TitleAbstractYear(sorted ascending)
photosynthetic fractionation of the stable isotopes of oxygen and carbon.isotope discrimination during photosynthetic exchange of o2 and co2 was measured using enzyme, thylakoid, and whole cell preparations. evolved oxygen from isolated spinach thylakoids was isotopically identical (within analytical error) to its source water. similar results were obtained with anacystis nidulans richter and phaeodactylum tricornutum bohlin cultures purged with helium. for consumptive reactions, discrimination ([delta], where 1 + [delta]/1000 equals the isotope effect, k16/k18 or k1 ...199312231663
mitotic catastrophe is the mechanism of lethality for mutations that confer mutagen sensitivity in aspergillus nidulans.we have examined the consequences of treatment with dna-damaging agents of uvs mutants and the bimd6 mutant of aspergillus nidulans. we first established that wild-type aspergillus undergoes a cell cycle delay following treatment with the dna-damaging agents methyl methanesulfonate (mms) or ultraviolet light (uv). we have also determined that strains carrying the bimd6, uvsb110, uvsh77, uvsf201 and the uvsc114 mutations, all of which cause an increased sensitivity to dna-damaging agents, undergo ...19947506362
isolation and characterization of sexual spore pigments from aspergillus nidulans.the homothallic ascomycete aspergillus nidulans produces two types of pigmented spores: conidia and ascospores. the synthesis and localization of the spore pigments is developmentally regulated and occurs in specialized cell types. on the basis of spectroscopic evidence, we propose that the major ascospore pigment of a. nidulans (ascoquinone a) is a novel dimeric hydroxylated anthraquinone. the structure of ascoquinone a, as well as a comparison to model compounds, suggests that it is the produc ...199416349224
active-site histidines in recombinant cyanobacterial ribulose-1,5-bisphosphate carboxylase/oxygenase examined by site-directed mutagenesis.the functions of his(291), his(295) and his(324) at the active-site of recombinant a. nidulans ribulose-1,5-bisphosphate carboxylase/ oxygenase have been explored by site-directed mutagenesis. replacement of his(291) by k or r resulted in unassembled proteins, while its replacement by e, q or n resulted in assembled but inactive proteins. these results are in accord with a metal ion-binding role of this residue in the activated ternary complex by analogy to x-ray crystallographic analyses of tob ...199424310117
two novel deduced serine/threonine protein kinases from saccharomyces cerevisiae.we have cloned genes for two closely related protein kinase (pk) homologues from saccharomyces cerevisiae. sequence alignment of the kinase domain with previously characterized pk reveals the highest degree of similarity with second messenger-regulated kinases. rck1 encodes a 58-kda protein, and is weakly expressed. rck2 encodes a 65-kda protein, and transcripts from this gene are readily detected. rck1 has been mapped to the l arm of chromosome vii, and rck2 to chromosome xii. disruption of the ...19948112585
induction of pseudohyphal growth by overexpression of phd1, a saccharomyces cerevisiae gene related to transcriptional regulators of fungal development.when starved for nitrogen, mata/mat alpha cells of the budding yeast saccharomyces cerevisiae undergo a dimorphic transition to pseudohyphal growth. a visual genetic screen, called phd (pseudohyphal determinant), for s. cerevisiae pseudohyphal growth mutants was developed. the phd screen was used to identify seven s. cerevisiae genes that when overexpressed in mata/mat alpha cells growing on nitrogen starvation medium cause precocious and unusually vigorous pseudohyphal growth. phd1, a gene whos ...19948114741
transport of lactate and its regulation in saccharomyces cerevisiae mutants deficient in specific metabolic steps. 19948550003
genetic and molecular characterisation of purine permease genes of aspergillus nidulans reveals a novel family of transporters conserved in prokaryotes and eukaryotes.the ascomycete fungus aspergillus nidulans can utilize purines (adenine, guanine, hypoxanthine, xanthine, and uric acid) as sole nitrogen sources [1]. the expression of most structural genes involved in the pathway of purine uptake and catabolism is subject to uric acid induction, mediated by the product of the positive regulatory gene uay, and to nitrogen metabolite repression, mediated by the product of the general, positive-acting, gata-like transcription factor, encoded by the area gene [1].19948550005
structure-function analysis of the proline permease (prnb) of the filamentous fungus aspergillus nidulans. 19948550020
two different, adjacent and divergent zinc finger binding sites are necessary for crea-mediated carbon catabolite repression in the proline gene cluster of aspergillus nidulans.crea is the negative regulator mediating carbon catabolism repression in aspergillus nidulans. we have determined all the sites in the dna region between the prnd and prnb genes of the proline degradation cluster of this organism which are able to bind a fusion protein containing the zinc finger domain of crea. the consensus sequence derived for crea binding is 5'-syggrg-3', but not all possible sites derived from this consensus do in fact bind. the binding of at least some sequences of the form ...19948313886
direct analysis of native and chimeric gata specific dna binding proteins from aspergillus aspergillus nidulans the regulatory gene area is responsible for mediating nitrogen metabolite repression. the area product (area) represents an example of the gata family of dna binding proteins, which are characterised by the presence of a gata domain consisting of a zinc finger within a highly conserved region of 52 amino acids. among the other transcription factors included in this family is the principal erythroid transcription factor, gata-1, which contains two gata domains. in order to ...19947816601
isolation and characterization of an aspergillus nidulans gene encoding an alkaline protease.we have cloned an aspergillus nidulans gene (prta) encoding an alkaline protease (alp) by probing an a. nidulans library with a fragment amplified from an aspergillus oryzae alp-encoding gene. the nucleotide (nt) sequence of prta was determined. the structure of prta is similar to that of the a. oryzae alp-encoding gene. the prta gene is composed of four exons which are separated by three introns of 59, 57 and 54 nt. the deduced amino acid sequence of the prta product shows a high degree of simi ...19947821793
sexual origins of british aspergillus nidulans isolates.aspergillus nidulans is a holomorphic fungus, capable of producing both meiotically and mitotically derived spores. meiosis may be an evolutionary relic in this species because it is potentially capable of mitotic recombination and because most aspergilli lack the ability to produce meiotic spores. we tested the null hypothesis that meiosis has been a major factor in the origin of strains of a. nidulans from great britain by estimating linkage disequilibrium among restriction fragment length pol ...19947907796
isolation of the faca (acetyl-coa synthetase) gene of phycomyces blakesleeanus.a 5.6 kb dna fragment from the fungus phycomyces blakesleeanus has been cloned and sequenced. the fragment contains a gene that probably codes for the enzyme acetyl-coenzyme a synthetase (faca). the amino acid sequence deduced for the p. blakesleeanus protein is highly homologous to those of acetyl-coa-synthetases from other organisms. when placed under the control of a constitutive promoter from aspergillus nidulans, the cloned gene complemented a faca- mutation of this organism. in p. blakesle ...19947914670
assignment of rflp, rapd and isoenzyme markers to aspergillus nidulans chromosomes, using chromosome-substituted segregants of a hybrid of a. nidulans and a. quadrilineatus.chromosome-substituted haploid segregants were selected from among the benomyl-induced progeny of an interspecific hybrid produced by polyethylene-glycol-induced fusion of protoplasts of an aspergillus nidulans 'master strain' and an a. quadrilineatus auxotrophic mutant. these segregants were examined by rflp, rapd, and isoenzyme analysis. the a. nidulans ribosomal repeat unit was assigned to chromosome v, while the bena and the pyrg genes were assigned to linkage groups viii and i, respectively ...19947915967
in vitro binding of the two-finger repressor crea to several consensus and non-consensus sites at the ipna upstream region is context dependent.the two zinc-fingers of the aspergillus nidulans repressor crea recognize the consensus hexanucleotide 5'-syggrg-3'. we have determined all the crea binding sites in a approximately 2 kb region upstream the ipna gene. our analysis shows that (i) crea binds to certain consensus sites in a context-dependent manner; (ii) five non-consensus 6-bp sequences are also recognized by crea; this non-canonical binding correlates with the presence of a second, neighbouring crea binding site, suggesting that ...19948143847
identification and characterization of aspergillus nidulans mutants defective in cytokinesis.filamentous fungi undergo cytokinesis by forming crosswalls termed septa. here, we describe the genetic and physiological controls governing septation in aspergillus nidulans. germinating conidia do not form septa until the completion of their third nuclear division. the first septum is invariantly positioned at the basal end of the germ tube. block-and-release experiments of nuclear division with benomyl or hydroxyurea, and analysis of various nuclear division mutants demonstrated that septum f ...19948150280
homologs of the yeast neck filament associated genes: isolation and sequence analysis of candida albicans cdc3 and cdc10.morphogenesis in the yeast saccharomyces cerevisiae consists primarily of bud formation. certain cell division cycle (cdc) genes, cdc3, cdc10, cdc11, cdc12, are known to be involved in events critical to the pattern of bud growth and the completion of cytokinesis. their products are associated with the formation of a ring of neck filaments that forms at the region of the mother cell-bud junction during mitosis. morphogenesis in candida albicans, a major fungal pathogen of humans, consists of bot ...19948152419
homology at the amino acid level between plant phytochromes and a regulator of asexual sporulation in emericella (= aspergillus) nidulans.protein sequence comparison between the n-terminal regions of the brla (bristle a) protein of the ascomycete fungus aspergillus nidulans and a number of plant phytochromes has demonstrated a moderate level of sequence similarity. the region of similarity corresponds to the phytochrome domains believed to be responsible for photoreception and which undergo light-induced conformational changes, although a putative chromophore-binding site is not evident. over 22% of residues are conserved and 24% ...19948165242
microtubule organizing centers and gamma-tubulin.the polar assembly of cellular microtubules is organized by microtubule organizing centers (mtocs). eukaryotic cells across different species, and different cell types within single species, have morphologically diverse mtocs, which have the common function of organizing microtubule arrays by initiating microtubule assembly and anchoring microtubules by their slow-growing 'minus' ends, thus ensuring that the rapidly growing 'plus' ends extend distally. the past few years have witnessed a variety ...19948167026
characterization of a 3-dehydroquinase gene from actinobacillus pleuropneumoniae with homology to the eukaryotic genes qa-2 and qute.a gene was cloned from actinobacillus pleuropneumoniae strain 4074 by complementation of an arod strain of escherichia coli. the e. coli gene arod codes for a 3-dehydroquinase enzyme of type i, active in the aromatic biosynthesis pathway. the a. pleuropneumoniae gene, termed aroq, displays no base or amino acid sequence homology to arod of e. coli. it is instead homologous to the qute and qa-2 genes, respectively of aspergillus nidulans and neurospora crassa. these genes code for 3-dehydroquinas ...19948170389
identification of nitrate transporter genes in chlamydomonas reinhardtii.the chlamydomonas reinhardtii nar-2, nar-3, and nar-4 genes, which are within a nitrate-regulated gene cluster containing the nitrate reductase structural gene nit-1, have been related to nitrate transport. mutant strains defective in nitrate transport and having an active nitrate reductase have been genetically constructed. their nitrate non-utilizing phenotype has been directly complemented by transformation using the pco-5 plasmid which carries the nar-2, nar-3, and nar-4 clustered genes. int ...19948180624
expression of the noncatalytic domain of the nima kinase causes a g2 arrest in aspergillus nidulans.temperature-sensitive mutation of the nima gene of aspergillus nidulans causes a reversible g2 arrest, whereas overexpression of nima causes premature entry into mitosis from which the cells cannot exit. the nima gene encodes a ser/thr-specific protein kinase (nima) which contains an extended cooh-terminal noncatalytic domain. to evaluate the role of this enzyme in nuclear division control, we introduced various mutant nima cdnas under the control of the inducible alcohol dehydrogenase gene prom ...19948187763
variability of aspergillus nidulans antigens with media and time and temperature of growth.the influence of culture medium and time and temperature of growth on the appearance of aspergillus nidulans antigens was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by silver staining or western blot (immunoblot), of the proteins present in total cellular extracts or culture supernatants. samples in the exponential, deceleration, and stationary growth phases were selected by biochemical, morphological, and ultrastructural criteria. protein and antigen patte ...19948188355
expression of the 3-phosphoglycerate kinase gene (pgka) of penicillium chrysogenum.the sequence of the penicillium chrysogenum pgka gene promoter was determined up to 952 nucleotides (nt) 5' to the major transcriptional start point (position +1), and contains a 38 bp pyrimidine-rich region within which transcription initiates at this and two minor sites (-11, -23). a 21 bp segment (-99 to -79) closely matches a region which is essential for the expression of the aspergillus nidulans pgka gene. a further region was found with similarity to sequences in other a. nidulans promote ...19948190080
cloning and characterisation of the cytochrome c gene of aspergillus nidulans.the cytochrome c gene (cyca) of the filamentous fungus aspergillus nidulans has been isolated and sequenced. the gene is present in a single copy per haploid genome and encodes a polypeptide of 112 amino acid residues. the nucleotide sequence of the a. nidulans cyca gene shows 87% identity to the dna sequence of the neurospora crassa cytochrome c gene, and approximately 72% identity to the sequence of the saccharomyces cerevisiae iso-1-cytochrome c gene (cyc1). the s. cerevisiae cyc1 gene was us ...19948277943
relationship between zinc content and dna-binding activity of the dna-binding motif of the transcription factor alcr in aspergillus nidulans.the transcription factor alcr of the ethanol utilisation pathway in aspergillus nidulans contains a zinc binuclear motif (cysx2cysx6cysx16cysx2cysx6cys), within the dna-binding domain located in the n-terminal region of the alcr protein. specific targets have been localised in the promoter of the alcr gene, involved in the autoregulation process, and in the promoter of the structural gene alca (encoding alcohol dehydrogenase i), which is also under the control of alcr. the dna-binding domain has ...19948277945
analysis of the regulation of penicillin biosynthesis in aspergillus nidulans by targeted disruption of the acva analyse the regulation of the biosynthesis of the secondary metabolite penicillin in aspergillus nidulans, a strain with an inactivated acva gene produced by targeted disruption was used. acva encodes delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine synthetase (acvs), which catalyses the first step in the penicillin biosynthetic pathway. to study the effect of the inactivated acva gene on the expression of acva and the second gene, ipna, which encodes isopenicillin n synthase (ipns), a. nidul ...19948277946
identification of substrate specificity determinants for the cell cycle-regulated nima protein kinase.nima is a cell cycle-regulated protein kinase required for the g2/m transition in the filamentous fungus aspergillus nidulans. previous biochemical characterization of the recombinant enzyme indicated that nima is a protein serine/threonine specific kinase with beta-casein being the best substrate from the many proteins and peptides tested (lu, k.p., osmani, s.a., and means, a.r. (1993) j. biol. chem. 268, 8769-8776). however, substrate specificity or physiologically relevant substrates for nima ...19948120013
an "instant gene bank" method for heterologous gene cloning: complementation of two aspergillus nidulans mutants with gaeumannomyces graminis dna.we present a novel technique for gene cloning by complementation of mutations in aspergillus nidulans with dna from a heterologous organism, gaeumannomyces graminis. this technique bypasses the time-consuming and difficult construction of gene libraries, making it both rapid and simple. the method relies on recombination between a fungal replicating vector phelp1 and linear g. graminis genomic dna during co-transformation. we were able to complement two out of seven a. nidulans mutants tested an ...19948121400
an 'instant gene bank' method for gene cloning by mutant complementation.we describe a new method of gene cloning by complementation of mutant alleles which obviates the need for construction of a gene library in a plasmid vector in vitro and its amplification in escherichia coli. the method involves simultaneous transformation of mutant strains of the fungus aspergillus nidulans with (i) fragmented chromosomal dna from a donor species and (ii) dna of a plasmid without a selectable marker gene, but with a fungal origin of dna replication ('helper plasmid'). transform ...19948121403
regulation of the expression of the isocitrate lyase gene (acud) of aspergillus nidulans.analysis of the promoter region of the acetate-induced isocitrate lyase gene (acud) of aspergillus nidulans is described. transcription start sites were detected at positions -163, -170 and approximately -281 upstream of the atg. transcription analysis showed that the acud gene is transcribed during growth on acetate but not on hexoses or glycerol. expression of the acud gene was studied under inducing and repressing conditions in cre+, crea, creb and crec mutant strains, showing that the crea(d ...19948121406
alpha-l-arabinofuranosidase production by aspergillus nidulans.the effects of some physico-chemical parameters on production of extracellular alpha-l-arabinofuranosidase by aspergillus nidulans were examined. highest levels of alpha-l-arabinofuranosidase were generated with cultures grown on 1% (w/v) purified beet pulp arabinan at 30 degrees c and at an initial ph of 7.0. the enzyme was shown to be very sensitive to the action of proteases. zymogram overlay of a protein profile obtained by sds-page revealed the occurrence of a band (m(r) 36,000) exhibiting ...19948125239
at least three genes are responsible for benomyl-resistance in metarhizium anisopliae.four benomyl-resistant mutants isolated from metarhizium anisopliae were 10 to 500 times more resistant than the original mt strain. the resistance markers analysed in three of these mutants were due to three different mutations and no additive effect of these genes was observed in double mutants. the four mutants presented normal conidiation in the presence or absence of benomyl and no sensitivity or resistance to temperature. probably m. anisopliae has a mechanism of benomyl resistance differi ...19948127229
cytoplasmic dynein is involved in nuclear migration in aspergillus nidulans.nuclear migration plays an important role in the growth and development of many organisms including the multinuclear fungus aspergillus nidulans. we have identified four genes, nuda, nudc, nudf, and nudg, in which temperature-sensitive mutations affect nuclear distribution. in this report, we describe the cloning of the nuda gene by complementation of the mutant phenotype by using a chromosome viii-specific cosmid library. a genomic fragment of nuda hybridized to an mrna of approximately 14 kb. ...19948134356
the alcohol dehydrogenase gene adh1 is induced in aspergillus flavus grown on medium conducive to aflatoxin aspergillus flavus cdna library was screened by differential hybridization to isolate clones corresponding to genes that are actively transcribed under culture conditions conducive to aflatoxin biosynthesis. one clone with a 1.28-kb insert was isolated, and its nucleotide sequence was determined. the nucleotide sequence of this clone had 75% dna identity to those of the alcohol dehydrogenase genes from aspergillus nidulans, and the putative polypeptide translated from the cdna sequence had 82 ...19948135521
the aspergillus nidulans abaa gene encodes a transcriptional activator that acts as a genetic switch to control development.the aspergillus nidulans abaa gene encodes a protein containing an atts dna-binding motif and is required for the terminal stages of conidiophore development. results from gel mobility shift and protection, missing-contact, and interference footprint assays showed that abaa binds to the sequence 5'-cattcy-3', where y is a pyrimidine, making both major- and minor-groove contacts. multiple abaa binding sites are present in the cis-acting regulatory regions of several developmentally controlled str ...19948139553
isolation and characterization of cdna and genomic promoter region for a heat shock protein 30 from aspergillus nidulans.a cdna encoding for a heat shock protein 30 (hsp30) of aspergillus nidulans and the promoter region of its gene were analyzed for their primary structures. the promoter region had no heat shock element but possessed three inverted repeat sequences. northern blot hybridization indicated that the expression of the hsp30 gene was high at a normal temperature and was slightly accelerated at elevated temperatures in a. nidulans cells. although the deduced amino acid sequence of the a. nidulans hsp30 ...19947918658
mitochondrial dna restriction fragment length polymorphisms in field isolates of the aspergillus niger aggregate.the mitochondrial dnas (mtdnas) and the ribosomal repeat unit (ribosomal dna, rdna) of black aspergillus isolates collected in various parts of the world were examined. wide-ranging mtdna variation was observed in natural populations of the aspergillus niger aggregate. most isolates were classifiable as a. niger or aspergillus tubingensis according to their rdna and mtdna patterns. the mtdna variation was distributed unevenly in the populations studied. the mtdnas of most of the isolates collect ...19947922884
phenotypic and epistatic grouping of hypo- and hyper-rec mus mutants in aspergillus.the mutants musk to muss of aspergillus nidulans are sensitive to methyl-methanesulfonate (mms) and several of them are meiotic-defective and alter mitotic recombination frequencies. all were found to be cross-sensitive to 4-nitro-quinoline-n-oxide (4-nqo) but unexpectedly none of them was hypersensitive to gamma-rays and few to uv light. double mus; uvs mutants were constructed to test for interactions with uvs mutations of the four epistatic groups of aspergillus, "uvsf", "uvsc", "uvsi", and " ...19947923408
the aspergillus nidulans flug gene is required for production of an extracellular developmental signal and is related to prokaryotic glutamine synthetase i.mutations in the aspergillus nidulans flug gene disrupt the programmed induction of asexual sporulation and result in formation of fluffy colonies that are characterized by undifferentiated cotton-like masses of vegetative cells. we show that the flug mutant phenotype is suppressed when flug mutant colonies are grown next to wild-type colonies even if the two strains are separated by dialysis membrane with a 6000- to 8000-dalton pore size. flug encodes a cytoplasmically localized approximately 9 ...19947926755
rodletless mutants of aspergillus fumigatus.conidia of aspergillus fumigatus adhere in vitro to host proteins and cells via the outer cell wall layer. the roda gene of a. fumigatus was cloned by homology with the roda gene of aspergillus nidulans, which is involved in the structure of the rodlets characteristic of the surface layer. the a. fumigatus roda protein sequence has 85% similarity to that of a. nidulans roda; the sequence codes for a hydrophobin, a low-molecular-weight protein moderately hydrophobic and rich in cysteines. the gen ...19947927699
hyp1, a hydrophobin gene from aspergillus fumigatus, complements the rodletless phenotype in aspergillus nidulans.aspergillus fumigatus produces conidia that are highly dispersable and resistant to degradation. we have sought to analyze these properties by studying the rodlets which form the outer spore coat protein. degenerate primers based on hydrophobins in other fungi were applied to genomic dna from a. fumigatus in pcr. a product of this reaction with similarity to an aspergillus nidulans gene as judged by southern hybridization was chosen for further study. cloning and sequencing revealed a gene with ...19947927700
a novel murine gene encoding a 216-kda protein is related to a mitotic checkpoint regulator previously identified in aspergillus nidulans.we describe the isolation and characterization of a novel mouse gene, tsg24, which displays striking sequence similarities to the aspergillus nidulans bime gene. the bime gene has been shown to be a mitotic checkpoint regulator, negatively regulating entry into mitosis in a. nidulans. the tsg24 gene was found to contain a long open reading frame of 1944 amino acids, encoding a polypeptide with a calculated molecular mass of 216,087 da. we have developed an antibody directed against the product o ...19947929068
general primer-mediated pcr for detection of aspergillus species.a pcr assay was developed for the diagnosis of invasive aspergillosis in immunocompromised patients. for this purpose, the complete nucleotide sequences of the genes encoding the 18s rrna of aspergillus nidulans, aspergillus terreus, aspergillus niger, and aspergillus flavus were elucidated and aligned to the sequences of aspergillus fumigatus and other clinically relevant prokaryotic and eukaryotic microorganisms. genus-specific sequences could be identified in the v7 to v9 region of 18s rrna. ...19947929762
heterologous expression of the cytotoxin restriction in aspergillus nidulans and aspergillus niger.the cdna clone of restrictocin was placed under the control of the glucoamylase promoter from aspergillus awamori and was transformed into aspergillus nidulans and aspergillus niger. site-specific changes were introduced into cdna constructs and these were transformed into a. nidulans. the secretion signal sequence was deleted from one form of the gene and three mutations introduced single amino acid substitutions into the protein. culture conditions were optimized for maximum expression levels ...19947827506
overexpression of flba, an early regulator of aspergillus asexual sporulation, leads to activation of brla and premature initiation of development.aspergillus nidulans reproduces asexually by forming thousands of mitotically derived spores atop highly specialized multicellular organs termed conidiophores. we have identified a gene called flba (for fluffy low brla expression) that is required for initiation of a. nidulans conidiophore development. flba mutants form abnormal colonies that have a distinct fluffy phenotype characterized by tightly interwoven aerial hyphae that autolyse as the colony matures. the requirement for flba in conidio ...19947830576
two new genes involved in signalling ambient ph in aspergillus nidulans.two new genes, palh and pali, where mutations mimic the effects of acidic growth ph have been identified in aspergillus nidulans. a palh mutation is phenotypically indistinguishable from mutations in the pala, palb, palc, and palf genes, whereas pali mutations differ only in that they allow some growth at ph 8. mutations in pala, b, c, f, and h are epistatic to a pali mutation and the significance of this epistasis is discussed. additionally, pale and palb mutations have been shown to be allelic ...19947830727
glucose-induced inactivation of isocitrate lyase in aspergillus nidulans.the existence of a second mechanism of catabolite control of isocitrate lyase of aspergillus nidulans, in addition to the carbon catabolite repression phenomenon recently reported was analysed. isocitrate lyase was rapidly and specifically inactivated by glucose. the inactivation was irreversible at all stages in the presence of cycloheximide, showing that reactivation depends on de novo protein synthesis. in addition, analysis of glucose-induced inactivation of isocitrate lyase in a cread-30 st ...19947872837
extracellular arabinases in aspergillus nidulans: the effect of different cre mutations on enzyme levels.the regulation of the syntheses of two arabinan-degrading extracellular enzymes and several intracellular l-arabinose catabolic enzymes was examined in wild-type and carbon catabolite derepressed mutants of aspergillus nidulans. alpha-l-arabinofuranosidase b, endoarabinase, l-arabinose reductase, l-arabitol dehydrogenase, xylitol dehydrogenase, and l-xylulose reductase were all inducible to varying degrees by l-arabinose and l-arabitol and subject to carbon catabolite repression by d-glucose. wi ...19947872840
cointegration of transforming dnas in aspergillus nidulans: a model using autonomously-replicating plasmids.transforming dnas form cointegrates in aspergillus nidulans by homologous and non-homologous recombination as well as by end-to-end ligation of linear fragments. this process has been studied by means of a model in which the linkage of a marker gene to the origin of autonomous replication ama1 was selected for. recombinant plasmids were rescued into escherichia coli and subjected to restriction mapping and sequence analysis. it was shown that circular dna molecules recombined predominantly withi ...19947882430
high-level expression of human superoxide dismutase in the cyanobacterium anacystis nidulans 6301.a chemically synthesized gene encoding human cuzn superoxide dismutase (hsod) was cloned into the shuttle vector pbax18r and expressed in anacystis nidulans 6301 (synechococcus sp. strain pcc 6301) under the control of a ribulose-1,5-bisphosphate carboxylase/oxygenase gene (rbc) promoter derived from a. nidulans 6301. the sequences immediately upstream from the hsod coding region and the distances between the ribosomal binding site and atg initiation codon strongly affected the expression of the ...19947937873
rescue of yeast defective in mitochondrial atp synthase subunit 8 by a heterologous gene from aspergillus nidulans.mitochondrial atp synthase subunit 8 of the yeast saccharomyces cerevisiae and of the filamentous fungus aspergillus nidulans have the same length and similar structural motifs. however, the two proteins share only 50% identical residues, with the conserved residues being concentrated in the n- and c-terminal domains. we have investigated whether it is amino acid sequence or overall structural motifs that are required for subunit 8 function. pcr was used to construct a gene encoding a. nidulans ...19947945306
an analysis of the sequence of part of the right arm of chromosome ii of s. cerevisiae reveals new genes encoding an amino-acid permease and a carboxypeptidase.we have analysed two new genes, ybr1007 and ybr1015, discovered during the systematic sequencing of chromosome ii of s. cerevisiae. ybr1007 shows strong similarities to amino-acid permeases, in particular the high-affinity proline permeases of s. cerevisiae and a. nidulans. the number and position of the predicted membrane-spanning domains suggest a conserved structure for these proteins, with 12 trans-membrane domains. ybr1015 shows strong similarities to serine carboxypeptidases; all three res ...19947954890
premature chromatin condensation upon accumulation of nima.the nima protein kinase of aspergillus nidulans is required for the g2/m transition of the cell cycle. mutants lacking nima arrest without morphological characteristics of mitosis, but they do contain an activated p37nimx kinase (the aspergillus homologue of p34cdc2). to gain a better understanding of nima function we have investigated the effects of expressing various nima constructs in aspergillus, fission yeast and human cells. our experiments have shown that the instability of the nima prote ...19947957060
a cosmid with a hyr marker for fungal library construction and screening.the construction of a double-cos-site cosmid vector, pmocosx, for use in making filamentous fungal genomic dna libraries, is described. the vector has features that allow for selection of clones introduced into fungi by transformation and for efficient chromosome walking experiments. these features include (i) two cos sites allowing for easy construction of libraries without requiring size selection of insert dna; (ii) an xhoi site for insertion of sau3ai or mboi partially digested genomic dna i ...19947959044
virulence studies of aspergillus nidulans mutants requiring lysine or p-aminobenzoic acid in invasive pulmonary identify steps in fungal intermediary metabolism required by aspergillus spp. during invasive pulmonary aspergillosis, we have developed murine models involving aspergillus nidulans as the inoculum. the advantages of using a. nidulans over aspergillus fumigatus or aspergillus flavus, which are the most common agents of clinical disease, are the well-understood genetics of a. nidulans and a large range of mutants of this species which are affected in a variety of metabolic pathways. comparison ...19947960102
a single p34cdc2 protein kinase (encoded by nimxcdc2) is required at g1 and g2 in aspergillus nidulans.we have cloned and sequenced a homolog of cdc2 from aspergillus nidulans that can complement the schizosaccharomyces pombe cdc2-33 mutation. the gene was deleted and is required for continued nuclear dna replication but not for mitochondrial dna replication. three different temperature-sensitive alleles were generated by reverse genetics. all of the mutations generate the nim phenotype of a. nidulans. the new gene was designated nimxcdc2 as it is not allelic to any of the other nim genes (nima t ...19947962194
oxygen requirements of aspergillus species.the growth of 24 aspergillus isolates at low oxygen tensions was assessed. isolates selected included a. fumigatus (10), a. terreus (6), a. niger (6), a. nidulans (1) and a. flavus (1). three different agar media were used--potato dextrose agar (pda), ph 5.6; brain heart infusion (bhi), ph 7.4; and a specially developed medium (hall's) containing resazurin--with oxygen concentrations of 0, 0.025, 0.1, 0.5 and 2.5%. the co2 concentration was 5%. agar plates were inoculated with 2 x 10(7) conidia/ ...19947966201
a fast random cost algorithm for physical mapping.ordering clones from a genomic library into physical maps of whole chromosomes presents a central computational/statistical problem in genetics. here we present a physical mapping algorithm for creating ordered genomic libraries or contig maps by using a random cost approach [berg, a. (1993) nature (london) 361, 708-710]. this random cost algorithm is 5-10 times faster than existing physical mapping algorithms and has optimization performance comparable to existing procedures. the speedup in the ...19947972016
serological survey of infections in waterfowl in the guadalquivir marshes (spain).a serological survey was performed in the guadalquivir marshes (southern spain) in order to determine the presence and diffusion of six infective agents in wild waterfowl. the analysis covered 712 waterfowl from 13 species belonging to five taxa (podicipediformes, ciconiiformes, anseriformes, gruiformes, and charadriiformes). a range of immunological techniques led to detection of antibodies against the six infective agents studied: chlamydia psittaci (13.3%), mycoplasma anatis (3.5%), pasteurel ...19947980291
germinating conidiospores of aspergillus amino acid auxotrophs are hypersensitive to heat shock, oxidative stress and dna damage.germinating conidiospores (conidia) of aspergillus nidulans amino acid-requiring strains are hypersensitive to heat, oxidative stress, uv radiation and chemical mutagens when compared with other strains. they also showed an increased mutation rate. sensitivity to stress conditions has been correlated with an abnormal ras/camp pathway in mutants of s. cerevisiae. we suggest that the ras/camp pathway is defective in germinating conidia of aspergillus amino acid auxotrophs and that this is responsi ...19947982501
bidirectional gene transfer between aspergillus fumigatus and aspergillus nidulans.a genomic dna library was constructed from a pathogenic strain of aspergillus fumigatus using the cosmid vector pcosax. cosmid clones with homologies to the roda, brla, flug, flba or trpc genes from a. nidulans were isolated from the library. each a. fumigatus clone was used to complement a strain of a. nidulans with a mutation in the homologous gene. a spontaneous white spored strain of a. fumigatus was isolated. the mutation was complemented by transforming the strain with a plasmid containing ...19947988865
transcriptional regulation of the trichoderma longibrachiatum egl1 gene.transcription of the trichoderma longibrachiatum egl1 gene is induced in the presence of lactose and beta-methylglucoside and repressed by glucose. a dna fragment containing 722 bp upstream of the atg codon has been sequenced. the gene has two major transcription start points (20 and 24 nucleotides upstream from the atg codon) and several transcription termination points (located in a region around 130 nt downstream of the stop codon). two 6-mer sequences (5'-ctggag-3') separated by 16 bp are pr ...19947988872
characterization of an aspergillus nidulans l-arabitol dehydrogenase mutant.the degradation pathway for l-arabinose, which consists of a sequence of alternating reduction and oxidation reactions prior to ultimate phosphorylation, was studied in aspergillus nidulans wild-type as well as in an l-arabinose non-utilizing mutant. the inability of the mutant to use l-arabinose was caused by the absence of l-arabitol dehydrogenase activity. the effect of the mutation on polyol accumulation patterns was studied upon growth on various carbon sources. the presence of l-arabinose ...19947988903
highly-efficient transformation of the homobasidiomycete schizophyllum commune to phleomycin resistance.regulatory sequences of the glyceraldehyde-3-phosphate-dehydrogenase (gpd) gene from the homobasidiomycete schizophyllum commune were fused to the coding sequence of the ble gene from streptoalloteichus hindustanus, which codes for a phleomycin-binding protein. the resulting construct transformed s. commune to phleomycin resistance at a high frequency (up to 10(4) transformants/microgram dna per 10(7) protoplasts) when regeneration was done in 0.5 m mgso4. a similar construct with regulatory seq ...19948001174
transformation of aspergillus parasiticus using autonomously replicating plasmids from aspergillus nidulans.a genetic transformation system for the aflatoxin-producing fungus aspergillus parasiticus using two autonomously replicating plasmids from a. nidulans (arp1 and pdhg25) is reported. transformation frequencies using the plasmid pdhg25 were from 5 x 10(2) to 2.5 x 10(4) transformants per 10(6) viable protoplasts and microgram dna. the stability of the plasmids in the transformants was also studied. this transformation system offers a new opportunity to clone genes related to aflatoxin production ...19948001767
evolution of cytochrome oxidase, an enzyme older than atmospheric oxygen.cytochrome oxidase is a key enzyme in aerobic metabolism. all the recorded eubacterial (domain bacteria) and archaebacterial (archaea) sequences of subunits 1 and 2 of this protein complex have been used for a comprehensive evolutionary analysis. the phylogenetic trees reveal several processes of gene duplication. some of these are ancient, having occurred in the common ancestor of bacteria and archaea, whereas others have occurred in specific lines of bacteria. we show that eubacterial quinol o ...19948013452
the calmodulin-dependent protein phosphatase catalytic subunit (calcineurin a) is an essential gene in aspergillus nidulans.the gene encoding the homologue of the catalytic subunit of the ca2+/calmodulin-regulated protein phosphatase 2b (calcineurin a) has been isolated from aspergillus nidulans. this gene, cnaa+, is essential in this fungal system. analysis of growth-arrested cells following gene disruption by homologous recombination reveals that they are blocked early in the cell cycle. the cnaa+ gene encodes a 2.5 kb mrna and the deduced protein sequence is highly homologous to the calcineurin a subunit of other ...19948013455
aspergillus nidulans vera is required for production of the mycotoxin sterigmatocystin.aspergillus nidulans produces the carcinogenic mycotoxin sterigmatocystin (st), the next-to-last precursor in the aflatoxin (af) biosynthetic pathway found in the closely related fungi aspergillus flavus and aspergillus parasiticus. we identified and characterized an a. nidulans gene, vera, that is required for converting the af precursor versicolorin a to st. vera is closely related to several polyketide biosynthetic genes involved in polyketide production in streptomyces spp. and exhibits exte ...19948017929
evidence for a h+ nitrate symporter in aspergillus nidulans.nitrate transport in aspergillus nidulans was dependent upon a consistent proton motive force (delta p) across the cell membrane which was maintained in a range of 105 (+/- 6.7) to 131 (+/- 3.4) mv over an external ph span of 5.5 to 7.5. the membrane potential (delta psi) measured by uptake of [3h]-tetra-phenylphosphonium bromide and the transmembrane ph difference (delta ph) measured by the distribution of 3h2o and [14c]- salicylic acid were used to compute the delta p present during transport ...19948022307
mutants of aspergillus nidulans deficient in nuclear migration during hyphal growth and conidiation.anucleate primary sterigmata (aps) mutants of aspergillus nidulans are partially blocked in conidiation (asexual sporulation) due to failure of the organized migration of nuclei into the conidiophore metulae. the mutants also have a slightly reduced hyphal growth rate and irregular distribution of nuclei in vegetative hyphae; the hyphal phenotype appears somewhat more variable than the conidiation defect. the mutants fall into two complementation groups, apsa and apsb, mapping on chromosomes iv ...19948025681
analysis of the regulation of the aspergillus nidulans acud gene, encoding isocitrate lyase, by construction of a hybrid order to confirm functionally that a 208 bp fragment of the 5'-flanking sequence of the acud gene of aspergillus nidulans is the region responsible for acetate inducibility and catabolite repression, a hybrid promoter was constructed by insertion of this fragment into the promoter of the (highly expressed) olic gene of a. nidulans. analysis of expression of the lacz reporter gene fused to the olic/acud promoter showed induction by acetate at much higher levels than wild-type acud expression. ...19948028581
evolutionary conservation of the transcribed spacer sequences of the rdna repeat unit in three species of the genus aspergillus.we have cloned and sequenced the two intervening transcribed spacers in the rdna repeat unit of three aspergillus species--a. nidulans, a. awamori and a. wentii. the a. wentii and a. awamori spacers are almost identical and share a high degree of homology with the a. nidulans spacers. all spacers have a high g-c content (66%-76%) and the potential of forming complex secondary structures, which may indicate that they play a role in the maturation of pre-rrna molecules.19948030378
developmental decisions in aspergillus nidulans are modulated by ras better understand how ras controls development of multicellular organisms, we have chosen aspergillus nidulans as a model system. when grown on solid medium, this fungus follows a well-defined program of development, sequentially giving rise to several cell types which produce three distinct structures: vegetative hyphae, aerial hyphae, and the conidiophore structure. here we describe a ras homolog found in this fungus (aras) and demonstrate that it is an essential gene that regulates the ord ...19948035812
efficient independent activity of a monomeric, monofunctional dehydroquinate synthase derived from the n-terminus of the pentafunctional arom protein of aspergillus nidulans.the dehydroquinate synthase (dhq synthase) functional domain from the pentafunctional arom protein of aspergillus nidulans has previously been overproduced in escherichia coli [van den hombergh, moore, charles and hawkins (1992) biochem j. 284, 861-867]. we now report the purification of this domain to homogeneity and subsequent characterization. the monofunctional dhq synthase was found to retain efficient catalytic activity when compared with the intact pentafunctional arom protein of neurospo ...19948037684
nitrate reductase of the ascomycetous fungus, leptosphaeria maculans: gene sequence and chromosomal location.the nitrate reductase (niad) gene was isolated from the phytopathogenic loculoascomycete leptosphaeria maculans by screening a genomic dna library with the aspergillus nidulans niad gene. the l. maculans niad gene is the first protein-encoding gene characterised from this fungus. it encodes a predicted protein of 893 amino acids and contains four putative introns at positions in the gene equivalent to those of four of the six introns in the a. nidulans niad gene. mutants defective in niad and mo ...19948041355
synthesis of sterigmatocystin on a chemically defined medium by species of aspergillus and chaetomium.sterigmatocystin (st) is a secondary metabolite and a principal mycotoxin known to be produced by over 30 species of filamentous fungi. it is also one of the late intermediates in aflatoxin biosynthesis. we have tested the ability of 7 species of aspergillus, including 4 strains of a. versicolor, one species of bipolaris, and two species of chaetomium, to produce st on a sucrose-salts-phenylalanine defined medium as well as on three complex substrates. highest st production in our survey was by ...19948047108
enhancers of conidiation mutants in aspergillus nidulans.mutants at a number of loci, designated sthenyo, have been isolated as enhancers of the oligoconidial mutations at the meda locus. two loci have been mapped: stha on linkage group i, and sthb on linkage group v. two probable alleles have been identified at each locus but two further mutants were unlinked to either stha or sthb. neither stha nor sthb mutants have conspicuous effects on morphology on their own, nor could the stha1 sthb2 double mutant be distinguished from wild type. mutants at bot ...19948056325
synechocystis sp. pcc6803 fusb gene, located outside of the str operon, encodes a polypeptide related to protein synthesis factor ef-g.synechocystis sp. pcc6803, a cyanobacterium, possesses an unusual gene (fusb) which encodes a protein with strong homology to protein synthesis elongation factor g (ef-g), although it is not linked to the classical str operon. the fusb gene is redundant, since a synechocystis gene similar to str operon-encoded fusa genes of other bacteria is also present (based on pcr and hybridization results). there is no evidence for the presence of a fusb homologue in other bacteria. the synechocystis fusb g ...19948061323
regulation of the xylanase-encoding xlna gene of aspergillus tubigensis.a gene encoding an endo-1,4-beta-xylanase from aspergillus tubigensis was cloned by oligonucleotide screening using oligonucleotides derived from amino acid sequence data obtained from the purified protein. the isolated gene was functional as it could be expressed in the very closely related fungus aspergillus niger. the xylanase encoded by this gene is synthesized as a protein of 211 amino acids. after cleavage of the presumed prepropeptide this results in a mature protein of 184 amino acids wi ...19948065265
hyphal tip extension in aspergillus nidulans requires the mana gene, which encodes phosphomannose isomerase.a strain of aspergillus nidulans carrying a temperature-sensitive mutation in the mana gene produces cell walls depleted of d-mannose and forms hyphal tip balloons at the restrictive temperature (b.p. valentine and b.w. bainbridge, j. gen. microbiol. 109:155-168, 1978). we have isolated and characterized the mana gene and physically located it between 3.5 and 5.5 kb centromere distal of the ribob locus on chromosome viii. the mana gene contains four introns and encodes a 50.6-kda protein which h ...19948065336
the calmodulin-dependent protein phosphatase catalytic subunit (calcineurin a) is an essential gene in aspergillus nidulans.the gene encoding the homologue of the catalytic subunit of the ca2+/calmodulin-regulated protein phosphatase 2b (calcineurin a) has been isolated from aspergillus nidulans. this gene, cnaa+, is essential in this fungal system. analysis of growth-arrested cells following gene disruption by homologous recombination reveals that they are blocked early in the cell cycle. the cnaa+ gene encodes a 2.5 kb mrna and the deduced protein sequence is highly homologous to the calcineurin a subunit of other ...19948070419
the aspergillus nidulans crea protein mediates glucose repression of the ethanol regulon at various levels through competition with the alcr-specific transactivator.carbon catabolite repression in aspergillus nidulans is mediated by a negative-acting protein coded by the crea gene. we have investigated how crea controls the expression of the ethanol regulon genes. crea is a major component of the control of this regulon. its presence in the cell results in a permanent, albeit partial, repression of the alc genes under all physiological growth conditions, even when the fungus is grown on carbon sources considered to be non-repressing. a crucial step in the c ...19948076597
evolution of transcription-regulating proteins by enzyme recruitment: molecular models for nitrogen metabolite repression and ethanol utilisation in eukaryotes.studies on the quinic acid utilisation gene (qut) cluster in aspergillus nidulans showed that the genes encoding transcriptional activator and repressor proteins evolved by co-opting duplicated copies of genes encoding metabolic enzymes. in order to test the hypothesis that this was a general route for the genesis of regulatory proteins, the origins of the major control protein mediating nitrogen metabolite repression (an example of inter-pathway regulation) and ethanol utilisation (an example o ...19948076813
cloning and characterization of the pda6-1 gene encoding a fungal cytochrome p-450 which detoxifies the phytoalexin pisatin from garden pea.the ability to detoxify pisatin, a phytoalexin produced by garden pea (pisum sativum), is controlled by a family of pda (pisatin demethylating ability) genes in the phytopathogenic fungus nectria haematococa, mp (mating population) vi. six known pda genes each encode characteristic levels of inducible enzyme activity and are associated with different degrees of virulence on pea. to elucidate the phenotypic differences associated with these genes, we have cloned and characterized the pda6-1 gene ...19948076822
the penicillium chrysogenum and aspergillus nidulans weta developmental regulatory genes are functionally equivalent.aspergillus nidulans and penicillium chrysogenum are related fungi that reproduce asexually by forming multicellular conidiophores and uninucleate conidia. in a. nidulans, spore maturation is controlled by the weta (aweta) regulatory gene. we cloned a homologous gene (pweta) from p. chrysogenum to determine if spore maturation is regulated by a similar mechanism in this species. the pweta and aweta genes are similar in structure and functional organization. the inferred polypeptides share 77% ov ...19948078481
a new selection method for isolating mutants defective in acetate utilisation in aspergillus nidulans.propionate medium is normally toxic for the growth of aspergillus nidulans. spontaneous mutations relieving the toxicity to propionate, which arose on propionate medium, have been shown to be mutations in acetate metabolism. one acu- mutant is allelic with acua (the structural gene for acetyl-coa synthetase), another with acub (the regulatory gene involved in the induction of enzymes concerned with acetate metabolism, including acetyl-coa synthetase), and a third mutant, acuo, represents a new a ...19948082165
transformation of trichoderma reesei based on hygromycin b resistance using homologous expression signals.trichoderma reesei was transformed to hygromycin b resistance using a novel vector, which contains the e. coli hygromycin b phosphotransferase gene (hph) fused between promoter and terminator elements of the homologous trichoderma pki1 (coding for pyruvate kinase) and cbh2 (coding for cellobiohydrolase ii) genes, respectively. transformation frequencies of over 1,800--2,500 transformants/micrograms dna were obtained, which is a 15--20-fold increase over that with pan7-1, which contains hph betwe ...19948082210
biolistic transformation of conidia of botryotinia fuckeliana.botryotinia fuckeliana, the causal agent of grey mould, was biolistically transformed to hygromycin b resistance using a plasmid (poht) containing a bacterial hygromycin phosphotransferase gene fused to regulatory sequences from aspergillus nidulans. multiple copies of the plasmid, precipitated onto tungsten particles, were delivered into the conidia by a helium-driven gene gun. southern analysis showed that the plasmid was integrated into the fungal genome at one single locus. after five subseq ...19948087880
toxin-deficient mutants from a toxin-sensitive transformant of cochliobolus heterostrophus.tox1 is the only genetic element identified which controls production of t-toxin, a linear polyketide involved in the virulence of cochliobolus heterostrophus to its host plant, corn. previous attempts to induce toxin-deficient (tox-) mutants, using conventional mutagenesis and screening procedures, have been unsuccessful. as a strategy to enrich for tox- mutants, we constructed a tox1+ strain that carried the corn t-urf13 gene (which confers t-toxin sensitivity) fused to a fungal mitochondrial ...19948088521
isolation and characterization of two chitin synthase genes from aspergillus nidulans.two chitin synthase genes, designated chsa and chsb, were isolated from aspergillus nidulans with the saccharomyces cerevisiae chs2 gene as the hybridization probe. nucleotide sequencing showed that chsa and chsb encoded polypeptides consisting of 1013 and 916 amino acid residues, respectively; the hydropathy profiles of the enzymes were similar to those of other fungal chitin synthases. northern analysis indicated that both genes were transcribed, suggesting that cellular chitin in a. nidulans ...19947765508
genetic modification of an echinocandin b-producing strain of aspergillus nidulans to produce mutants blocked in sterigmatocystin biosynthesis.the production of echinocandin b (ecb), a lipopolypeptide used for chemical manufacture of the anti-candida agent cilofungin, was accomplished by fermentation using a strain of aspergillus nidulans. in addition to ecb, this fermentation also produces a significant amount of sterigmatocystin (st), a potent carcinogen structurally related to the aflatoxins. mutants blocked in the st biosynthetic pathway were created by genetic modification of the polyploid production strain c747. the following ste ...19947765669
isolation of a chitin synthase gene (chsc) of aspergillus nidulans.we isolated a class i chitin synthase gene (chsc) from aspergillus nidulans. expression of this gene was confirmed by northern analysis and by sequencing of the pcr-amplified dna fragments from cdna. chsc disruptants showed no difference of morphology in the asexual cycle and no difference of growth rate compared to a wild-type strain.19947765719
molecular cloning and sequence analysis of the cellobiohydrolase i gene from trichoderma koningii g-39.the cellobiohydrolase i gene, cbh1, has been cloned from an enhanced cellulase-producing strain, trichoderma koningii g-39. sequence comparisons show that t. koningii cbh1 is identical to that of t. reesei with the exception of 6 bp--two causing silent substitutions in the coding region, three differing in one of the introns, and one in 5'-noncoding region. thus, it should encode an identical cbhi to that of t. reesei despite the differences in morphological characters of the two species. analys ...19947764306
genetic requirements for initiating asexual development in aspergillus nidulans.conidiation in the filamentous ascomycete aspergillus nidulans requires activation of brla, a well-characterized transcriptional regulator of genes that are induced specifically during asexual development. we have isolated and characterized developmental mutations in six loci, designated flug, flba, flbb, flbc, flbd, and flbe, that result in defective development and reduced brla expression. these mutants grow indeterminately to produce masses of aerial hyphae resulting in the formation of cotto ...19947750148
how many 5s rrna genes and pseudogenes are there in aspergillus nidulans?we have estimated the number of 5s rrna genes in aspergillus nidulans using two-dimensional agarose gel electrophoresis and hybridization to appropriate probes, representing the 5'-halves, the 3'-halves of the 5s rrna sequence and a sequence found at the 3'-end of all known a. nidulans pseudogenes (block c). we have found 23 5s rrna genes, 15 pseudogenes consisting of the 5'-half of the 5s rrna sequence (of which 3 are flanked by block c) and 12 copies of block c which do not seem to be in the v ...19947732763
purification of arginase from aspergillus nidulans.arginase (ec of aspergillus nidulans, the enzyme which enables the fungus to use arginine as the sole nitrogen source was purified to homogeneity. molecular mass of the purified arginase subunit is 40 kda and is similar to that reported for the neurospora crassa (38.3 kda) and saccharomyces cerevisiae (39 kda) enzymes. the native molecular mass of arginase is 125 kda. the subunit/native molecular mass ratio suggests a trimeric form of the protein. the arginase protein was cleaved and pa ...19947732765
a case of chronic necrotizing pulmonary aspergillosis due to aspergillus nidulans.a 55-year old man without immunosuppression clinically showed a coin lesion in the right lower lung on the chest radiographs. aspergillus nidulans was isolated and identified in both trans-bronchial lung biopsy specimen and resected tissue. the specimens revealed characteristics of chronic necrotizing pulmonary aspergillosis pathologically. very few reports on cases of pulmonary aspergillosis due to a. nidulans exist, and we were not able to find any reports of similar cases. this case may be th ...19947777037
nitrogen regulation in fungi.nitrogen regulation has been extensively studied in fungi revealing a complex array of interacting regulatory genes. the general characterisation of the systems in aspergillus nidulans and neurospora crassa shall be briefly described, but much of this paper will concentrate specifically on the recent molecular characterisation of area, the principle regulatory gene from a. nidulans which mediates nitrogen metabolite repression. three areas shall be explored in detail, firstly the dna binding dom ...19947847882
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