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chromatography and generation of specific antisera to synthetic peptides from a protective boophilus microplus antigen.four oligopeptides corresponding to predicted antigenic regions of the protective bm86 glycoprotein of the cattle tick boophilus microplus were synthesized and purified. three were conjugated to carrier proteins and antisera raised in rabbits and cows. all elicited antipeptide antibodies that recognized bm86 and recombinant derived products in western blots; however, only one produced antiserum capable of recognizing native bm86 in an indirect immunofluorescence assay. ticks fed in vitro on this ...19902229227
characterization of a glycerol kinase mutant of aspergillus niger.a glycerol-kinase-deficient mutant of aspergillus niger was isolated. genetic analysis revealed that the mutation is located on linkage group vi. the phenotype of this mutant differed from that of a glycerol kinase mutant of aspergillus nidulans in its ability to utilize dihydroxyacetone (dha). the weak growth on glycerol of the a. niger glycerol kinase mutant showed that glycerol phosphorylation is an important step in glycerol catabolism. the mutant could still grow normally on dha because of ...19902230717
nucleotide and amino acid sequences of the conidium-specific spoc1-c1d gene from aspergillus nidulans. 19902243803
the identification of mutations in aspergillus nidulans that lead to increased levels of adhii.there are at least three alcohol dehydrogenases in aspergillus nidulans. adhii has been observed in polyacrylamide gels stained for adh activity but, unlike adhi and adhiii, no physiological function has been attributed to it. this paper describes mutations that have been isolated from strains carrying a deletion in the structural gene for adhi (alca) and its adjacent positively-acting regulatory gene (alcr) that restore some ability to utilise ethanol as a carbon source. the mutations map at th ...19902245474
light is required for conidiation in aspergillus nidulans.light is necessary for asexual sporulation in aspergillus nidulans but will elicit conidiation only if irradiation occurs during a critical period of development. we show that conidiation is induced by red light and suppressed by an immediate shift to far red light. conidiation-specific gene functions switch from light-independent to light-dependent activities coincident with the expression of brla, a regulator of conidiophore development. we also show that light dependence is abolished by a mut ...19902253875
nitrogen regulation in aspergillus: are two fingers better than one?the area gene, mediating nitrogen metabolite repression in aspergillus nidulans, encodes a positive-acting regulatory protein with a single putative dna-binding 'zinc finger' which is remarkably similar to the two 'zinc fingers' of the major regulatory protein of vertebrate erythroid cells (gf-1/eryf1/nf-e1). the area-300 mutation alters the specificity of gene activation in that it elevates expression of certain structural genes whilst reducing expression of certain others. it is an 'in-frame' ...19902253884
purification, cloning, and primary structure of an enantiomer-selective amidase from brevibacterium sp. strain r312: structural evidence for genetic coupling with nitrile hydratase.an enantiomer-selective amidase active on several 2-aryl and 2-aryloxy propionamides was identified and purified from brevibacterium sp. strain r312. oligonucleotide probes were designed from limited peptide sequence information and were used to clone the corresponding gene, named amda. highly significant homologies were found at the amino acid level between the deduced sequence of the enantiomer-selective amidase and the sequences of known amidases such as indoleacetamide hydrolases from pseudo ...19902254253
identification of an amino acid substitution in the bena, beta-tubulin gene of aspergillus nidulans that confers thiabendazole resistance and benomyl supersensitivity.we are using molecular genetic techniques to identify sites of interaction of beta-tubulin with benzimidizole anti-microtubule agents. we have developed a marker-rescue technique for cloning mutant alleles of the bena, beta-tubulin gene of aspergillus nidulans and have used the technique to clone two mutant bena alleles, bena16 and bena19. these are the only a. nidulans alleles known to confer resistance to the benzimidazole antimicrotubule agent thiabendazole and supersensitivity to other benzi ...19902257633
heterologous gene expression by filamentous fungi: secretion of human interleukin-6 by aspergillus nidulans.expression vectors for human interleukin-6 (hil6) contain an expression cassette consisting of the aspergillus niger glaa promoter and the aspergillus nidulans argb terminator. the secretion signals were either those of glaa or that of the authentic hil6 peptide. the constructs under study were introduced into a. nidulans and a. niger by means of cotransformation. no il6 activity could be detected in the medium of a cotransformed a. niger strain, although transcripts corresponding with the il6 c ...19902258049
a translocation activating the cryptic nitrogen regulation gene areb inactivates a previously unidentified gene involved in glycerol utilisation in aspergillus nidulans.the chromosome viii translocation breakpoint of the areb-404 translocation, selected for its ability to activate the cryptic nitrogen metabolism regulatory gene areb, and the mutation glcd-100 both lead to loss of mitochondrial fad-dependent sn-glycerol-3-phosphate dehydrogenase in aspergillus nidulans. these two lesions therefore define glcd, a second gene (in addition to glcb) where mutation can result in loss of this enzyme. the glcd gene has been localised to a centromere-proximal region of ...19902259335
fungal flora associated with combine harvester wheat and sorghum dusts from egypt.107 species and 8 species varieties belonging to 44 genera were collected from combine harvester wheat and sorghum dusts (35 genera and 91 species + 4 varieties) and from the atmosphere of their hay sites (26 genera and 69 species + 4 varieties) on glucose- and cellulose-czapek's dox agar at 28 degrees c and 45 degrees c. the mycoflora of wheat and sorghum dusts were basically similar on the two types of media and the most common fungi were: alternaria alternata, aspergillus flavus, a. fumigatus ...19902266490
solubilisation of a cell wall bound invertase in aspergillus nidulans.aspergillus nidulans produces an extracellular invertase when incubated in the presence of sucrose and about half of the activity produced was found to be associated with the mycelium. sixty percent of this mycelial invertase could be solubilised by simple mechanical disruption. among the agents tested for solubilisation of invertase, proteinase k and dithiothreitol were the most effective.19902272493
molecular basis for determining the sensitivity of eucaryotes to the antimitotic drug rhizoxin.rhizoxin, an antibiotic, exhibits potent anti-mitotic activity against most eucaryotic cells including those of higher vertebrates, plants and fungi by binding to beta-tubulin. the bena gene of three independently isolated rhizoxin-resistant (rhir) mutants of aspergillus nidulans was cloned, sequenced and compared with that of the wild-type, rhizoxin-sensitive (rhis) strain. in all three rhir mutants, the aac codon for asn-100 of the bena beta-tubulin gene was altered to atc, coding for ile. seq ...19902274023
genetic analysis of amds transformants of aspergillus niger and their use in chromosome mapping.the aspergillus nidulans gene coding for acetamidase (amds) was introduced into a. niger by transformation. twelve amd+ transformants were analysed genetically. the amds inserts were located in seven different linkage groups. in each transformant the plasmid was integrated in only a single chromosome. our (non-transformed) a. niger strains do not grow on acetamide and are more resistant to fluoroacetamide than the transformants. diploids hemizygous for the amds insert have the amd+ phenotype. we ...19902274031
alcohol dehydrogenase iii in aspergillus nidulans is anaerobically induced and post-transcriptionally regulated.an alcohol dehydrogenase was shown to be induced in aspergillus nidulans by periods of anaerobic stress. this alcohol dehydrogenase was shown to correspond to the previously described cryptic enzyme, alcohol dehydrogenase iii (mcknight et al. 1985), by analysis of a mutation in the structural gene of alcohol dehydrogenase iii, alcc, created by gene disruption. survival tests on agar plates showed that this enzyme is required for long-term survival under anaerobic conditions. northern blot analys ...19902274033
sequence, organization and expression of the core histone genes of aspergillus nidulans.the core histone gene family of aspergillus nidulans was characterized. the h2a, h2b and h3 genes are unique in the a. nidulans genome. in contrast there are two h4 genes, h4.1 and h4.2. as previously reported for the h2a gene (may and morris 1987) introns also interrupt the other core histone genes. the h2b gene, like the h2a gene, is interrupted by three introns, the h3 and h4.1 gene are each interrupted by two introns and the h4.2 gene contains one intron. the position of the single intron in ...19902274040
expression and secretion in aspergillus nidulans and aspergillus niger of a cell surface glycoprotein from the cattle tick, boophilus microplus, by using the fungal amds promoter system.a cell surface glycoprotein (bm86) from cells of the digestive tract of the cattle tick boophilus microplus, which has been shown to elicit a protective immunological response in vaccinated cattle, was expressed and secreted in the filamentous fungi aspergillus nidulans and aspergillus niger by using the fungal amds promoter system. the cloned gene coded for the bm86 secretory signal and all of the bm86 mature polypeptide except for the hydrophobic carboxy-terminal segment. high levels of bm86 m ...19902275533
an electrophoretic karyotype of aspergillus niger.an electrophoretic karyotype of aspergillus niger was obtained using contour-clamped homogeneous electric field (chef) gel electrophoresis. chromosome-sized dna was separated into four bands. seven of the eight linkage groups could be correlated with specific chromosomal bands. for this purpose dna preparations from seven transformant strains of a. niger each carrying the heterologous amds gene of aspergillus nidulans on a different chromosome were analysed. some of the assignments were confirme ...19902277644
development of a homologous transformation system for aspergillus parasiticus with the gene encoding nitrate reductase.the nitrate reductase structural gene (niad) and an niad mutant strain were isolated from aspergillus parasiticus and used to develop a homologous transformation system. a transformation frequency of 110 to 120 transformants per microgram linear dna was obtained with the 10.9 kb plasmid psl82, which contained the niad gene of a. parasiticus. plasmid psl82 was also capable of complementing aspergillus nidulans fgsc a691, a niad mutant, though at lower frequencies. southern hybridization analyses ...19902277647
investigation of the het genes that control heterokaryon incompatibility between members of heterokaryon-compatibility (h-c) groups a and g1 of aspergillus nidulans.a chromosome assay method was used to determine the heterokaryon compatibility relationships between strains belonging to heterokaryon-compatibility (h-c) groups a and g1 of aspergillus nidulans. a hybrid strain (rd15) was isolated following protoplast fusion of strains 65-5 (h-ca) and 7-141 (h-cg1). the morphology of rd15 was severely abnormal compared to diploid strains of a. nidulans produced from heterokaryon-compatible haploid parents. inocula of rd15 were induced to haploidize on medium co ...19902283501
the genetics of conidiophore pigmentation in aspergillus nidulans.the grey-brown pigmentation of aspergillus nidulans conidiophores depends on the functions of two 'ivory' loci. ivob codes for a developmental specific phenol oxidase, and mutants accumulate its substrate n-acetyl-6-hydroxytryptophan. ivoa mutants are unable to make this substrate. yga mutants are also poorly pigmented, and extracts require copper salts to activate both the phenol oxidase and conidial laccase. ivoa and ivob mutants partially suppress the spore colour phenotype of yga mutants. co ...19902283502
an evolutionary comparison of acinetobacter calcoaceticus trpf with trpf genes of several organisms.the deduced amino acid sequence of acinetobacter calcoaceticus n-(5'-phosphoribosyl) anthranilate isomerase (prai), which is coded by trpf, was compared with trpf of caulobacter crescentus, escherichia coli, bacillus subtilis, saccharomyces cerevisiae, neurospora crassa, and aspergillus nidulans. sixty percent of identical or similar amino acids were located in alpha/beta tim (triose-phosphate isomerase) barrels and in residues important in substrate binding and catalysis. in addition, the analy ...19902299982
the purification and characterization of 3-dehydroquinase from streptomyces coelicolor.the enzyme 3-dehydroquinase was purified over 4000-fold to homogeneity from streptomyces coelicolor. the subunit mr estimated from polyacrylamide-gel electrophoresis in the presence of sds was 16,000. the native mr estimated by gel filtration on a superose 6 column was 209,000, indicating that the enzyme is a large oligomer. the enzyme was found to be extremely thermostable. this stability, along with the structural and kinetic properties of the enzyme, suggest that it is very similar to the qui ...19902306211
how does the cell count the number of ectopic copies of a gene in the premeiotic inactivation process acting in ascobolus immersus?repeated genes, artificially introduced in ascobolus immersus by integrative transformation, are frequently inactivated during the sexual phase. inactivation is observed in about 50% of meioses if duplicated genes are at ectopic chromosomal locations, and in 90% of meioses if genes are tandemly repeated. inactivation is associated with extensive methylation of the cytosine residues of the duplicated sequences and is induced in the still haploid nuclei of the dikaryotic cell which will undergo ka ...19902311917
studies on the mycoflora of aswan high dam lake, egypt: monthly variations.fifty-one species and one variety appertaining to twenty one genera of mesophilic fungi were recovered from the monthly samples of marginal water (44 species, 1 variety and 18 genera) and submerged mud (78 species, 1 variety and 30 genera) of aswan high dam lake during the period from july 1985 to december 1986. the most common species were aspergillus fumigatus, a. flavus, a. terreus, a. niger and penicillium funiculosum. the highest fungal populations were almost detected either in october, in ...19902352135
the complete dna sequence of the mitochondrial genome of podospora anserina.the complete 94,192 bp sequence of the mitochondrial genome from race s of podospora anserina is presented (1 kb = 10(3) base pairs). three regions unique to race a are also presented bringing the size of this genome to 100,314 bp. race s contains 31 group i introns (33 in race a) and 2 group ii introns (3 in race a). analysis shows that the group i introns can be categorized according to families both with regard to secondary structure and their open reading frames. all identified genes are tra ...19902357736
transformation of the rice blast fungus magnaporthe grisea to hygromycin b resistance.low frequency, integrative transformation of three fertile hermaphroditic strains of magnaporthe grisea has been achieved using plasmid pan7-1 and cosmid pan7-2, which contain an escherichia coli hygromycin b phosphotransferase gene linked to aspergillus nidulans regulatory sequences.19902357737
nucleases in the autolysis of filamentous fungi.rnase and dnase activities were studied in seven fungi of the subdivisions ascomycotina, zygomycotina and basidiomycotina during their autolysis, and extracellular and intracellular rnase and dnase were found. rnase specific activity reached higher levels than dnase specific activity in the culture liquid and mycelial extract, except in aspergillus nidulans. generally maximal rnase specific activities were observed at the onset of autolysis in the culture liquid. in the mycelial extract an incre ...19902379813
genetic analysis of aspergillus niger: isolation of chlorate resistance mutants, their use in mitotic mapping and evidence for an eighth linkage group.this paper describes the use of chlorate resistant mutants in genetic analysis of aspergillus niger. the isolated mutants could be divided into three phenotypic classes on the basis of nitrogen utilization. these were designated nia, nir and cnx as for aspergillus nidulans. all mutations were recessive to their wild-type allele in heterokaryons as well as in heterozygous diploids. the mutations belong to nine different complementation groups. in addition a complex overlapping complementation gro ...19902381424
localization of pyruvate carboxylase in organic acid-producing aspergillus strains.the localization of pyruvate carboxylase (cytosolic or mitochondrial) was studied in nine different aspergillus species (14 strains). in some species (a. aculeatus, a. flavus, a. foetidus, a. nidulans, a. ochraceus, and a. sojae), the pyruvate carboxylase activity could be detected only in the cytosolic fraction of the cells. pyruvate carboxylase has been found only in the mitochondrial fraction of two strains of aspergillus wentii. in aspergillus oryzae and in five strains of aspergillus niger, ...19902383004
high-efficiency transformation system for the biocontrol agents, trichoderma spp.we have developed an efficient transformation system based on the use of polyethylene glycol and cacl2 for the biocontrol agents, trichoderma spp. transformation was obtained with the plasmid pan7-1, carrying a bacterial hygromycin-resistance gene as a selectable marker, under the control of aspergillus nidulans heterologous expression signals. the system described here yielded 200-800 transformants per microgram of dna. transformants contained several copies of the plasmid integrated into their ...19902388561
survey of the mycoflora and mycotoxins of cotton seeds and cotton seed products in egypt.thirty-nine species and 16 fungal genera were isolated from egyptian cotton seeds, cotton seed meal and cotton seed cake on 1% glucose-czapek's agar medium incubated at 28 degrees c. aspergillus was the most frequent genus and it emerged in 87-100% of the samples contributing 70-98% of total fungi in the three substrates tested. the most common species were a. niger, a. flavus, a. fumigatus, a. terreus and rhizopus stolonifer; a. niger, a. fumigatus and penicillium corylophilum; and a. niger, a. ...19902388680
cloning and analysis of beta-tubulin gene from a protoctist.we have isolated and characterized by restriction endonuclease mapping, transcription pattern, and dna sequencing a beta-tubulin gene from the coenocytic freshwater protoctist, achlya klebsiana. the gene is intronless and has a single open reading frame that encodes a 444-amino acid residue polypeptide of mr 49,856. the protein shows a high degree of homology to other beta-tubulins, 85% identity to human beta-tubulin and 89% identity to beta-tubulin of the sporozoan (also a protoctist) plasmodiu ...19902394720
homologous transformation of cephalosporium acremonium with the nitrate reductase-encoding gene (niad).we report the development of a homologous transformation system for cephalosporium acremonium using the niad gene of the nitrate assimilation (na) pathway. mutants in the na pathway were selected on the basis of chlorate resistance by conventional means. screening procedures were developed to differentiate between nitrate reductase apoprotein structural gene mutants (niad) and molybdenum cofactor gene mutants (cnx) as wt c. acremonium, unlike most filamentous fungi, fails to grow on minimal medi ...19902401400
the aspergillus nidulans npea locus consists of three contiguous genes required for penicillin biosynthesis.clones of aspergillus nidulans genomic dna spanning 20 kb have been isolated and shown by a combination of classical and molecular genetic means to represent the npea locus, previously found to be one of four loci (npea, npeb, npec and nped) involved in the synthesis of penicillin. as well as containing the gene encoding the second enzyme for penicillin biosynthesis, namely isopenicillin n synthetase (ipns) (designated ipna), our results show that these clones (psta200, psta201 and psta207) cont ...19902403928
selective overexpression of the qute gene encoding catabolic 3-dehydroquinase in multicopy transformants of aspergillus nidulans.the three enzymes necessary to catabolize quinate to protocatechuate are inducible by quinic acid, and transcription of their corresponding genes is controlled by the action of a positively acting activator gene and a negatively acting repressor gene. transformed strains of aspergillus nidulans containing multiple copies of the activator gene (quta) but single copies of the other qut genes retain normal regulation of the gene cluster and do not show any overexpression of the three quinic acid ca ...19902405841
the regulatory gene area mediating nitrogen metabolite repression in aspergillus nidulans. mutations affecting specificity of gene activation alter a loop residue of a putative zinc finger.the regulatory gene area mediating nitrogen metabolite repression in aspergillus nidulans has been sequenced and its transcript mapped and orientated. a single orf can encode a protein of 719 amino acids. a 52 amino acid region including a putative 'zinc finger' strongly resembles putative dna binding regions of the major regulatory protein of erythroid cells. the derived protein sequence also contains a highly acidic region possibly involved in gene activation and 22 copies of the motif s(t)pxx ...19901970293
comparison and cross-species expression of the acetyl-coa synthetase genes of the ascomycete fungi, aspergillus nidulans and neurospora crassa.the genes encoding the acetate-inducible enzyme acetyl-coenzyme a synthetase from neurospora crassa and aspergillus nidulans (acu-5 and faca, respectively) have been cloned and their sequences compared. the predicted amino acid sequence of the aspergillus enzyme has 670 amino acid residues and that of the neurospora enzyme either 626 or 606 residues, depending upon which of the two possible initiation codons is used. the amino acid sequences following the second alternative aug show 86% homology ...19901972535
restriction enzyme analysis of mitochondrial dna of the aspergillus flavus group: a. flavus, a. parasiticus, and a. nomius.mitochondrial dna restriction fragment length polymorphisms were identified that clearly distinguish aspergillus flavus, a. parasiticus, and a. nomius. mitochondrial dnas of a. flavus and a. parasiticus were found to be circular, and their size was estimated size to be 32 kilobases. a restriction map was constructed for the mitochondrial genome of an a. parasiticus isolate by using four restriction endonucleases. four genes tested were found to have the same order as in the mitochondrial genome ...19901976299
use of nuclear dna restriction fragment length polymorphisms to analyze the diversity of the aspergillus flavus group: a. flavus, a. parasiticus, and a. nomius.recombinant dna clones carrying high-copy or low-copy sequences from aspergillus nidulans and neurospora crassa were used to identify restriction fragment length polymorphisms (rflps) diagnostic for members of the a. flavus group: a. flavus, a. parasiticus, and a. nomius. these fungi were resolved into three distinct categories when they were grouped according to rflp patterns. subgroups within these categories were also evident. this limited rflp analysis of nuclear dna of members of the a. fla ...19901976300
premeiotic disruption of the neurospora crassa malate synthase gene by native and divergent dnas.repeat-induced point mutation (rip) has been used to generate new mutations in the previously uncharacterised gene for malate synthase in neurospora crassa. molecular clones carrying the am (nadp-glutamate dehydrogenase) gene and the malate synthase gene from either n. crassa or aspergillus nidulans have been introduced into neurospora as ectopic duplicate copies by transformation, selecting for the am+ function in a deletion host. a number of meiotic progeny derived from these transformants wer ...19901979142
sequences of isopenicillin n synthetase genes suggest horizontal gene transfer from prokaryotes to eukaryotes.evolutionary distances between bacterial and fungal isopenicillin n synthetase (ipns) genes have been compared to distances between the corresponding 5s rrna genes. the presence of sequences homologous to the ipns gene has been examined in dnas from representative prokaryotic organisms and ascomycotina. the results of both analyses strongly support two different events of horizontal transfer of the ipns gene from bacteria to filamentous fungi. this is the first example of such a type of transfer ...19901979440
restriction fragment length polymorphisms in isolates of aspergillus fumigatus probed with part of the intergenic spacer region from the ribosomal rna gene complex of aspergillus nidulans.differences in restriction fragment length polymorphisms (rflps) have been detected in isolates of aspergillus fumigatus. genomic dna from 11 isolates was digested with ecori, separated by electrophoresis, southern blotted and probed with dna from the intergenic spacer or non-transcribed spacer region of the rrna gene complex of aspergillus nidulans. three distinct rflp patterns were detected which differed from the control patterns observed with a. nidulans, aspergillus flavus and aspergillus n ...19901980128
hen egg white lysozyme expressed in, and secreted from, aspergillus niger is correctly processed and folded.we transformed aspergillus niger with the full length cdna gene encoding hen egg-white lysozyme (hewl) and its secretion signal sequence. lysozyme levels up to 12 mg/l were secreted when expression was controlled by the a. awamori glucoamylase (gam) promoter and 1 mg/l when controlled by the a. nidulans glyceraldehyde-3-phosphate dehydrogenase (gpd) promoter. n-terminal sequence analysis of the recombinant protein indicated that the signal peptide was correctly processed by the a. niger secretor ...19901366900
physical characterization of the aldehyde-dehydrogenase-encoding gene of aspergillus niger.to facilitate a better understanding of the regulation of alda, the gene encoding aldehyde dehydrogenase (alddh) in the ascomycete fungus, aspergillus niger, the gene has been physically characterized. the complete nucleotide (nt) sequence of the gene and its flanking regions has been determined. analysis of the gene has revealed the presence of three introns. the homologous gene in the related fungus, aspergillus nidulans, contains only two introns. the coding regions of these genes, excluding ...19892606357
tryptophan auxotrophic mutants in aspergillus niger: inactivation of the trpc gene by cotransformation mutagenesis.aspergillus niger tryptophan auxotrophic mutants have been isolated after uv irradiation of conidiospores. the mutants belong to two different complementation groups, trpa and trpb, which complement each other in heterokaryons. neither of the mutations could be complemented with the cloned a. niger trpc gene. to obtain a. niger trpc mutants in a direct way, gene inactivation by cotransformation was performed. for this purpose an in-frame gene fusion between the a. niger trpc and escherichia coli ...19892615762
amplified expression of ribulose bisphosphate carboxylase/oxygenase in pbr322-transformants of anacystis nidulans.prior research suggested that the genes for large (l) and small (s) subunits of ribulose bisphosphate carboxylase/oxygenase (rubisco) are amplified in ampicillin-resistant pbr322-transformants of anacystis nidulans 6301. we now report that chromosomal dna from either untransformed or transformed a. nidulans cells hybridizes with nick-translated [32p]-pbr322 at moderately high stringency. moreover, nick-translated [32-p]-pcs75, which is a puc9 derivative containing a psti insert with l and s subu ...19892644909
delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine synthetase from aspergillus nidulans. the first enzyme in penicillin biosynthesis is a multifunctional peptide synthetase.a multienzyme catalyzing the formation of delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine, the first free intermediate in penicillin biosynthesis, was detected in an assay measuring the formation of tripeptide from l-[u-14c]valine in the presence of l-alpha-aminoadipic acid, l-cysteine, atp, mg2+ ions, and dithioerythritol. enzyme was extracted from dry mycelium using a buffer with a high glycerol concentration and thiol protective agent to stabilize enzyme activity. in five steps the enzyme wa ...19892645274
genotoxic effects of niclosamide in aspergillus nidulans.a 2-5-month treatment with niclosamide, a widely used drug in developing countries, has been reported to induce lymphosarcomas in toad liver and kidney. the genotoxic effects of this drug have also been evaluated in salmonella typhimurium, in somatic and germinal cells of mice and in human lymphocytes exposed in vitro and in vivo. the present study shows that niclosamide is also capable of inducing mitotic crossing-over and non-disjunction in aspergillus nidulans, which points to the wide potent ...19892649793
identification of gamma-tubulin, a new member of the tubulin superfamily encoded by mipa gene of aspergillus nidulans.microtubules, which are essential for mitosis and many other cytoskeletal functions, are composed primarily of alpha- and beta-tubulin. the properties of microtubules are due, in part, to proteins other than tubulins that are part of, or interact with, microtubules and the identification and characterization of such proteins is important to understanding how microtubules function. analyses of mutations at the mipa (microtubule interacting protein) locus of aspergillus nidulans have suggested tha ...19892649796
transformation in fungi.transformation with exogenous deoxyribonucleic acid (dna) now appears to be possible with all fungal species, or at least all that can be grown in culture. this field of research is at present dominated by saccharomyces cerevisiae and two filamentous members of the class ascomycetes, aspergillus nidulans and neurospora crassa, with substantial contributions also from fission yeast (schizosaccharomyces pombe) and another filamentous member of the class ascomycetes, podospora anserina. however, tr ...19892651864
a translocation associated, loss-of-function mutation in the nitrogen metabolite repression regulatory gene of aspergillus nidulans can revert intracistronically.the arear-18 mutation is a loss-of-function mutation in area, the positive acting regulatory gene mediating nitrogen metabolite repression in aspergillus nidulans. it results from a reciprocal translocation which splits the coding region into 5' and 3' moieties. surprisingly, we have selected rare intracistronic revertants of arear-18. from crosses heterozygous for arear-18 revertant alleles, duplication-deficiency progeny containing two copies of a substantial portion of chromosome iv but lacki ...19892651886
regulatory genes in aspergillus nidulans.a major area for the study of gene regulation in lower eukaryotes has been the coordinated control of catabolic enzyme synthesis. studies of catabolic gene regulation aim to define how interactions between input signals and regulatory proteins are transmitted to the transcription machinery to bring about changes in gene expression. in the past, mutants altered in the utilization of a wide variety of substrates have been characterized in aspergillus nidulans. recently, the development of a transf ...19892652389
interrelated regulation of sulphur-containing amino-acid biosynthetic enzymes and folate-metabolizing enzymes in aspergillus nidulans.in aspergillus nidulans homocysteine can be metabolized both to cysteine and methionine. mutants impaired in the main pathway of cysteine synthesis or in the sulphate assimilation pathway show a low pool of glutathione and elevated levels of homocysteine synthase and of the homocysteine-to-cysteine pathway enzymes. on the other hand, the level of methionine synthase and other enzymes of folate metabolism is depressed in these mutants. this anticoordinated regulation provides a mechanism controll ...19892653822
beta-lactam biosynthetic genes. 19892654524
different action of mms and ems in uv-sensitive strains of aspergillus nidulans.the repair of methyl methanesulfonate (mms) and ethyl methanesulfonate (ems) damages has been investigated in the fungus aspergillus nidulans. 4 uv-sensitive mutants, namely uvsb, uvsd, uvsf and uvsh have been tested for their sensitivity and mutability to the above-mentioned agents. the results obtained show that: (1) uvsb and uvsd mutants are no more sensitive than the wild-type strain to the lethal action of ems. in contrast, they are more sensitive to mms; (2) uvsf and uvsh mutants are more ...19892654626
interactions of three sequentially expressed genes control temporal and spatial specificity in aspergillus development.aspergillus nidulans brla, abaa, and weta form a dependent pathway that regulates asexual reproductive development. the order in which these genes are expressed determines the outcome of development. expression of brla in vegetative cells leads to activation of abaa and weta, cessation of vegetative growth, cellular vacuolization, and spore formation. by contrast, expression of abaa in vegetative cells does not result in conidial differentiation but does lead to activation of brla and weta, cess ...19892655931
the mitochondrial ribosomal rna molecules of aspergillus nidulans.the 16s and 23s mitochondrial rrnas of aspergillus nidulans have been identified by northern hybridisation and the ends of the molecules mapped onto the mitochondrial genome by s1 nuclease analysis. the results show that both the rrna molecules are longer than originally reported, forcing a reassessment of the potential secondary structures that can form in the terminal regions. in particular, structures resembling the 5.8s- and 4.5s-like domains of the bacterial large rrna can now be recognised ...19892656406
molecular characterization of the aspergillus nidulans ya locus.we investigated the molecular organization of the region of aspergillus nidulans chromosome i containing ya, a gene encoding the developmentally regulated enzyme conidial laccase. dna fragments were identified that complemented the ya2 mutation and were shown to correspond to ya by genetic mapping and gene disruption experiments. the molecular map of the region was oriented to the genetic map by testing dna fragments for their ability to complement a mutation in the tightly linked ade gene. the ...19892659435
isolation of a sexual sporulation hormone from aspergillus nidulans.psi factor is a substance produced by aspergillus nidulans that induces premature sexual sporulation. chromatographic analysis of psi-active extracts showed that psi activity resides in several different forms. two of the forms, psia1 and psib1, have been isolated and have been shown to have closely similar compositions. the most abundant form, psia1, reacts with alcohols in acidic solution by the addition of one entire molecule of the alcohol. this reaction, which is reversible, suggests that p ...19892661541
sterigmatocystin production on complex and defined substrates. 19892662007
nucleotide sequence of the aspergillus nidulans mitochondrial gene for subunit 5 of nadh dehydrogenase. 19892662141
the genetic analysis of mitosis in aspergillus nidulans.we describe here recent work on the molecular genetics of mitosis in the filamentous fungus aspergillus nidulans. aspergillus is one of three simple eukaryotes with powerful genetic systems that have been used to analyze mitosis. the modern molecular biological techniques available with this organism have made it possible to use mutations to identify genes and proteins that play an important role in mitosis. three aspergillus genes that affect mitosis are described. one gene, nima, is specifical ...19892662965
chromosomal mapping and gene disruption of the adhiii gene in aspergillus nidulans.there are at least three alcohol dehydrogenases in aspergillus nidulans. adhiii has no obvious physiological function. we describe here the cloning of the adhiii gene (alcc), its mapping on linkage group vii by "reverse genetics", and the properties of multicopy transformants tested for their ability to grow on a range of alcohols (butan-1-ol being the best substrate tested for growth). we were unable to detect any obvious alteration in phenotype of a strain carrying a disrupted copy of the adhi ...19892663191
developmentally related changes in the production and expression of endo-beta-1,4-glucanases in aspergillus nidulans.the production and electrophoretic expression of endoglucanase(s) were compared in the wild-type and three developmental mutants of aspergillus nidulans. in the wild type, the production of endoglucanase and its distribution in extracellular and intracellular fractions varied with the age of the culture and the yield was better in stable cultures (production of conidia and cleistothecia) as compared with shake cultures (vegetative hyphae only). two developmental mutants, aco-t69 and aco-40, whic ...19892663642
the proline transport protein of aspergillus nidulans is very similar to amino acid transporters of saccharomyces cerevisiae.in aspergillus nidulans, the gene prnb encoding the major proline transport system is one of a cluster of four genes necessary and sufficient for the utilization of proline as sole nitrogen and/or carbon source. the prn cluster has been cloned and the sequence and transcript map of the prnb gene are presented in this paper. the predicted translated sequence consists of 570 amino acids, resulting in a molecular weight of 63,028 daltons. its hydropathy profile shows 10 hydrophobic segments typical ...19892664423
cloning and physical characterization of the l-proline catabolism gene cluster of aspergillus nidulans.the proline catabolism gene cluster of aspergillus nidulans was cloned using a 'brute force' technique which detects clones hybridizing to restriction fragments overlapping chromosomal rearrangements. a number of deletion mutations and a translocation mutation in the cluster have been physically mapped, and an excellent correlation between the genetic and physical maps was established. transcripts have been identified and orientated for each of the four genes of the cluster. all are monocistroni ...19892668692
nucleotide sequence of the only unidentified reading frame in the aspergillus nidulans mitochondrial genome. 19892668894
electrophoretic karyotype of aspergillus nidulans.an electrophoretic karyotype of aspergillus nidulans has been obtained using contour-clamped homogeneous electric field gel electrophoresis. six chromosomal bands were separated, with two of the bands migrating as doublets. using the schizosaccharomyces pombe and saccharomyces cerevisiae chromosomes as size standards, we estimate the sizes of the chromosomes to be between 2.9 and 5.0 megabase pairs (mb) with a total genome size of approximately 31 mb. four of the eight genetic linkage groups wer ...19892668960
isolation and characterization of the 3-phosphoglycerate kinase gene (pgk) from the filamentous fungus trichoderma reesei.the 3-phosphoglycerate kinase gene (pgk) from trichoderma reesei was isolated by hybridization with the corresponding saccharomyces cerevisiae pgk gene. the 1,545 nt long nucleotide sequence of the cloned gene codes for a 416 amino acid protein. the coding sequence contains two introns of 219 and 75 nt, respectively, at positions identical to those corresponding genes from the other filamentous fungi aspergillus nidulans and penicillum chrysogenum. this gene codes for two mrnas of about 1.65 kb ...19892670282
characterization of the amdr-controlled lama and lamb genes of aspergillus nidulans.four aspergillus nidulans genes are known to be under the control of the trans-acting regulatory gene amdr. we describe the isolation and initial characterization of one of these amdr-regulated genes, lama. the lam locus, however, was found to consist of two divergently transcribed genes, the lama gene, and a new gene, also under amdr control, which we have designated lamb. using recombinant dna techniques we have constructed a strain of a. nidulans lacking a functional lamb gene. experiments co ...19892670667
a gene coding for the uric acid-xanthine permease of aspergillus nidulans: inactivational cloning, characterization, and sequence of a cis-acting mutation.in aspergillus nidulans, integration of transforming sequences can proceed through recombination with homologous sequences or at heterologous sites in the genome. in a strain with a large deletion in the gene coding for acetamidase (amds), a plasmid carrying this gene integrates into and inactivates uapa, the putative structural gene for uric acid-xanthine permease, with a frequency of 0.3%. the integration event occurs 3' to the open reading frame of amds. a 10-nucleotide sequence which occurs ...19892670668
cloning of the nitrate reductase gene (niad) of aspergillus nidulans and its use for transformation of fusarium oxysporum.an heterologous transformation system for the phytopathogenic fungus fusarium oxysporum has been developed based on the use of the aspergillus nidulans nitrate reductase gene (niad). f. oxysporum nia- mutants were easily selected by chlorate resistance. the a. nidulans niad gene was isolated from a gene library by complementation of an a. nidulans niad mutant. the cloned gene is capable of transforming f. oxysporum nia- mutants at a frequency of up to ten transformants per microgram of dna. sout ...19892670677
gene function identified by interspecific transformation.aspergillus nidulans is able to utilize 2-pyrrolidinone as a nitrogen source while two related aspergillus species, a. niger and a. terreus, cannot. mutations in the lama gene of a. nidulans prevent growth on 2-pyrrolidinone. a plasmid (plam7) has been isolated containing the a. nidulans lama gene and a divergently transcribed adjacent gene of unknown function. transformation of a. terreus with subclones of plam7 showed that both genes are essential for the utilization of a new nitrogen source, ...19892670678
a single, phosphate-repressible deoxyribonuclease, dnase a, secreted in aspergillus nidulans.high levels of nuclease activities were identified in filtrates of aspergillus cultures after growth in low-but not in high-phosphate media. deoxyribonuclease activities, characterized extensively by column chromatography, showed a coincident single peak for ss- and ds-dnase which was distinct from the peak for rnase. both ss-dnase and ds-dnase are endonucleolytic and showed the highest activity in the presence of ca2+ and mn2+ (at ph 8.0). they also showed identical heat sensitivities suggestin ...19892673210
transformation of seven species of filamentous fungi using the nitrate reductase gene of aspergillus nidulans.a gene transfer system originally developed for fusarium oxysporum has been applied to seven species of filamentous fungi of agricultural and industrial importance. this transformation system relies on the selection of mutants deficient in nitrate reductase by positive screening. such mutants were recovered easily in all the fungi tested--without mutagenic treatments--through their resistance to chlorate. they were transformed by a plasmid vector (pan301) carrying the aspergillus nidulans wild-t ...19892673557
cloning of the crea gene from aspergillus nidulans: a gene involved in carbon catabolite repression.the crea gene from a. nidulans has been cloned by complementation of a non-revertable mutant allele using a genomic library and marker rescue techniques. the rescued sequence was subcloned and a 2.3 kb fragment identified which complements several crea mutant alleles. northern analyses showed that crea encodes a transcript of approximately 1.8 kb in length and that the levels of this transcript varied by up to two fold depending on the carbon source. transformants containing more than two extra ...19892673558
characterization of an inducible expression system in aspergillus nidulans using alca and tubulin-coding genes.plasmids have been constructed in which expression of a gene can be placed under the control of the inducible promoter of the alca gene encoding alcohol dehydrogenase i in aspergillus nidulans. simplified shuttle vectors carrying pyr4 which complements pyrg89 mutations have also been constructed. these are based on puc19 and retain alpha-peptide expression. the beta-tubulin genes, tubc and bena, have been placed under the control of alca and their expression studied. levels of expression can be ...19892673931
disparate evolution of yeasts and filamentous fungi indicated by phylogenetic analysis of glyceraldehyde-3-phosphate dehydrogenase genes.genes encoding glyceraldehyde-3-phosphate dehydrogenase (ec 1.2.1.12) from several evolutionarily disparate organisms were used to construct a phylogenetic tree by evolutionary parsimony. the gapdh tree indicates that, in contrast to the presently accepted taxonomy of fungi, the yeasts saccharomyces cerevisiae and zygosaccharomyces rouxii evolved separately from the filamentous ascomycetes (such as aspergillus nidulans) with which these yeasts are classified. according to this tree, the saccharo ...19892674943
endochitinase from aspergillus nidulans implicated in the autolysis of its cell wall.an endochitinase from centrifuged autolyzed cultures of aspergillus nidulans has been purified 100 times. the enzyme has mw 27,000, pi of 4.8 units, ph optimum around 5 ph units. it is unstable at temperature greater than 70 degrees c and does not have a cation requirement. it is inhibited by hg2+, cu2+, ca2+ and ag+ and it does not have muramidase activity. the enzyme depolymerizes chitin rapidly with production of high molecular weight polysaccharides, and then slowly degrades these with produ ...19892676705
the highly divergent beta-tubulins of aspergillus nidulans are functionally interchangeable.an internal 1.4-kb bst eii fragment was used to disrupt the bena gene and establish heterokaryons. the heterokaryons demonstrated that the molecular disruption of bena results in a recessive bena null mutation. conidia from a heterokaryon swell and germinate but cannot undergo nuclear division and are thus inviable. a chimeric beta-tubulin gene was constructed with the bena promoter driving the tubc structural gene. this chimeric gene construction was placed on a plasmid containing a selectable ...19892681229
isolation and analysis of the acetate regulatory gene, facb, from aspergillus nidulans.the facb gene of aspergillus nidulans is thought to be involved in acetate induction of enzymes required for acetate utilization and of the acetamidase encoded by the multiply regulated amds gene. in addition, some evidence suggests that the facb gene has a structural as well as a regulatory role in acetate metabolism. the facb gene was cloned from a cosmid library by complementation of the facb101 loss-of-function mutation. transformants receiving multiple copies of facb displayed stronger grow ...19892685573
aspergillus findings in aids patients suffering from cryptococcosis.because of the known pathogenicity of cryptococcus neoformans and of aspergilli depending on defined but different immunodeficiencies of the host, the evaluation of their simultaneous cultural detection in specimens of the respiratory tract of aids patients is of epidemiological, diagnostic, pathogenetic and therapeutic interest. in 10 out of 15 aids patients the following species of the genus aspergillus could be isolated either once or repeatedly during the course of cr. neoformans infections ...19892685598
a gene transfer system based on the homologous pyrg gene and efficient expression of bacterial genes in aspergillus oryzae.a homologous transformation system for aspergillus oryzae is described. the system is based on an a. oryzae strain deficient in orotidine-5'-phosphate decarboxylase (pyrg) and the vector pao4-2, which contains a functional a. oryzae pyrg gene as selection marker. transformation of the a. oryzae pyrg mutant with circular pao4-2 resulted in the appearance of pyr+ transformants at a frequency of up to 20 per micrograms of dna, whereas with linear pao4-2 up to 200 transformants per micrograms dna we ...19892688930
a comparative study on ethanol and acetaldehyde as inducers of chromosome malsegregation in aspergillus nidulans.the activity of ethyl alcohol and acetaldehyde on mitotic chromosome segregation and conidial germination in aspergillus nidulans was studied. ethanol effectively induced malsegregation in a narrow range of concentrations (4.5-5.5%, v/v) and was inactive at doses which arrested conidial germination (above 6%). the same bell-shaped dose-response curve was shown by the spindle poison chloral hydrate, which was active in the range 6-10 mm. acetaldehyde displayed a diphasic dose-response curve. gene ...19892689879
cloning and characterization of the trpc gene from an aflatoxigenic strain of aspergillus parasiticus.the trpc gene in the tryptophan biosynthetic pathway was isolated from an aflatoxigenic aspergillus parasiticus by complementation of an escherichia coli trpc mutant lacking phosphoribosylanthranilate isomerase (prai) activity. the cloned gene complemented an e. coli trpc mutant deficient in indoleglycerolphosphate synthase (igps) activity as well as an aspergillus nidulans mutant strain that was defective in all three enzymatic activities of the trpc gene (glutamine amidotransferase, igps, and ...19892690735
rhizoxin resistant mutants with an altered beta-tubulin gene in aspergillus nidulans.rhizoxin and ansamitocin p-3 (a maytansinoid compound), potent inhibitors of mammalian brain tubulin assembly, inhibit growth of a variety of fungi including aspergillus nidulans. mutants of a. nidulans, bena10 which is a benomyl resistant beta-tubulin gene mutant and tuba1 which is a benomyl supersensitive alpha-tubulin gene mutant, were both sensitive to rhizoxin and ansamitocin p-3 to the same extent as wild-type strains. we isolated 18 rhizoxin resistant mutants of a. nidulans. all of these ...19892691873
rna-mediated genetic transformation in aspergillus nidulans.we developed a model-system for correcting genetic alterations of an aspergillus nidulans strain (ribo, paba, bio, w, acr) by treating protoplasts with total rna extracted from another a. nidulans strain bearing wild type alleles for the same genetic markers. the results revealed the occurrence of a true genetic transformation. the phenomenon was rna-dependent since it was abolished by pancreatic ribonuclease treatment. the term retrotransformation is proposed since the rna messages artificially ...19892692827
beta-n-acetylglucosaminidase from aspergillus nidulans which degrades chitin oligomers during autolysis.a hexosaminidase from autolyzed cultures of aspergillus nidulans was purified 196 fold and characterized as a beta-n-acetylglucosaminidase (ec 3.2.1.30). the enzyme has a mw of 190000, a pi of 4.3, and optimum ph of 5.0 and is unstable at temperatures above 50 degrees c. the enzyme is a glycoprotein with 19.5% sugars, mannose being the principal component. it binds strongly to chitin. the enzyme hydrolyzes different substrates. the ki with the competitive inhibitor 2-acetamido-2-deoxy-d-gluconol ...19892693201
genetic transformation of the filamentous yeast, trichosporon cutaneum, using dominant selection markers.an efficient transformation system for the filamentous yeast, trichosporon cutaneum, has been developed. transformation was obtained with plasmids carrying either the escherichia coli hygromycin b phosphotransferase-encoding gene (hph) or the streptoalloteichus hindustanus phleomycin-resistance gene (ble), as dominant selection markers. expression of both resistance-conferring genes was controlled by the gpd promoter and the trpc terminator, from aspergillus nidulans. the transformation frequenc ...19892693213
characterization of purine hydroxylase i from aspergillus nidulans.purine hydroxylase i from aspergillus nidulans was purified 850-fold. the purified preparations exhibited the spectral and catalytic properties, including broad specificity for oxidizing and reducing substrates, typical of molybdenum/flavin/iron-sulphur-containing hydroxylases (oxotransferases).19892693595
immunochemical assay applied to mycotoxin biosynthesis: elisa comparison of sterigmatocystin production by aspergillus versicolor and aspergillus nidulans.conventional thin layer and instrumental methods for analyzing mycotoxins and their precursors are time-consuming and make the investigation of mycotoxin biosynthesis particularly difficult. as an alternative, sensitive enzyme-liked immunosorbent assays (elisas) can be utilized to analyze for these compounds. in this report, sterigmatocystin production in test tube cultures of aspergillus versicolor atcc 18643 and aspergillus nidulans atcc 32610 were compared using competitive elisa. polyclonal ...19892693965
on the mechanisms of induced aneuploidy in aspergillus nidulans and validation of tests for genomic mutations. 19892696976
[relation of bronchial asthma and allergic bronchopulmonary aspergillosis].an allergological examination was conducted in 30 out of 83 (36.07%) patients showing symptoms of bronchial asthma. it was found that skin hypersensitivity to aspergilla allergens coupled with a high serum ige level. the appropriateness of such affection referral to a separate nosological entity (allergic bronchopulmonary aspergillosis) is under discussion.19892697785
aspergillus nidulans as a test organism for the detection of chemically-induced mitotic crossing-over and chromosome malsegregation.the genetic systems developed in the mould aspergillus nidulans to study the chemical induction of mitotic genetic segregation were used to investigate the mechanism of aneuploidy induction by the main benzene hydroxy metabolites. detailed genetic analysis of mitotic segregants produced by individual colonies revealed the simultaneous occurrence of both whole chromosome segregants and mitotic cross-overs, i.e. a pattern not compatible with the induction of numerical abnormalities as the primary ...19892698601
keratinolytic fungi of wadi qena in egypt.forty-six soil samples collected from different sites of wadi qena were examined for keratinophilic fungi using the hair baiting technique. thirty-two species in addition to one variety of each of a. nidulans and a. flavus which belong to eighteen genera were recovered. aspergillus, chrysosporium, penicillium, microsporum and fusarium were the most frequent genera developed from baited soils.19892707686
partial characterization of the gene coding for subunit iv of soybean mitochondrial nadh dehydrogenase.by using the spinach chloroplast atpe gene (epsilon-subunit coding gene) as a probe we have isolated, from a soybean mitochondrial dna library, a sequence containing a 405 base-pairs (bp) open-reading frame (orf). this orf, which is unique in the soybean mitochondrial genome, is probably part of an exon of the gene coding for subunit iv of the nadh dehydrogenase complex. the predicted protein shows 42% sequence similarity with the c-terminal region the aspergillus nidulans nad4 protein. the gene ...19892743433
improved transformation efficiency of aspergillus niger using the homologous niad gene for nitrate reductase.aspergillus niger transformation frequencies of up to 1,176 transformants per micrograms dna were achieved using the plasmid vector psta10 containing the a. niger nitrate reductase structural gene. analysis of genomic endonuclease cleaved dna from nitrate utilising transformants by dna hybridisation, showed that most integration events are as a result of homologous recombination. the niad transformation system was used successfully for the introduction of the unselected escherichia coli fusion g ...19892791035
a large cluster of highly expressed genes is dispensable for growth and development in aspergillus nidulans.we investigated the functions of the highly expressed, sporulation-specific spoc1 genes of aspergillus nidulans by deleting the entire 38-kb spoc1 gene cluster. the resultant mutant strain did not differ from the wild type in (1) growth rate, (2) morphology of specialized reproductive structures formed during completion of the asexual or sexual life cycles, (3) sporulation efficiency, (4) spore viability or (5) spore resistance to environmental stress. thus, deletion of the spoc1 gene cluster, r ...19892471671
enhancement of aspergillus nidulans transformation by the ans1 sequence.we have shown that the aspergillus nidulans ans1 sequence enhances the efficiency of transformation when introduced into vectors containing argb or trpc genes. increased efficiency of transformation is also observed when ans1 is present on a second cotransforming plasmid. in an attempt to explains the ans1 transactivity we have performed analysis of some cotransformants.19892484740
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