PMID(sorted ascending)
internal structure of a mitochondrial intron of aspergillus nidulans.the intron of the mitochondrial apocytochrome b gene, coba, of aspergillus nidulans has been subjected to sequence analysis. it contains an open reading frame of 957 base pairs contiguous with the preceding exon. regions of the translated open reading frames of coba and the third intron of the cob gene in yeast show high amino acid homology. comparison of the coba intron with this and other yeast introns indicates that coba codes for a maturase protein that splices out the intron encoding it and ...19826755468
making ends meet: a model for rna splicing in fungal mitochondria.on the basis of available nucleotide sequence and genetic data; we present a model for rna splicing in fungal mitochondria. seven intron rnas of two fungal species can form identical secondary structures, involving four conserved sequences, which bring the ends of each intron together and allow an internal guide rna sequence to pair with exon bases adjacent to the splice junctions. the splicing sites are thus aligned precisely within a conserved structure, which we suggest could present specific ...19826757759
a cis-dominant mutation in aspergillus nidulans affecting the expression of the amds gene in the presence of mutations in the unlinked gene, amda.a mutant producing very high levels of the acetamidase enzyme encoded by the amds gene has been isolated in a strain containing the amda7 mutation, which itself causes high levels of this enzyme. genetic analysis has shown that this mutation, designated amdi66, is adjacent to the amds gene and is cis-dominant in its effect. the amdi66 mutation has little effect on amds expression when present in strains not containing the amda7 mutation. two other amda mutations investigated also interact with t ...19826759305
studies on air-borne fungi at qena. iii. thermophilic fungi. 19826759940
meiosis in aspergillus nidulans: another example for lacking synaptonemal complexes in the absence of crossover interference. 19826761318
a near terminal pericentric inversion leads to nitrogen metabolite derepression in aspergillus nidulans.the mutation xprd-1, previously shown to be an allele of the area gene and to lead to nitrogen metabolite derepression in aspergillus nidulans, is shown to be associated with a near terminal pericentric inversion in linkage group iii. the left arm break-point is between the adi and sc genes, and the right arm break-point is between the ornc and area genes but just centromere proximal to area. in crosses of xprd-1 strains to inversion-free strains one class of duplication-deficiency progeny is re ...19826761550
in vitro mutational studies with trifluralin and trifluorotoluene derivatives. 19826763485
modification of chromosome instability in aspergillus nidulans.strains of aspergillus nidulans with a chromosome segment in duplicate show instability at mitosis; their colonies produce faster-growing sectors which arise from nuclei with spontaneous deletions in either duplicate segment. in an attempt to probe the deletion process, the effects of mutations causing sensitivity to uv treatment, and those of manganous ions, have been studied in strains carrying either dp(i,ii) or dp(iii,viii). for comparison, the effects of mn2+ on balanced and unbalanced dipl ...19826763939
clustering of spore-specific genes in aspergillus nidulans.we have investigated the chromosomal organization of genes that are expressed specifically in the asexual spores (conidia) of the ascomycete fungus aspergillus nidulans, using two experimental approaches. in the first, 30 different recombinant clones, containing long nuclear dna inserts and at least one spore-specific gene, were selected randomly. the total number of spore-specific genes present in each clone was then determined by rna blot analysis. in the second approach, several chromosomal r ...19826764535
a review of the coordinated research effort on the comparison of test systems for the detection of mutagenic effects, sponsored by the e.e.c.under the environmental research programme of the commission of the european communities a coordinated comparative test programme was started to assess the mutagenic effects of chemicals in as many different assay systems as possible. a preliminary report is given on the results for 5 compounds selected by the contact group "genetic effects of chemicals". 11 laboratories contributed data from tests in their expertise. the compounds were methyl methanesulfonate (mms), n-nitrosodiethylamine (den), ...19806769035
a mutation, adjacent to gene amds, defining the site of action of positive-control gene amdr in aspergillus aspergillus nidulans the acetamidase enzyme is inducible by omega-amino acids, sources of acetyl-coenzyme a, and benzoate. the amdr (or inta) gene is a positive-control gene involved in omega-amino acid induction only. a cis-acting mutation amdi93 located in a complex controlling region adjacent to the acetamidase structural gene was found to abolish induction by omega-amino acids but not induction by other sources of induction. as predicted, this mutation was epistatic to constitutive amdr a ...19806769897
air-borne fungi in the air of barcelona (spain). iii. the genus aspergillus link.during a survey on the presence of species of the genus aspergillus in the air of the city of barcelona (spain), the following species were identified: aspergillus flavus link, a. niger van tieghem, a. fumigatus fresenius, a. clavatus desmazières, a. terreus thom, a. chevalieri (mang.) thom et church, a. niveus bloch, emend. thom et church, a. ochraceus wilhelm, a. versicolor (vuillemin) tiraboschi, and a. amstelodami (mang.) church et thom.19806770271
bacteriophage infection interferes with guanosine 3'-diphosphate-5'-diphosphate accumulation induced by energy and nitrogen starvation in the cyanobacterium anacystis nidulans.anacystis nidulans accumulates large amounts of guanosine 3'-diphosphate-5'-diphosphate (ppgpp) upon nutritional or energy starvation induced by light-to-dark shift, treatment with carbonylcyanide-m-chlorophenylhydrazone (an uncoupler), or treatment with l-methionine-dl-sulfoximine (an inducer of nitrogen starvation). in contrast to healthy a. nidulans cells, those infected by as-1 cyanophage do not respond with ppgpp accumulation when starved after about one-third of the complete infection cyc ...19806777368
regulation of nitrate reductase levels in the cyanobacteria anacystis nidulans, anabaena sp. strain 7119, and nostoc sp. strain 6719.the effect of the nitrogen source on the cellular activity of ferredoxin-nitrate reductase in different cyanobacteria was examined. in the unicellular species anacystis nidulans, nitrate reductase was repressed in the presence of ammonium but de novo enzyme synthesis took place in media containing either nitrate or not nitrogen source, indicating that nitrate was not required as an obligate inducer. nitrate reductase in a. nidulans was freed from ammonium repression by l-methionine-d,l-sulfoximi ...19816780511
[comparative study of the oxygen reduction in photosystem ii of the cyanobacteria, anacystis nidulans and anabaena variabilis].oxygen reduction in the photosystem ii (ps ii) of thylakoid membranes from the cyanobacteria anacystis nidulans and anabaena variabilis was studied in the system simo + dcmu in whose presence competitive electron transport to simo and o2 in possible. the reagents of the mehler reaction were used; these reagents activate oxygen uptake by interacting with the reduced forms of oxygen (malonate and oxalate with o2; glyoxylate and catalase + ethanol with h2o2). the use of the reagents as shown that t ...19806782430
international commission for protection against environmental mutagens and carcinogens. icpemc publication no. 5: an evaluation of the genetic toxicity of dichlorvos. 19806782471
anaplerotic metabolism of aspergillus nidulans and its effect on biomass synthesis in carbon limited chemostats.anaplerotic fixation of carbon dioxide by the fungus aspergillus nidulans when grown under carbon-limited conditions was mediated by pyruvate carboxylase and a phosphoenol pyruvate (pep)-metabolising enzyme which has been tentatively designated as pep carboxylase. the activities of both enzymes were growth rate dependent and measurements of h14co3 incorporation by growing mycelium indicated that they were responsible for almost all the assimilated carbon dioxide. in carbon-limited chemostats, th ...19816783000
co-synthesis of penicillin following treatment of mutants of aspergillus nidulans impaired in antibiotic production with lytic enzymes.mycelia from four mutants of aspergillus nidulans impaired in penicillin production at separate genetic loci were treated with an enzyme complex capable of lysine cell walls, then mixed in all possible paired combinations and grown in osmotically buffered penicillin production media, containing 2-deoxyglucose and an unrefined mixture of polyoxins to prevent cell wall regeneration. the culture filtrates were assayed after 6 d and significant penicillin yields were observed in four of the six poss ...19806785377
picosecond energy transfer in porphyridium cruentum and anacystis nidulans.picosecond energy transfer is measured in anacystis nidulans and porphyridium cruentum. fluorescence is sensitized by a 6-ps laser flash, at 530 nm. the time dependence of fluorescence is measured with reference to the laser pulse. fluorescence is recorded from phycoerythrin (576 nm), r-phycocyanin (640 nm), allophycocyanin (666 nm), photosystem ii chlorophyll (690 nm) and long wave length chlorophyll (715 nm). energy transfer measurements are made at 37 degrees c, 23 degrees c, and 0 degrees c, ...19816788106
intergeneric cosynthesis of penicillin by strains of penicillium chrysogenum, p. chrysogenum/notatum and aspergillus nidulans.a number of mutants impaired in penicillin production have previously been isolated from penicillium chrysogenum and aspergillus nidulans. during cofermentation of osmotically fragile mycelia derived from these strains, in the presence of inhibitors of cell wall regeneration, intergeneric cosynthesis has been demonstrated between mutants which are probably impaired in different parts of th penicillin biosynthetic pathway.19816798163
the isolation of a fungal metabolite which exhibits antimicrobial synergy with sterigmatocystin. 19826802793
temperature-shift analysis of conidial development in aspergillus nidulans. 19826813166
urea and thiourea transport in aspergillus nidulans.wild-type aspergillus nidulans has an active transport system specific for urea which concentrates urea at least 50-fold relative to the extracellular concentration. it is substrate concentration dependent, with an apparent km of 3 x 10-(5) m for urea. competition studies and the properties of mutants indicate that thiourea is taken up by the same system as urea. thiourea is toxic at 5mm to wild-type cells of aspergillus nidulans. mutants, designated urea1 to urea16, resistant to thiourea have b ...19826814421
de novo formation of the niad gene directed protomer in the nadph-nitrate reductase of aspergillus nidulans. 19826817753
isolation of beta-amyrin from the fungus aspergillus nidulans.the pentacyclic triterpene alcohol beta-amyrin, which is commonly found in plants, was isolated from wild-type cultures of the ascomycete fungus aspergillus nidulans. the isolated beta-amyrin was characterized by tlc, glc, and hplc and produced identical mass and 1h nmr spectra to those of authentic beta-amyrin. this material was isolated from static (non-shaking) cultures.19836875511
nuclear movement is beta--tubulin-dependent in aspergillus nidulans. 19806986988
nickel requirement of a urease-deficient mutant in aspergillus nidulans.the addition of nickel ions restored urease activity in vivo and ability to grow on urea in a mutant strain of aspergillus nidulans otherwise unable to utilize urea. this train carries a mutation in the ured locus, one of four loci involved in urea utilization. no other urease-deficient strains tested responded to the presence of nickel ions. the analogous characteristics of the ured mutant and the nitrate reductase and xanthine dehydrogenase associated cnxe mutants in aspergillus nidulans are d ...19806988544
aspergillus nidulans and aspergillus fumigatus as causal agents of bovine mastitis.five cases of bovine udder aspergillosis diagnosed clinically and confirmed by repeated demonstration of fungal hyphae in koh preparations and isolation of the organism from milk sediments are described. in one case the fungus was identified as aspergillus nidulans, in the other 4 cases as a. fumigatus. the most pronounced features in altered udders were multiple abscesses with distinctive colonies of fungal hyphae in the centres, embedded in cell detritus, neutrophils and macrophages. these pur ...19806988991
[antimitotic activity of methylbenzimidazol-2-yl-carbamate (mbc). i. light, electron microscopic and physiological studies of germinating conidia of aspergillus nidulans].in the presence of methylbenzimidazol-2-yl carbamate (mbc) swelling of conidia of aspergillus nidulans was not influenced. the total dna content per nucleus doubled only once, indicating that the first cell cycle was arrested in the g2-period. later rna as well as protein synthesis were inhibited. nuclear migration into the germ tube and tip growth were delayed. mbc-treatment induced nuclear enlargement and inhibited the first nuclear division in the germinating conidia. a characteristic nuclear ...19806990640
mutagenicity of halogenated aliphatic hydrocarbons in salmonella typhimurium, streptomyces coelicolor and aspergillus nidulans.eight structurally related halogenated aliphatic hydrocarbons mono-, di- and trichloroacetaldehyde (the last in the anhydrous and hydrate form), moni-, di- and trichloroethanol and allyl chloride, were tested for their ability to induce gene mutations in prokaryotic and eukaryotic microorganisms. the genetic systems employed were the salmonella reversion test with strain ta1535 and ta100, with and without metabolic activation, a forward and a back-mutation system in s. coelicolor and two forward ...19806991142
a possible rôle for acid phosphatase in gamma-amino-n-butyrate uptake in aspergillus nidulans.previously published work from another laboratory has shown that the mutation pacc-5 in the ascomycete aspergillus nidulans leads to loss of an acid phosphatase (ec activity and is probably located in the structural gene for this enzyme. here, we show that, pleiotropically, pacc-5 considerably reduces gamma-amino-n-butyrate transport levels as shown both by direct uptake measurements and two kinds of growth tests. a reduction in expression of the permease specified by the gaba gene is a ...19806992731
[structure of nucleosome (author's transl)]. 19806994083
developmental gene regulation in aspergillus nidulans. 19806997115
developmental regulation of laccase levels in aspergillus nidulans.asexual spores (conidia) of aspergillus nidulans contain a dark green pigment which is not present in other cell types. synthesis of this pigment is catalyzed, in part, by a developmentally controlled p-diphenol oxidase, or laccase, encoded at the gamma a genetic locus (a. j. clutterbuck, j. gen. microbiol. 70:423-435, 1972). we have investigated the mechanisms regulating expression of the gamma a gene of a. nidulans. vegetative hyphae grown in submerged culture lacked detectable laccase enzyme ...19807000747
membrane-damaging agents cause mitotic non-disjunction in aspergillus nidulans. 19807001225
response of aspergillus nidulans and physarum polycephalum to microwave irradiation.the influence of microwaves on genetic processes in aspergillus nidulans and physarum polycephalum was investigated. suspensions of organisms were exposed in the far zone to 2450-mhz waves at 10 mw/cm2 for one hour in both cw and pulsed (1 microsecond, 600 pps) fields. spores of a. nidulans were irradiated before and during germination. no changes in survival rate or in frequency of morphological mutation were found. polycephalum under the influence of cw microwaves incorporated 3h-thymine into ...19807003154
genetic analysis of resistant mutants to antimitotic benzimidazole compounds in schizosaccharomyces pombe.mutants resistant to the antimitotic compounds thiabendazole and methyl-2-benzimidazole-carbamate were isolated and analyzed genetically in the fission yeast. schizosaccharomyces pombe. they comprised three groups in terms of genetic linkage. mutants in one linkage group (ben1) differed phenotypically from those in the other two (ben2 and ben3). the former were resistant to the compounds at any physiological temperature tested, whereas the latter exhibited temperature dependent resistance. throu ...19807003311
high sensitivity of deoxyribonuclease 4 of aspergillus nidulans to inhibition by orthophosphate. 19807004941
neutral proteinases in germinating conidia and hyphae of aspergillus nidulans. 19807004944
[mutagenic effect of combined exposure to 8-methoxypsoralen or angelicin and long-wave ultraviolet light in uvs-strains of aspergillus nidulans].combined mutagenic effect of near ultraviolet irradiation (nuv, lambda > 320 nm) and angelicin, which forms monoadducts, or 8-methoxypsoralen (8-mop), which forms monoadducts and cross-links in dna, were studied in uvs and uvs+ strains of aspergillus nidulans. mutations were induced intensively by both kinds of furocumarins. the induction of mutations by angelicin testifies the significance of psoralen-pyrimidine monoadducts in mutagenesis. using the method of fractionating nuv-irradiation and s ...19807005024
[x-ray-induced dna degradation in aspergillus nidulans cells. comparative analysis of uv- and xray-induced dna degradation].x-ray irradiation of aspergillus nidulans wild strain cells from logarithmic phase of growth lead to delay of dna synthesis. insignificant enzymatic dna degradation accomplished with its repair takes place. there is no direct dependence between doses of irradiation and levels of dna degradation. investigation of x-ray induced dna degradation in the number of uvs-mutants has demonstrated the existence of two branches of dna degradation: dependent and independent on external source of energy. depe ...19807005025
a third gene affecting gaba transaminase levels in aspergillus nidulans. 19807007164
sorbitol dehydrogenase activity in some galactose non-utilizing mutants of aspergillus nidulans. 19807007224
mitochondrial trna gene clusters in aspergillus nidulans: organization and nucleotide sequence. 19817008953
growth-mediated metabolic activation of promutagens in aspergillus nidulans.7 procarcinogens belonging to different chemical classes (nitrosamines, hydrazoalkanes, oxazaphosphorines and aromatic amines) were tested in a. nidulans for the induction of point mutations with two genetic systems (8-ag resistance and induction of methionine suppressors). dimethylnitrosamine, diethylnitrosamine, nitrosomorpholine, dimethylhydrazine, procarbazine and cyclophosphamide gave positive results with a good dose--effect relationship in the growth-mediated assay, whereas they gave nega ...19817010140
mutagenicity of methyl benzimidazole-2-yl carbamate (mbc) towards aspergillus nidulans (eidam) winter and cladosporium cucumerinum ellis & arth.the ability of methyl benzimidazol-2-yl carbamate (mbc) to induce point mutations to carboxin and mbc resistance was tested in aspergillus nidulans (eidam) winter and cladosporium cucumerinum ellis & arth. a sub-lethal concentration (e.d.50) of mbc, when incorporated into a complete agar medium, induced mbc resistance in germinating conidia of a. nidulans and carboxin resistance in germinating conidia of c. cucumerinum. the significance of these findings in relation to fungicide resistance in th ...19817010147
the ph dependence of the mutagenicity of methyl benzimidazol-2-yl carbamate (mbc) towards aspergillus nidulans (eidam) winter and cladosporium cucumerinum ellis & arth.the ability of methyl benzimidazol-2-yl carbamate (mbc) to induce point mutations to carboxin and mbc resistance in aspergillus nidulans (eidam) winter and cladosporium cucumerinum ellis & arth. was dependent upon the ph value of the agar medium into which it had been incorporated. the relevance of this in relation to testing chemicals for a possible mutagenic activity with microorganisms is discussed.19817010148
genetic regulation of isocitrate lyase activity in aspergillus nidulans. 19807012277
positive regulation in a eukaryote, a study of the uay gene of aspergillus nidulans. ii. identification of the effector binding this publication we report the identification of a protein likely to be coded by uay, a regulatory gene in the ascomycete aspergillus nidulans. uay is a positive control gene necessary for the expression of at least eight unlinked structural genes involved in purine uptake and degradation (scazzocchio and gorton 1977). the physiological effector of the uay system is uric acid, while some of its thioanalogs serve as gratuitous inducers. effector binding proteins were detected by binding to 2-t ...19817012545
isolation of protoplasts from aspergillus nidulans conidiospores.protoplasts were prepared from conidiospores of aspergillus nidulans. the mononucleated conidia gave protoplasts of a uniform size, approximately 5-micron diameter, depending on the strain and the stabilizing medium used. conidia were preincubated with 2-deoxy-d-glucose in a minimal medium at 37 degrees c for 3 h. the swollen conidia were collected, resuspended in a buffer containing 0.4 m (nh4)2so4 as stabilizer, and incubated with oerskovia lytic enzymes at 30 degrees c for 3 or 4 h. approxima ...19817016284
a beta-tubulin mutation in aspergillus nidulans that blocks microtubule function without blocking assembly.we have isolated a heat-sensitive beta-tubulin mutation, bena33, that blocks nuclear division and nuclear movement at restrictive temperature. this blockage demonstrates that the beta tubulin encoded by the bena gene is essential to both processes. the blockage of both processes is suppressed by the alpha-tubulin mutation, tuba1; thus the alpha tubulin encoded by the tuba gene must also be involved in both processes. when bena33 is shifted from a permissive to restrictive temperature, nuclei are ...19817018696
genetic evidence for a second asparaginase in aspergillus nidulans.the apna1 mutation strongly reduces l-asparagine utilization in aspergillus nidulans. the ahra1 mutation, leading to loss of an l-asparaginase (drainas et al., 1977), eliminates residual l-asparagine utilization in double mutant strains also carrying apna1. this additivity suggests that a. nidulans, like saccharomyces cerevisiae (jones, 1977; dunlop et al., 1978), has two l-asparaginases specified by apna and ahr a, respectively, apna has been mapped to a position on the left arm of linkage grou ...19807019388
genetics of penicillin titre in lines of aspergillus nidulans selected through recurrent mutagenesis.genetic analyses of mutations for increased penicillin titre were carried out on two strains of aspergillus nidulans isolated after independent programmes of recurrent mutation and selection, similar to those used industrially for strain improvement. both selected strains were stable in terms of colony morphology and penicillins titre. backcrosses to the unselected ancestor indicated that the increased yield of each strain was due to an induced polygenic system with both additive and non-additiv ...19807019390
induction of point mutations by benomyl in dna-repair-deficient aspergillus nidulans. 19817019695
an alpha-amanitin-resistant dna-dependent rna polymerase ii from the fungus aspergillus alpha-amanitin-resistant dna-dependent rna polymerase ii has been purified from the lower eukaryote aspergillus nidulans to apparent homogeneity by extraction of the enzyme at low salt concentration, polymin p (polyethylene imine) fractionation, binding to ion-exchangers and density gradient centrifugation. by this procedure 0.4 mg of rna polymerase ii can be purified over 6,000-fold from 500 g (wet weight) of starting material with a yield of 25% and a specific activity of 550 units/mg. the ...19817021153
induction of extracellular proteases by egg-white in aspergillus nidulans.aspergillus nidulans when supplemented with egg-white protein (1 %) produced considerable amounts of proteases extracellularly. the order of the appearance of the proteolytic enzymes growth on untreated and heat-inactivated egg-white were studied. they showed ph optima of 5, 7.2 and 9 when assayed at 37 degrees c. it is proposed that one of the factors leading to higher cell mass of a. nidulans in the presence of egg-white is the availability of protease-catalyzed hydrolyzed products of egg-whit ...19817021371
lipid components variation among the temperature-sensitive mutants and wild strain of aspergillus nidulans.the fungus aspergillus nidulans and its two temperature-sensitive mutants were grown in synthetic media at permissive and restrictive temperatures. after seven days of growth, total lipids were extracted and characterised from the mycelia. in the case of the wild strain, an increase in the incubation temperature resulted in an increase in the ratio of unsaturated to saturated fatty acids and was inversely proportional to the ratio of short chain to long chain fatty acids. it was interesting to n ...19817021468
pyruvate carboxylase from aspergillus nidulans. regulatory properties. 19817026241
fatty acid composition of oil synthesized by aspergillus nidulans.the filamentous fungus aspergillus nidulans eidam strain 300 was found to be capable of synthesizing 24.9% oil or remarkably low free fatty acidity, in a chemically defined medium with 34% glucose as sole carbon source. although the total content of oil synthesized was less, utilization of the carbon source is better as shown by the high (8.4) fat coefficient. the major component fatty acids of the oil were palmitic, stearic, oleic and linoleic and are influenced by the source of carbon. palmito ...19817026394
mutagenicity of chemicals of industry and agricultural relevance in salmonella, streptomyces and aspergillus. 19817026896
thiram-induced abnormal chromosome segregation in aspergillus nidulans. 19817027033
evolution of rrna and origin of mitochondria. 19817027053
mutagenicity of monoadducts and cross-links induced in aspergillus nidulans by 8-methoxypsoralen plus 365 nm radiation. 19817027284
a third unlinked gene controlling the pyruvate dehydrogenase complex in aspergillus nidulans.pyruvate dehydrogenase complex mutants of aspergillus nidulans were obtained by ultraviolet treatment and enrichment procedures. among 160 glycolytic mutants, 86 pyruvate dehydrogenase complex mutants (including some temperature-sensitive mutants) were found. in addition to genes pdha and pdhb, which are described in previous studies, a third gene, pdhc, controlling the function of the enzyme complex, was identified. the three genes were not linked and were mapped in the following linkage groups ...19817028719
dominant spore color mutants of aspergillus nidulans defective in germination and sexual development.the ascomycete aspergillus nidulans produces green conidia (asexual spores). recessive mutants which produce yellow conidia have been previously isolated from haploid strains and have been shown to be deficient in laccase (diphenol oxidase), an enzyme that requires copper for activity. using a diploid parent strain, we isolated dominant yellow conidial mutants which, in the haploid state, produced even less laccase activity than a recessive mutant. three isolates of such mutants behaved similarl ...19817028722
rna synthesis during the germination of conidia of aspergillus nidulans.rna accumulates most rapidly in germinating conidia of aspergillus nidulans between 6 h and 14 h after the initiation of germination. 3h-adenine is incorporated into all classes of rna before the emergence of the germ tube, but most of the label appears in rrna. there is an increase in total rna polymerase activity, which occurs in parallel with the increase in rna synthesis. three peaks of rna polymerase activity were separated on phosphocellulose columns and their properties investigated.19817031437
sensitive detection of tritium in southern blot and plaque hybridizations. 19817032353
mutagenicity of pesticides evaluated by means of gene-conversion in saccharomyces cerevisiae and in aspergillus nidulans.nine pesticides, afugan, atrazine, benomyl, captan, daconil, melthaumittel, plantvax, saprol, and wepsin were tested for the induction of mitotic gene-conversion in two different eucaryotic microorganisms, saccharomyces cerevisae and aspergillus nidulans. in s cerevisiae the pesticides were also tested after mouse liver microsomal activation; in a nidulans all tests were performed using both resting and germinating conidia. among the tested pesticides, only captan revealed a consistent genetic a ...19807032901
growth characteristics of saccharomyces cerevisiae and aspergillus nidulans when biotin is replaced by aspartic and fatty acids.when either aerobic or anaerobic cultures of saccharomyces cerevisiae were supplemented with aspartic and fatty acids in place of biotin, stationary phase populations were very small compared with those obtained in the presence of biotin. similarly, these acids failed to fulfil the role of biotin-requiring strain of aspergillus nidulans. furthermore, a requirement for saturated fatty acid was found with anaerobically cultured s. cerevisiae. cells were fragmented when biotin was replaced by aspar ...19817033444
naturally occurring diploid isolates of aspergillus nidulans.six wild isolates belonging to heterokaryon compatibility group a of the birmingham aspergillus nidulans collection were shown to be diploid. five were proven heterozygous for a naturally occurring conditional lethal haploid genotype. it is considered unlikely that these diploids arose by mutation in storage. consequently, somatic diploidy is a regular occurrence in the natural population of this saprophytic species.19817033446
the regulation of phosphoenolpyruvate carboxykinase and the nadp-linked malic enzyme in aspergillus has previously been suggested that the synthesis of phosphoenolpyruvate carboxykinase (ec in aspergillus nidulans is regulated by a repression-derepression mechanism involving a glycolytic intermediate, and not by induction. results obtained using compounds that enter the tricarboxylic acid cycle via 2-oxoglutarate, and that can supply both a carbon and a nitrogen source for a. nidulans, suggest it is more likely that the synthesis of phosphoenolpyruvate carboxykinase is inducible, ...19817033461
mitotic processes which restore genome balance in aspergillus nidulans.previous work had shown that haploid strains of aspergillus nidulans with a duplicate chromosome segment (one in normal position, one translocated to another chromosome) were unstable at mitosis; genome balance was restored by spontaneous deletion of either duplicate segment. diploids with an extra, translocated segment showed high instability which was confined to the excess segments; loss of one of these, usually that in translocated position, gave balanced diploid nuclei and the loss was assu ...19817033469
[otomycosis in the south of chile]. 19817034110
organization of a gene cluster expressed specifically in the asexual spores of a. nidulans.we have investigated the organization and regulation of a 13.3 kb region of the aspergillus nidulans genome that is preferentially expressed during conidiophore development. this cloned dna segment codes for six polysomal poly(a)rnas present in dormant asexual spores (conidia) at from 8 to 50 copies per cell. the genes encoding these rnas occur once per haploid genome, are separate and distinct, appear to be colinear with their mature rna products and are present in both polarities. two of the g ...19817034956
splice points of the third intron in the yeast mitochondrial cytochrome b gene.we report the nucleotide sequences at the splicing junctions of intron 13 of the cytochrome b (box) "long" gene of the mitochondrion of saccharomyces cerevisiae and compare them with the homologous sequences in aspergillus nidulans. the two introns occupy exactly the same position and display an open reading frame in phase with the preceding exon at the 5' end and a blocked region at the 3' end.19817034963
the mosaic organization of the apocytochrome b gene of aspergillus nidulans revealed by dna sequencing.the coding section of the apocytochrome b gene (coba) of the mitochondrial dna of aspergillus nidulans has been completely sequenced. the gene comprises two exons of 507 and 654 bp separated by one intron of approximately 1.1 kb. the derived amino acid sequence shows 61% homology with that of saccharomyces cerevisiae and 51% homology with the cognate human sequence. comparison of these sequences indicates that uga codes for tryptophan in the a. nidulans mitochondrial system. the intron is in exa ...19817034966
a method for the selection of deletion mutations in the l-proline catabolism gene cluster of aspergillus nidulans. 19817035292
aspergillus nidulans as a test organism for chemical the 3 strains of aspergillus nidulans used, bc reduced survival most and 4hmb least. similar trends were found when the effect on gene conversion was studied in a diploid strain and point mutation was scored in a haploid strain. none of the compounds had any effect on mitotic segregation.19827035880
testing for mitotic crossing over and induced aneuploidy using aspergillus nidulans as part of the ukems test programme. 19827035881
induced gene mutation and mitotic non-disjunction in a. nidulans.toxicants of different classes were analysed for capacity to induce gene mutation and mitotic non-disjunction in aspergillus nidulans, using selective and permissive tests, respectively. ethanol, amphotericin b and micanozole, all affecting membrane integrity, induced only non-disjunction, emphasizing the röle of the membrane in mitosis. benomyl and isopropyl-3-chlorophenyl carbamate (cipc), two pesticides which interfere with spindle system, induced only non-disjunction. conversely, mitomycin c ...19817036415
mitotic aneuploidy induced by sodium deoxycholate in aspergillus nidulans.sodium deoxycholate is shown to induce aneuploidy in a heterozygous diploid strain of aspergillus nidulans. it is suggested that this is the result of interference with the normal functioning of the mitotic apparatus through disruption of the nuclear membrane. this effect limits the value of sodium deoxycholate as a paramorphogenic agent in the estimation of the genotoxic effects of environmental and genetic factors.19827038466
aspergillus nidulans: systems and results of tests for chemical induction of mitotic segregation and mutation. i. diploid and duplication assay systems. a report of the u.s. epa gene-tox program. 19827038472
aspergillus nidulans: systems and results of tests for induction of mitotic segregation and mutation. ii. haploid assay systems and overall response of all systems. a report of the u.s. epa gene-tox program. 19827038473
selection for increased penicillin titre following hybridization of divergent lines of aspergillus nidulans.sexual hybridization of two divergent lines of aspergillus nidulans, which had been selected for increased penicillin titre through successive cycles of mutagenesis, released considerable variation for this character. the recovery of segregants with titres equivalent to that of the unselected ancestor suggested that mutations in different genes had been selected in the two lines. however, complementary segregants with substantially improved titres were not found, indicating interactions, probabl ...19817040598
induction of fenarimol-efflux activity in aspergillus nidulans by fungicides inhibiting sterol biosynthesis.fungicides inhibiting sterol biosynthesis belong to chemically distinct classes such as imidazole, morpholine, pyridine, pyrimidine and triazole derivatives. incubation of mycelium of aspergillus nidulans for 90 min with representatives of these fungicides induced an efflux activity which prevented accumulation of fenarimol, a pyrimidine derivative, into the mycelium. induction of this efflux activity reduced the fungitoxicity of fenarimol. addition of oligomycin to mycelium in which fenarimol-e ...19817040601
hydrolysis of vegetable oils and triglycerides by thermotolerant and zoopathogenic species of aspergillus from nigerian palm produce.the ability of aspergillus fumigatus fres. and aspergillus nidulans (eidam) wint obtained from nigerian palm produce to degrade vegetable oils and triglycerides and the production and activity of their extracellular lipases were studied. both species readily hydrolysed palm oil and palm kernel oil among others liberating free fatty acids in the process. good growth with mycelia production of both fungi were also recorded on the triglycerides used as sources of carbon at 37 degrees c with the bes ...19827040975
purification and characterization of the assimilatory nadph-nitrate reductase of aspergillus nidulans.nadph-nitrate reductase [nadph : nitrate oxidoreductase, ec] was purified 500-fold from aspergillus nidulans with an overall yield of about 20%. the purified enzyme catalyzed nadph-nitrate, nadph-cytochrome c, fadh2-nitrate and reduced methyl viologen-nitrate reductase activities. its molecular weight was estimated to be 180,000 from the stokes radius and sedimentation coefficient. the oxidized enzyme exhibited an absorption spectrum having a peak at 412 nm and a broad shoulder at about ...19827042701
polyamine transport in aspergillus nidulans.the uptake of putrescine, spermidine and spermine was studied in aspergillus nidulans using 14c-labelled polyamines. active transport systems, inhibited by azide and regulated by nitrogen availability, exist at least for putrescine and spermidine. putrescine is taken up two to three times more rapidly than spermidine, reflecting a lower km for the former substrate. the two uptake systems appear to be independent, spermidine uptake being inhibited by both putrescine and spermine, while putrescine ...19827042908
[genetic control of recombination processes in aspergillus nidulans. iv. the effect of uvs mutations on the frequency of spontaneous and nitrosomethylurea-induced intragenic mitotic recombination].effects of three uvs mutations were studied on spontaneous and nitrosomethyl-induced intragenic mitotic segregation in the metha region of the chromosome ii in aspergillus diploids homozygous for uvs and heteroallelic for metha mutation. the reversion frequencies of metha alleles in parent haploid strains were also determined. all the mutations increased the frequency of spontaneous and decreased that of induced intragenic mitotic recombination. the frequency of spontaneous reversions was decrea ...19827047300
genetical and biochemical aspects of quinate breakdown in the filamentous fungus aspergillus the ascomycetous fungus aspergillus nidulans, the expression of two inducible, contiguous or closely linked genes (qutb and qutc) which encode enzymes for quinate breakdown to protocatechuate, appears to be controlled by the product of a tightly linked third genet (quta). the qut gene cluster locates on chromosome viii. the catalytic steps required for this conversion are dehydrogenase, dehydroquinase, and dehydratase, and these activities are induced by the presence of quinate in a similar m ...19827049157
positive regulation in a eukaryote, a study of the uay gene of aspergillus nidulans: i. characterization of alleles, dominance and complementation studies, and a fine structure map of the uay--oxpa this paper we characterize genetically a positive eukaryotic regulatory gene: the uay gene of the ascomycete aspergillus nidulans. several steps in the uptake and degradation of purines are under the control of the uay gene (summarized in scazzocchio and gorton 1977). in the present paper 12 uay-mutations are characterized with respect to their inducibility for adenine deaminase, xanthine dehydrogenase (purine hydroxylase i) and urate oxidase and by the absence of the uric acid-xanthine perme ...19827049832
purification and characterization of the conidial laccase of aspergillus nidulans.conidial laccase of aspergillus nidulans was purified by standard protein purification methods. although the purified material showed a cluster of several protein bands on a nondenaturing gel, each of these protein bands had laccase activity. all bands of activity, however, were absent in a strain carrying a mutation in the structural gene for laccase. concentrated solutions (greater than 1 mg/ml) were bright blue, suggesting that, like other laccases, this enzyme contains copper. the enzyme con ...19827050088
ergosterol and lanosterol from aspergillus nidulans.ergosterol was identified as the major free sterol of aspergillus nidulans by thin-layer chromatography, alumina column chromatography, gas-liquid chromatography, high-performance liquid chromatography, uv spectroscopy, proton magnetic resonance spectroscopy and mass spectral analysis. lanosterol, the initial cyclized precursor of ergosterol, was identified as a minor component of the free sterols. in the steryl ester material, however, lanosterol was usually more abundant than ergosterol, sugge ...19827050295
a possible regulatory gene for the molybdenum-containing cofactor in aspergillus nidulans.aspergillus nidulans has three molybdoenzymes, nitrate reductase, purine hydroxylase i and purine hydroxylase ii. these three enzymes share a molybdenum-containing cofactor whose synthesis requires the integrity of five loci, designated cnxabc, cnxe, cnxf, cnxg and cnxh. here we report the existence of a sixth locus, designated cnxj, which might be involved inthe regulation of cofactor levels. when grown in the presence, but not in the absence, of tungstate or methylammonium, strains carrying cn ...19827050297
molecular and genetic methods for studying mitosis and spindle proteins in aspergillus nidulans. 19827050618
metabolism of 5'-methylthioadenosine in aspergillus nidulans. an alternative pathway for methionine synthesis via utilization of the nucleoside methylthio group.experiments in which 5'-methylthioadenosine was used as a culture supplement for methionine-requiring mutants of aspergillus nidulans with various enzymatic lesions indicated that the methylthio group derived from the nucleoside can be recycled to methionine. the results strongly suggest that methionine may be synthesized in the reaction catalyzed by homocysteine synthase (ec in which o-acetylhomoserine is an acceptor of the methylthio group. the first step on the salvage pathway of t ...19827052140
the microbiology of spent mushroom compost and its dust.microorganisms in spent steamed mushroom compost and its dust were enumerated, and identified. some phase ii (indoor composting) compost samples were also examined. steaming of spent compost resulted in a 70-76% reduction in microbial numbers. total counts made with compost fusion agar were approximately two logs greater than those for nutrient agar. the most common bacterial isolate was bacillus licheniformis. the most common actinomycete isolates were streptomyces diastaticus and thermoactinom ...19817197578
the bgl1 gene of trichoderma reesei qm 9414 encodes an extracellular, cellulose-inducible beta-glucosidase involved in cellulase induction by sophorose.we have investigated the effect of disruption of the bgl1-(beta-glucosidase l-encoding) gene of trichoderma reesei on the formation of other beta-glucosidase activities and on the induction of cellulases. to this end the bgl1 locus was disrupted by insertion of the aspergillus nidulans amds (acetamidase-encoding) gene. the bgl1-disrupted strain did not produce the 75 kda extracellular beta-glucosidase on cellulose or lactose, but still formed beta-glucosidase activity on glucose, cellobiose, xyl ...19957476163
stcs, a putative p-450 monooxygenase, is required for the conversion of versicolorin a to sterigmatocystin in aspergillus nidulans.sterigmatocystin (st) and aflatoxin are carcinogenic end point metabolites derived from the same biochemical pathway, which is found in several aspergillus spp. recently, an st gene cluster, containing approximately 25 distinct genes that are each proposed to function specifically in st biosynthesis, has been identified in aspergillus nidulans. each of these structural genes is named stc (sterigmatocystin) followed by a consecutive letter of the alphabet. we have previously described stcu (forme ...19957486998
sepb: an aspergillus nidulans gene involved in chromosome segregation and the initiation of aspergillus nidulans conidia, cytokinesis (septation) is delayed until three rounds of nuclear division have been completed. this has permitted the identification of essential genes that are involved in the coordination of cytokinesis with nuclear division. conditional mutations in the sepb gene block septation but allow germinating spores to complete the first three rounds of nuclear division at restrictive temperature. sepb3 mutants demonstrate transient delays in m-phase, accumulate aneupl ...19957489714
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