| isolation and characterization of the positively acting regulatory gene quta from aspergillus nidulans. | the positively acting regulator gene quta from aspergillus nidulans has been identified and located within a cluster of quinic acid utilisation (qut) genes isolated within a recombinant phage lambda (lambda q1). the dna sequence of the quta gene reveals a single uninterrupted reading frame coding for a protein of mw 90.416 kd. the quta protein sequence has a protein motif in the form of a putative "dna finger" that shows strong homology to other such motifs in the gal4, ppr1, argrii, lac9 and qa ... | 1987 | 3313276 |
| 13c-nmr analysis of aspergillus mutants disturbed in pyruvate metabolism. | the metabolic consequences of two defects in pyruvate metabolism of the hyphal fungus aspergillus nidulans have been investigated by natural abundance 13c-nmr spectroscopy. a pyruvate dehydrogenase complex (pdh) mutant, grown on acetate, accumulates alanine upon starvation which is derived from mannitol reserves. the l-alanine level increases further upon incubation with the non-permissive substrate d-glucose. l-glutamate is absent from these spectra as it is required both for the transamination ... | 1987 | 3315006 |
| [modern electron microscopy at cellular and macromolecular levels. strategies for preparation, imaging and image interpretation]. | conventional electron microscopy has significantly contributed to the understanding of structure-function relationships in living systems on cellular and macromolecular levels. new approaches and strategies will provide further insight into the organization of life. these new developments include cryopreparation and imaging techniques, x-ray microanalysis on frozen samples, electron energy loss spectroscopy, electron spectroscopic imaging, electron microscopic immunocytochemistry, preparation an ... | 1987 | 3317069 |
| cloning and characterization of the isopenicillin n synthetase gene mediating the formation of the beta-lactam ring in aspergillus nidulans. | genomic clones containing an aspergillus nidulans isopenicillin n synthetase (ipns) gene have been identified by heterologous hybridization with a cephalosporium acremonium dna probe. the open reading frame encodes a 331 amino acid polypeptide with extensive homology with the genes of other beta-lactam-producing fungi. the gene product has been overexpressed in escherichia coli and shown to have activity of ipns. this represents the first evidence at the molecular level that the biosynthesis of ... | 1987 | 3319778 |
| the unique histone h2a gene of aspergillus nidulans contains three introns. | the histone h2a gene of the filamentous fungus aspergillus nidulans has been cloned and sequenced. there is a single h2a gene in the genome of a. nidulans, and it contains three introns. the introns are 51 nucleotides (nt), 56 nt and 50 nt in length and split codons for amino acids (aa) 18, 48 and 116 of the predicted protein. the transcriptional start and termination points have been determined using an s1 nuclease protection assay. the predicted protein is 132 aa residues in length and surpris ... | 1987 | 3319784 |
| transformation of aspergillus nidulans with the hygromycin-resistance gene, hph. | aspergillus nidulans strain g191 was transformed to hygromycin resistance using plasmid pdh25, which contains the bacterial hygromycin b phosphotransferase gene (hph) fused to promoter elements of the a. nidulans trpc gene. southern hybridizations of transformants revealed multiple, integrated copies of the vector. a pleiotropic effect conferring increased hygromycin b sensitivity was found to be associated with the a. nidulans pyrg89 allele. plasmid pdh25 features a clai site immediately preced ... | 1987 | 3322945 |
| emericella nidulans in a maxillary sinus fungal mass. | sexual reproductive stages of fungi are very rarely found within mammalian tissues. we report here coexistence of cleistothecia associated with emericella nidulans and its conidial state, aspergillus nidulans, in a fungal mass which developed in a maxillary sinus. | 1987 | 3323452 |
| monoclonal antibody probes for the niad specified subunit in the nadph-nitrate reductase from aspergillus nidulans. | in aspergillus nidulans, the nitrate assimilatory pathway is regulated by a variety of agents, one being the autogenous enzyme nitrate reductase. a major subunit of the enzyme which is specified by the niad structural gene and is implicated in autogenous control exhibits both nitrate inducible diaphorase activity and ammonium repression. the former was used to test the extent to which alterations in the niad specified protomer might affect its formation in selected niad point and deletion mutant ... | 1987 | 3323853 |
| on the mechanism of mitotic segregation induction in aspergillus nidulans by benzene hydroxy metabolites. | the principal hydroxy-metabolites of benzene--hydroquinone, catechol and phenol--were assayed in tests for mitotic segregation induction in aspergillus nidulans diploid strain 19. hydroquinone was the most effective chemical, increasing the frequency of mitotic segregants up to 10-fold at 1-3 mm. catechol was similarly active at 10-20 mm and phenol was weakly positive at 15 mm. genetic characterization of induced abnormal segregating colonies by replating and complementary assays with haploid st ... | 1987 | 3325750 |
| aspergillus nidulans 5s rrna genes and pseudogenes. | the sequence of four aspergillus nidulans 5s rrna genes and of two pseudogenes has been determined. a conserved sequence about 100 bp upstream of the 5s rrna coding sequences has been found in three genes and one pseudogene. the two pseudogenes correspond to the 5' half of the 5s rrna coding sequence and their 3' flanking sequences which are not homologous to 5s rrna are strongly conserved. | 1986 | 3327606 |
| genetic and molecular characterization of argb+ transformants of aspergillus nidulans. | thirty-three argb- to argb+ transformants of aspergillus nidulans have been subjected to genetic and molecular analysis. two showed high levels of mitotic instability although it is suggested that this is a consequence of heterokaryosis rather than instability of the transformation event. most transformants resulted from the integration of the transforming dna in tandem with the chromosomal argb locus. the maximum number of inserted sequences was two, to generate three copies of the argb locus. ... | 1986 | 3327613 |
| mitotic recombination in stable and unstable chromosome iii disomics of aspergillus nidulans. | approximately 2% of the haploid breakdown sectors of heterozygous chromosome iii disomics of aspergillus nidulans are the result of recombination between the homologous chromosomes. the exchanges are concentrated between the two mutations spanning the centromere. comparisons are made between disomics hemizygous for the sodiii a1 mutation (upshall et al. 1979) which are stable when grown at 37 degrees c, and disomics carrying the wild type allele of the sodiii a1 locus, which are unstable under a ... | 1986 | 3327614 |
| chemical and physical agents assayed in tests for mitotic intergenic and intragenic recombination in aspergillus nidulans diploid strains. | data from aspergillus nidulans mitotic recombination assays published over the period 1960-1986 are briefly reviewed. the results of the testing of 104 chemical agents and three physical agents are summarized. a tentative comparison of the performance of recombinational, mutational and aneuploidy assays in a. nidulans suggests that the former can effectively detect dna-damaging agents which either induce true genetic recombination (intergenic or intragenic crossing-over) or mimic it by inducing ... | 1987 | 3328037 |
| cloning, mapping and molecular analysis of the pyrg (orotidine-5'-phosphate decarboxylase) gene of aspergillus nidulans. | we have modified the transformation procedures of ballance et al. [biochem. biophys. res. commun. 112 (1983) 284-289] to give increased rates of transformation in aspergillus nidulans. with the modified procedures we have been able to complement pyrg89, a mutation in the orotidine-5'-phosphate decarboxylase gene of a. nidulans, by transformation with a library of wild-type (wt) sequences in pbr329. we have recovered, by marker rescue from one such transformant, a plasmid (pjr15) that carries an ... | 1987 | 3328733 |
| behaviour of recombinant plasmids in aspergillus nidulans: structure and stability. | a pyrg- aspergillus strain was transformed with plasmid pdjb-1, derived from pbr325 by insertion of the neurospora crassa pyr4 gene (orotidine 5'-phosphate carboxylase), giving mitotically unstable transformants. aspergillus dna which acted as an "autonomously replicating sequence" (ars) in yeast was inserted into pdjb-1 and the resulting construct, pdjb12.1, gave mitotically stable transformants when introduced into aspergillus. transformants obtained with pdjb-1 and pdjb12.1 gave few pyr- prog ... | 1986 | 3329034 |
| heat shock phenomena in aspergillus nidulans. i. the effect of heat on mycelial protein synthesis. | heat shock was found to induce characteristic changes in the pattern of protein synthesis in aspergillus nidulans as analysed by sds-polyacrylamide gel electrophoresis. six to seven new bands were found to show increased incorporation to 35s-methionine at 43 degrees c compared to 37 degrees c, the standard temperature for this organism. the heat shock response of five different strains of a. nidulans was examined. this comparative study showed that these strains (haploids and diploids) show exac ... | 1986 | 3329035 |
| induction and isolation of mutants in fungi at low mutagen doses. | since the yield of mutants per surviving cell increases in general with increasing dose of mutagen, it has often been concluded in the literature that it is the most efficient to apply high mutagen doses so that most spores are killed. as high doses of mutagen produce chromosome rearrangements and unnoticed mutations which disturb the genetic background, the relationship between mutant frequency and survival was analyzed with aspergillus nidulans as a model. it is shown that for different types ... | 1987 | 3329055 |
| microheterogeneity in aspergillus nidulans 5s rrna genes. | we have determined the sequence of 4 aspergillus nidulans 5s rrna genes and compared it with 4 previously established sequences. no extensive homologies are found in 5' flanking sequences, but in the 3' flanks of two genes and two pseudogenes similar sequences are observed. in the coding sequences differences occur in 7 positions. two 5s rrna genes which are found in one plasmid 1.1 kb apart are located in opposite orientations. | 1987 | 3329974 |
| suppressors suac109 and suaa101 of aspergillus nidulans alter the ribosomal phenotype in vitro. | a new homologous, cell-free system for protein synthesis has been devised for use with ribosomes and elongation factors from aspergillus nidulans. ribosome preparations from strains with either the suaa101 or suac109 mutations have a higher misreading ratio (non-cognate:cognate amino acid incorporation) in the presence of hygromycin than controls. they can be classed as fidelity mutants. these results also prove that the mutations must be in genes coding for ribosomal proteins or enzymes which m ... | 1987 | 3331121 |
| cloning and molecular analysis of the ornithine carbamoyl transferase gene of aspergillus niger. | we have cloned the gene encoding ornithine carbamoyl transferase (octase) from aspergillus niger. the structure and complete nucleotide sequence of this gene have been determined. the gene encodes an mrna of 1.3 kb. the transcription unit contains an open reading frame of 1110 nucleotides (nt) which shows strong homology to the octase of aspergillus nidulans along most of its length. the n terminus, which shows little or no homology to other octases, is highly basic and is probably involved in m ... | 1987 | 3443301 |
| the subunit i of the respiratory-chain nadh dehydrogenase from cephalosporium acremonium: the evolution of a mitochondrial gene. | a cephalosporium acremonium mitochondrial gene equivalent to human urf1 has been identified. the primary structure of the protein is highly homologous to its human (39%) and a. nidulans (66%) counterparts. hydrophobicity profiles and predicted secondary structures are also very similar suggesting that this gene codes for the subunit i of the respiratory-chain nadh dehydrogenase. the nucleotide sequence of the gene, 70% homologous to the a. nidulans one, presents a high at content (72%) and this ... | 1986 | 3447737 |
| the watermelon mitochondrial urf-1 gene: evidence for a complex structure. | we have cloned and sequenced a fragment of watermelon mitochondrial dna (mtdna) which contains a gene homologous to mitochondrial urf-1 (unidentified reading frame-1) of vertebrates, drosophila yakuba and aspergillus nidulans. urf-1 is thought to encode a component of the respiratory chain nadh dehydrogenase. two coding regions in the watermelon gene are separated by approximately 1,450 bp of untranslatable dna. these two exons encode the central portions of urf-1, and are highly conserved. we p ... | 1986 | 3447741 |
| development of a homologous transformation system for aspergillus niger based on the pyrg gene. | the development of a homologous transformation system for aspergillus niger is described. the system is based on the use of an orotidine-5'-phosphate decarboxylase deficient mutant (pyrg) and a vector, pab4-1, which contains the functional a. niger pyrg gene as a selection marker. transformation of the a. niger pyrg mutant with pab4-1 resulted in the appearance of stable pyr+ transformants at a frequency of 40 transformants per microgram of dna. in 90% of these transformants integration had occu ... | 1987 | 3472035 |
| differential riboflavin deposition in white and variegated white mutants of drosophila hydei. | riboflavin deposition in organs of drosophila hydei was studied by means of a growth test using a riboflavin-deficient strain of the fungus aspergillus nidulans. in wild-type animals, riboflavin is deposited in malpighian tubules (mt) and testes but not in adult eyes. certain white (w) mutants do not contain riboflavin, whereas intermediately colored w mutants contain minor amounts of the substance. riboflavin-containing mt cells contain special globules that can be fixed and stained with the re ... | 1987 | 3502968 |
| systems and results of tests for chemical induction of mitotic malsegregation and aneuploidy in aspergillus nidulans. | in aspergillus several types of test systems have been developed for detection of chemicals which induce aneuploidy and/or malsegregation of chromosomes. results from 23 papers were reviewed in which numerical data for 42 chemicals had been reported. the test systems fall into two groups. one group includes all purely genetic tests that detect euploid mitotic segregants from heterozygous diploids and identify these either as products of malsegregation of chromosomes or as products of crossing-ov ... | 1986 | 3510377 |
| pyruvate carboxylase from saccharomyces cerevisiae. quaternary structure, effects of allosteric ligands and binding of avidin. | the quaternary structure of pyruvate carboxylase purified from saccharomyces cerevisiae was investigated by electron microscopic examination of negatively stained samples. in the most frequently observed projection form four intensity maxima were arranged at the corners of a rhombus; a cleft along the longitudinal axis of individual protomers could often be discerned. the observation of occasional triangular and dual-intensity projections and the interconversion of all three projection forms in ... | 1986 | 3514213 |
| the isolation and nucleotide sequence of the complex arom locus of aspergillus nidulans. | the arom locus of a. nidulans, which governs five consecutive steps in pre-chorismate aromatic amino acid biosynthesis, has been cloned in a bacteriophage vector. the nucleotide sequence of the locus reveals a single, open reading-frame of 4,812 base-pairs, apparently without introns. an internal segment of the a. nidulans arom sequence has extensive homology with the e. coli aroa gene that encodes the 5-enolpyruvylshikimate 3-phosphate synthase. | 1986 | 3515316 |
| the fatty acid composition of the conidia and mycelia of the fungus aspergillus nidulans. | the total fatty acids were characterized from conidia, exponential phase, and stationary phase aspergillus nidulans. several quantitative and qualitative variations were observed. most notable was the approximately 15-fold increase in linolenate observed during the 1st day of incubation and its subsequent total disappearance by day 4. | 1986 | 3516353 |
| mitotic crossing over in chromosome i disomics of aspergillus nidulans. | the frequency and pattern of homologous recombination in chromosome i disomics of aspergillus nidulans is presented. approximately 6% of randomly selected haploid breakdown sectors are recombinant. most of these arise from double exchange events, one of which is located in the centromere region, the other distal on the left arm. other marked regions are rarely involved in a recombination event. reciprocal genotypes arise in approximately equal frequencies indicating that exchange results in reci ... | 1986 | 3520237 |
| tests which distinguish induced crossing-over and aneuploidy from secondary segregation in aspergillus treated with chloral hydrate or gamma-rays. | a system of tests with the ascomycete aspergillus nidulans was devised that can detect 3 primary effects of genotoxic agents: (1) increases in mitotic crossing-over; (2) induced aneuploidy; and (3) clastogenic effects which cause chromosomal imbalance. conidia of a new diploid tester strain, heterozygous for 4 recessive markers which alter conidial color, are treated and plated onto nonselective media. in cases of induced crossing-over, large color segments are found in normal green colonies, fr ... | 1986 | 3520302 |
| nucleotide sequence of the triosephosphate isomerase gene from aspergillus nidulans: implications for a differential loss of introns. | a functional cdna from aspergillus nidulans encoding triosephosphate isomerase (tpi) was isolated by its ability to complement a tpi1 mutation in saccharomyces cerevisiae. this cdna was used to obtain the corresponding gene, tpia. alignment of the cdna and genomic dna nucleotide sequences indicated that tpia contains five introns. the intron positions in the tpia gene were compared with those in the tpi genes of human, chicken, and maize. one intron is present at an identical position in all fou ... | 1986 | 3521890 |
| genetic analysis of dna repair in aspergillus: evidence for different types of mms-sensitive hyperrec mutants. | to identify genes which affect dna repair and possibly recombination in aspergillus nidulans, mutants hypersensitive to methyl methanesulphonate (mms) were induced with ultraviolet light (uv) or gamma-rays. about half of them contained associated translocations and many were hypersensitive to uv and/or defective in meiosis. two are alleles of the known uvsb gene while most others define new genes. in addition, among available uvs mutants many were found to be mms-sensitive. some of the various u ... | 1986 | 3523224 |
| genetic and functional analysis of beta tubulin in aspergillus nidulans. | | 1986 | 3524367 |
| functional assembly in vitro of phycobilisomes with isolated photosystem ii particles of eukaryotic chloroplasts. | phycobiliproteins obtained by dissociation of phycobilisomes were reassociated in vitro with intact thylakoids or isolated photosystems i and ii preparations obtained from cyanophytes (prokaryotes) or green algae (eukaryotes) to form bound phycobilisome complexes. energy transfer from fremyella diplosiphon phycobiliproteins to chlorophyll a of reaction centers i and ii was measured in: complexes containing intact thylakoids of the cyanophytes f. diplosiphon or anacystis nidulans and the eukaryot ... | 1986 | 3528156 |
| a comparative study on selected chemical carcinogens for chromosome malsegregation, mitotic crossing-over and forward mutation induction in aspergillus nidulans. | 10 "false negative" chemical carcinogens, i.e. ineffective in bacterial mutagenicity assays, were thoroughly investigated for their genotoxic activity in the mould aspergillus nidulans. forward mutations (methionine suppressors), mitotic crossing-over and chromosome malsegregation were the end-points scored. positive results were obtained in tests for the induction of mitotic segregation with benzene, ethylenethiourea and urethane, which increased the frequency of abnormal presumptive aneuploid ... | 1986 | 3531838 |
| transcription and processing signals in the 3-phosphoglycerate kinase (pgk) gene from aspergillus nidulans. | the 3-phosphoglycerate kinase gene from aspergillus nidulans contains two 57-bp introns and codes for a 421-amino acid (aa) protein with considerable homology to the saccharomyces cerevisiae (68%) and mammalian (64%) proteins. almost total conservation is found in aspergillus of residues thought to be important to the structure and function of the yeast enzyme, and the introns fall between coding sequences for postulated structures in the n-domain. the strong codon preference found is more simil ... | 1986 | 3533726 |
| characterization of aspergillus nidulans mutants in carbon metabolism isolated after d-galacturonate enrichment. | a selective method for the isolation of aspergillus nidulans mutants defective in the pyruvate dehydrogenase complex was devised. the essential steps in the procedure were a mutagenic treatment of conidia with x-rays to about 50% survival, followed by filtration enrichment in minimal medium with d-galacturonate as sole carbon source, and rescue on complete medium with acetate. the mutants thus isolated were phenotypically characterized on the basis of growth tests, and different genotypes were a ... | 1986 | 3534135 |
| osmotic adjustment in the filamentous fungus aspergillus nidulans. | aspergillus nidulans was shown to be xerotolerant, with optimal radial growth on basal medium amended with 0.5 m nacl (osmotic potential [psi s] of medium, -3 mpa), 50% optimal growth on medium amended with 1.6 m nacl (psi s of medium, -8.7 mpa), and little growth on medium amended with 3.4 m nacl (psi s of medium, -21 mpa). the intracellular content of soluble carbohydrates and of selected cations was measured after growth on basal medium, on this medium osmotically amended with nacl, kcl, gluc ... | 1986 | 3536874 |
| isolation of mip (microtubule-interacting protein) mutations of aspergillus nidulans. | we identified four mutations in two previously undescribed loci involved in microtubule function in aspergillus nidulans as extragenic suppressors of bena33, a heat-sensitive beta-tubulin mutation. three of the four mutations map to a locus closely linked to ribob on linkage group viii; we designated this locus mipa (for microtubule-interacting protein). we were not able to map the remaining suppressor because of chromosomal rearrangements. however, since it recombines with ribob at a significan ... | 1986 | 3537728 |
| saccharomyces cerevisiae centromere cen11 does not induce chromosome instability when integrated into the aspergillus nidulans genome. | we constructed aspergillus nidulans transformation plasmids containing the a. nidulans argb+ gene and either containing or lacking centromeric dna from saccharomyces cerevisiae chromosome xi (cen11). the plasmids transformed an argb aspergillus strain to arginine independence at indistinguishable frequencies. stable haploid transformants were obtained with both plasmids, and strains were identified in which the plasmids had integrated into chromosome iii by homologous recombination at the argb l ... | 1986 | 3540597 |
| detection of point-mutation mutagens in aspergillus nidulans: comparison of methionine suppressors and arginine resistance induction by fungicides. | in the present study we describe the effect of 4 fungicides on the induction of point mutations in strains bia1 methg1 (induction of methionine suppressors) and 118 (induction of arginine resistance) of aspergillus nidulans. captan, which was used as a known mutagen, daconil 2787 and dithane m-45 were effective in inducing these mutations, whereas the fungicide cercobin caused no significant increase in the induction frequency of the point mutations selected. actually, a decrease in the frequenc ... | 1987 | 3540650 |
| genetic analysis of aspergillus nidulans amds+ transformants. | to correlate the genetic background of the aspergillus nidulans amds deletion strain mh1277 with the integrational behaviour of transforming vectors, classical genetic methods were used to construct amds- strains in which whole chromosomes had been exchanged with those of a master strain. progeny strains were transformed to the amds+ phenotype with vector p3sr2. from southern analysis it was concluded that transformants from all constructions contained tandemly repeated, multiple copy inserts of ... | 1986 | 3543620 |
| intracellular localization of aspergillus nidulans ornithine carbamoyltransferase in native host cells and in saccharomyces cerevisiae cells harbouring its cloned structural gene. | differential centrifugation of the aspergillus nidulans cell lysate shows that ornithine carbamoyltransferase (ec 2.1.3.3) appears mainly in the particulate (organellar) fraction. the enzyme was located to the mitochondria by co-sedimentation with cytochrome oxidase in isopycnic density gradient and by cytochemical-electron microscopic means. arginase (ec 3.5.3.1) and ornithine delta-aminotransferase (e.c. 2.6.1.13) were found to reside in cytosol. the release of ornithine carbamoyltransferase f ... | 1986 | 3544621 |
| primary structure of mucor miehei aspartyl protease: evidence for a zymogen intermediate. | the gene encoding the aspartyl protease of the filamentous fungus mucor miehei has been cloned in escherichia coli and the dna sequenced. the deduced primary translation product contains an n-terminal region of 69 amino acid (aa) residues not present in the mature protein. by analogy to the evolutionarily related mammalian gastric aspartyl proteases it is inferred that the primary secreted product is a zymogen containing a 47-aa propeptide. this propeptide is presumably removed in the later step ... | 1986 | 3549462 |
| a system for the analysis of expression signals in aspergillus. | to analyse gene expression signals in aspergillus we have constructed a set of integration vectors each of which contains in front of the escherichia coli 'lacz gene a unique bamhi site in one of the three possible translational reading frames and the a. nidulans argb gene as a selection marker. the vectors allow in-phase translational fusion of any gene to 'lacz. after transformation of an a. nidulans argb strain, the vectors integrate with a high percentage at the argb locus of the genome, as ... | 1986 | 3549463 |
| position-dependent and -independent mechanisms regulate cell-specific expression of the spoc1 gene cluster of aspergillus nidulans. | many genes that are expressed specifically in the differentiating asexual spores (conidia) of aspergillus nidulans are organized into clusters. we investigated the effects of altered chromosomal position on expression of a gene from the conidiation-specific spoc1 gene cluster. the gene became deregulated when integrated at nonhomologous chromosomal sites, in that transcript levels were elevated in vegetative cells (hyphae) and variably altered in conidia. we also investigated the effects on expr ... | 1987 | 3550422 |
| the amds gene of aspergillus nidulans: control by multiple regulatory signals. | | 1986 | 3551935 |
| effect of the bnca gene on the instability of aspergillus nidulans. | | 1986 | 3552882 |
| synthesis and biocidal activity of zn(ii) complexes of some 2,2'-substituted diphenylamines. | binary as well as ternary complexes of zn(ii) with diphenylamine-2,2'-dicarboxylic acid (dpdc), diphenylamine-2-amino-2'-carboxylic acid (dpac), diphenylamine-2-hydroxy-2'-carboxylic acid (dphc), diphenylamine-2-mercapto-2'-carboxylic acid (dpmc), and n-(2-pyridino) anthranilic acid (npa) have been synthesized and characterized by their elemental analysis, ir spectral data, and molar conductance measurements. antimicrobial activity of these ligands and their respective zn(ii) complexes have been ... | 1987 | 3553430 |
| mms sensitivity of all amino acid-requiring mutants in aspergillus and its suppression by mutations in a single gene. | all available amino acid-requiring mutants of aspergillus nidulans were found to be hypersensitive to mms (methyl methanesulfonate) to various degrees. on mms media, secondary mutations could be selected which suppress this mms sensitivity but do not affect the requirement. many such mutations were analyzed and found to be alleles of one gene, smsa (= suppressor of mms sensitivity), which mapped distal on the right arm of chromosome v. this gene is more likely to be involved in general regulatio ... | 1987 | 3556318 |
| biosynthesis of thiamin. different biosynthetic routes of the thiazole moiety of thiamin in aerobic organisms and anaerobic organisms. | the nitrogen atom of glycine was incorporated into the thiazole moiety of thiamin in the aerobic microorganisms bacillus subtilis, pseudomonas putida, saccharomyces cerevisiae, mucor racemosus, neurospora crassa, and emericella nidulans. it was not incorporated in the case of the facultative anaerobic microorganisms escherichia coli and enterobacter aerogenes, which, however, did incorporate the nitrogen atom of tyrosine. these results show that aerobic microorganisms and facultative anaerobic m ... | 1987 | 3566774 |
| use of alpha- and beta-tubulin mutants for the study of spontaneous and induced chromosomal mis-distribution in aspergillus nidulans. | the effect of two different mutations, one involving an alpha-tubulin (tuba) and the other a beta-tubulin (bena33) gene, on somatic segregation has been investigated in diploid strains of a. nidulans. both mutations, particularly bena33, increase the level of spontaneous chromosomal mis-distribution (cmd) phenomena, without affecting the frequency of crossing-over. the employment of homozygous strains for each of the two mutations in sensitivity tests toward various chemicals, allowed the clear ... | 1987 | 3574324 |
| the nature of l8 and l8s8 forms of ribulose bisphosphate carboxylase/oxygenase from chromatium vinosum. | l8 and l8s8 forms of ribulose bisphosphate carboxylase/oxygenase (rubisco) have been prepared from chromatium vinosum by the extremely mild method of centrifugal fractionation. only the l8s8 form is detectable in crude extracts of this organism. both forms show immunological identify in double diffusion studies using antibody to l subunits of the l8s8 form. l subunits from both l8 and l8s8 enzymes are identical by the criteria of peptides observed after limited proteolysis and n-terminal sequenc ... | 1987 | 3579306 |
| genotoxicity of hexachlorobenzene and other chlorinated benzenes. | hexachlorobenzene (hcb) and other chlorinated benzenes have had only limited mutagenicity evaluation but tests have shown a general lack of evidence for mutagenicity. bacterial reverse mutation studies have been typically negative and only a few studies on cultured mammalian cells have been published. recent reports indicate that hcb does not induce sister chromatid exchange or dna-strand breakage in vitro. a single report of hcb-induced reverse mutation in yeast is suspect due to the failure to ... | 1986 | 3596730 |
| a case of guttural pouch mycosis in a horse. | a case of guttural pouch mycosis in an 11-year-old horse is described. the fungus isolated was identified as emericella nidulans. housing under bad hygienic conditions without ventilation for three years might have been a predisposing factor. | 1986 | 3725585 |
| 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 ... | 1985 | 3881752 |
| 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 ... | 1985 | 3883153 |
| 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 ... | 1985 | 3884732 |
| 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. | 1985 | 3885021 |
| sexual and asexual reproduction of aspergillus nidulans in vivo. | | 1985 | 3887151 |
| 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 ... | 1985 | 3891328 |
| 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 ... | 1985 | 3891510 |
| 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 ... | 1985 | 3892282 |
| 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 ... | 1985 | 3894007 |
| regulation of proteinase activity in aspergillus nidulans. | | 1985 | 3894105 |
| 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. | 1985 | 3894683 |
| 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. | 1985 | 3896790 |
| 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 ... | 1985 | 3897246 |
| 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 ... | 1985 | 3897247 |
| 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 ... | 1985 | 3902571 |
| 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 ... | 1985 | 3903435 |
| 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 ... | 1985 | 3905827 |
| 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. | 1985 | 3906567 |
| 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. | 1985 | 3912228 |
| 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. | 1985 | 3916717 |
| 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 ... | 1985 | 3916724 |
| 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 ... | 1985 | 3916725 |
| 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; ... | 1985 | 3916726 |
| 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 ... | 1985 | 3916728 |
| 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 ... | 1985 | 3916805 |
| 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 ... | 1985 | 3919645 |
| 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 ... | 1985 | 3923332 |
| inhibition of nitrate utilization by amino acids in intact anacystis nidulans cells. | in 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 ... | 1985 | 3929744 |
| 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 ... | 1985 | 3931080 |
| 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 ... | 1985 | 3934773 |
| 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 ... | 1985 | 3935928 |
| 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 ... | 1985 | 3938513 |
| dna metabolism during infection of anacystis nidulans by cyanophage as-1. vii. uv-induced alterations of the as-1/a. nidulans lytic cycle. | in 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 ... | 1985 | 3938514 |
| transformation of aspergillus nidulans. | | 1985 | 3939985 |
| 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 ... | 1985 | 3971971 |
| 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 ... | 1985 | 3983630 |
| 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 ... | 1985 | 4046021 |
| the genetic analysis of regulation of amidase synthesis in aspergillus nidulans. ii. mutants resistant to fluoroacetamide. | | 1970 | 4097637 |
| the use of amides as nitrogen sources by aspergillus nidulans. | | 1970 | 4102613 |
| ultrastructure of dormant and germinating conidia of aspergillus nidulans. | | 1972 | 4110693 |
| the effects of griseofulvin on mitosis in aspergillus nidulans. | | 1972 | 4113458 |
| osteomyelitis and pneumonia in a boy with chronic granulomatous disease of childhood caused by a mutant strain of aspergillus nidulans. | | 1974 | 4131011 |
| cytochemical detection of hydrolases in fungus cells. 3. aryl sulfatase. | | 1974 | 4132629 |
| localization of free sulphydryl groups by ferricyanide reduction in developing conidiophores of aspergillus nidulans. | | 1974 | 4134662 |
| repression of enzymes of nitrogen catabolism by methylammonium and caesium chloride in strains of aspergillus nidulans insensitive to ammonium repression. | | 1974 | 4138442 |