceed at rates similar to those in control cells even if co2 fixatio ...19853919645
microinjected photoreactivating enzymes from anacystis and saccharomyces monomerize dimers in chromatin of human cells.photoreactivating enzymes (pre) from the yeast saccharomyces cerevisiae and the cyanobacterium anacystis nidulans have been injected into the cytoplasm of repair-proficient human fibroblasts in culture. after administration of photoreactivation light, pre-injected cells displayed a significantly lower level of uv-induced unscheduled dna synthesis (uds) than non-injected cells. this indicates that monomerization of the uv-induced pyrimidine dimers in the mammalian chromatin had occurred as a resu ...19853923332
inhibition of nitrate utilization by amino acids in intact anacystis nidulans an attempt to establish the nature of the ammonium-assimilation products which mediate the inhibition by ammonium of nitrate uptake in cyanobacteria, the effect of different amino acids on nitrate utilization by intact anacystis nidulans cells has been assayed. to exclude an indirect inhibition of nitrate uptake through the ammonium which the amino acids might release, the cells were pretreated with l-methionine-d,l-sulfoximine (msx), a potent inactivator of glutamine synthetase. under these ...19853929744
organization of pigment proteins in the photosystem ii complex of the cyanobacterium anacystis nidulans r2.two chlorophyll-protein complexes associated with photosystem ii (psii) of the cyanobacterium anacystis nidulans r2 have been detected. the larger of the two complexes, cpvi-1, contained a 71-kda and a 42-kda protein. the 71-kda protein was determined to be the anchor protein of the phycobilisomes (the light-harvesting complex of a. nidulans psii), since it was recognized by an antibody raised against a similar protein from another cyanobacterium. the second complex, cpvi-4, contained a previous ...19853931080
variation of a 470 000 daltons antigen complex and catalase antigen in clinical isolates of aspergillus fumigatus.antigens in ruptured mycelium of 18 aspergillus strains including 14 clinical isolates of a. fumigatus were studied by immunoelectrophoresis. one antigenic component of molecular weight 470 000 previously characterized by hydrophobic interaction chromatography and gel filtration and a second component with catalase activity were detected in all a. fumigatus isolates but in varying quantities. the 470 000 antigen complex cross-reacted with antigens in a. flavus and a. nidulans but not in a. niger ...19853934773
mycotoxins producing fungi and mycoflora of air-dust from taif, saudi arabia.using the dilution plate method, 70 species and 31 genera were collected from 20 dust samples on glucose (28 genera and 64 species) and cellulose czapek's agar (22 genera and 46 species) at 28 degrees c. the most common fungi were aspergillus niger, a. flavus, a. flavus var. columnaris, phoma glomerata, fusarium oxysporum, penicillium chrysogenum and mucor racemosus; and a. nidulans, phoma humicola, drechslera spicifera and stachybotrys chartarum on the two media, respectively. toxicity test sho ...19853935928
dna metabolism during infection of anacystis nidulans by cyanophage as-1. vi. effect of hydroxyurea and nalidixic acid on the development of cyanophage as-1.the use of the dna inhibitors hydroxyurea (hu) and nalidixic acid (nal) to elucidate patterns of dna metabolism in as-1 infected a. nidulans have led to several conclusions. first, hu and nal at concentrations of 500 and 100 micrograms/ml, respectively, inhibited dna synthesis in synchronized a. nidulans. protein and chlorophyll synthesis remained essentially unchanged as did turbidity increases. second, the complete burst size of the cyanophage as-1 was severely affected by hu and nal treatment ...19853938513
dna metabolism during infection of anacystis nidulans by cyanophage as-1. vii. uv-induced alterations of the as-1/a. nidulans lytic order to interfere specifically with either the host of phage dna metabolism and separate the effects of new phage dna synthesis from the effects of host cell breakdown and pil-dna formation, uv irradiation of either the host, a. nidulans, or intact phage as-1, prior to infection was utilized. several conclusions were reached. first, a photoreactivation system was present in uv-irradiated a. nidulans. second, the complete burst size of as-1 was severely affected by uv irradiation of cells and ...19853938514
transformation of aspergillus nidulans. 19853939985
the sub-cellular localisation and regulatory properties of pyruvate carboxylase from rhizopus arrhizus.cell-free extracts of rhizopus arrhizus contain exclusively cytosolic pyruvate carboxylase and nad-glutamate dehydrogenase, a single mitochondrial isoenzyme of nadp-isocitrate dehydrogenase, and both mitochondrial and cytosolic isoenzymes of nadp-malate dehydrogenase (decarboxylating). other enzymes examined have sub-cellular localisations similar to those characteristic of mammalian liver. purified preparations of r. arrhizus pyruvate carboxylase are subject to partial regulatory inhibition by ...19853971971
mutagenicity of three agricultural soils.a chemical and biological testing protocol was employed to evaluate the mutagenic potential of the organic compounds extracted from three agricultural soils. the analytical procedures used included bioassays with salmonella typhimurium and aspergillus nidulans for the detection of point mutations and a gas chromatography/mass spectrometry/computer system to identify major organic constituents. the extracts of all three soils exhibited mutagenic response in the bioassays. at a dose level of 1000 ...19853983630
the mitochondrial genome of the fission yeast schizosaccharomyces pombe. the cytochrome b gene has an intron closely related to the first two introns in the saccharomyces cerevisiae cox1 gene.the dna sequence of the cob region of the schizosaccharomyces pombe mitochondrial dna has been determined. the cytochrome b structural gene is interrupted by an intron of 2526 base-pairs, which has an open reading frame of 2421 base-pairs in phase with the upstream exon. the position of the intron differs from those found in the cob genes of saccharomyces cerevisiae, aspergillus nidulans or neurospora crassa. the sch. pombe cob intron has the potential of assuming an rna secondary structure almo ...19854046021
heterogeneity of 5s rna in fungal ribosomes.neurospora crassa has at least seven types of 5s rna genes (alpha, beta, gamma, epsilon, delta, zeta, and eta) with different coding regions. a high resolution gel electrophoresis system was developed to separate minor 5s rna's from the major 5s rna (alpha). a study of several neurospora crassa strains, four other species in the genus neurospora, members of two closely related genera, and three distantly related genera demonstrated that 5s rna heterogeneity is common among fungi. in addition, di ...19852579431
probing fungal mitochondrial evolution with trna.sequence data are now available for almost the entire complement of mitochondrial rrnas from five fungi: schizosaccharomyces pombe, saccharomyces cerevisiae, toropulis glabrata, aspergillus nidulans and neurospora crassa. analysis of these data show that the five mitochondria can be related to a common ancestor. the unusually high similarity between some s. pombe mt trnas may be due to a process similar to gene conversion. using the number of differences between trna pairs as a measure of the ev ...19852417640
nitrogen catabolite repression in yeasts and filamentous fungi. 19852869649
cloning and characterization of the rdna repeat unit of podospora anserina.dna coding for ribosomal rna in podospora anserina has been cloned and was found as a tandemly repeated 8.3 kb sequence. the cloned rdna was characterized by restriction endonuclease mapping. the location of 5.8s, 18s and 28s rrna coding regions was established by dna-rna hybridization and s1 nuclease mapping. the organization of p. anserina rrna genes is similar to that of neurospora crassa and aspergillus nidulans. the rdna unit does not contain the sequence coding for 5s rna.19852987647
cloning of phosphoenolpyruvate carboxylase gene from a cyanobacterium, anacystis nidulans, in escherichia coli.the phosphoenolpyruvate carboxylase gene (ppc) from anacystis nidulans, a cyanobacterium (blue-green alga), was cloned in escherichia coli. chromosomal dna of a. nidulans was partially digested with sau3ai, and the obtained dna fragments were ligated in the bamhi site of pbr322. the hybrid plasmids were first transformed into e. coli k802 (hsdr-, hsdm+) to obtain the gene bank of a. nidulans. the bank consisted of about 12,000 clones. these hybrid plasmids were then transformed into e. coli pcr1 ...19852989256
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