PMID(sorted descending)
nonribosomal peptide synthesis in schizosaccharomyces pombe and the architectures of ferrichrome-type siderophore synthetases in fungi.a nonribosomal peptide synthetase (nrps) in schizosaccharomyces pombe, which possesses an unusual structure incorporating three adenylation domains, six thiolation domains and six condensation domains, has been shown to produce the cyclohexapeptide siderophore ferrichrome. one of the adenylation domains is truncated and contains a distorted key motif. substrate-binding specificities of the remaining two domains were assigned by molecular modelling to glycine and to n-acetyl-n-hydroxy-l-ornithine ...200616502473
genomics of aspergillus fumigatus.aspergillus fumigatus is a filamentous fungal saprophyte that is ubiquitous in the environment. it is also a human pathogen and induces allergenic response, negatively impacting health care and associated costs significantly around the world. much of the basic biology of this organism is only poorly understood, but the recent completion and publication of its genome sequence provides an excellent tool for researchers to gain insight into these processes. in this review we will summarize some of ...200516499415
agrobacterium tumefaciens-mediated transformation of mucor circinelloides.the agrobacterium tumefaciens-mediated transformation of the zygomycetous fungus mucor circinelloides is described. a method was also developed for the hygromycin b-based selection of mucor transformants. transformation with the hygromycin b phosphotransferase gene of escherichia coli controlled by the heterologous aspergillus nidulans trpc promoter resulted in hygromycin b-resistant clones. the presence of the hygromycin resistance gene in the genome of the transformants was verified by polymer ...200516475501
mapping the primary structure of copper/topaquinone-containing methylamine oxidase from aspergillus niger.the amino acid sequence of methylamine oxidase (meao) from the fungus aspergillus niger was analyzed using mass spectrometry (ms). first, meao was characterized by an accurate molar mass of 72.4 kda of the monomer measured using maldi-tof-ms and by a pi value of 5.8 determined by isoelectric focusing. maldi-tof-ms revealed a clear peptide mass fingerprint after tryptic digestion, which did not provide any relevant hit when searched against a nonredundant protein database and was different from t ...200516475499
impact of fungal drug transporters on fungicide sensitivity, multidrug resistance and virulence.drug transporters are membrane proteins that provide protection for organisms against natural toxic products and fungicides. in plant pathogens, drug transporters function in baseline sensitivity to fungicides, multidrug resistance (mdr) and virulence on host plants. this paper describes drug transporters of the filamentous fungi aspergillus nidulans (eidam) winter, botrytis cinerea pers and mycosphaerella graminicola (fückel) schroter that function in fungicide sensitivity and resistance. the f ...200616475240
purification and properties of an extracellular endo-1,4-beta-xylanase from penicillium citrinum and characterization of the encoding extracellular endo-1,4-beta-xylanase was purified from the culture filtrate of a filamentous fungus penicillium citrinum ferm p-15944 grown on birch-wood xylan. the purified enzyme showed a single band on sds-page with an apparent m(r) of 20,000 and had an isoelectric point below 3.5. xylanase activity was optimal at ph 5.0 and 55 degrees c. the genomic dna and cdnas encoding this protein were cloned and sequenced. southern blot analysis indicated that the xylanase gene (xyna) was present as ...200516473771
aspergillus nidulans class v and vi chitin synthases csma and csmb, each with a myosin motor-like domain, perform compensatory functions that are essential for hyphal tip growth.the polarized synthesis of cell wall components such as chitin is essential for the hyphal tip growth of filamentous fungi. the actin cytoskeleton is known to play important roles in the determination of hyphal polarity in aspergillus nidulans. previously, we suggested that csma, a chitin synthase with a myosin motor-like domain (mmd), was involved in polarized chitin synthesis in a manner dependent on the interaction between the mmd and the actin cytoskeleton. the genome database indicates that ...200616468983
the phosducin-like protein phna is required for gbetagamma-mediated signaling for vegetative growth, developmental control, and toxin biosynthesis in aspergillus nidulans.phosducin or phosducin-like protein (phlp) is a positive regulator of gbetagamma activity. the gbeta (sfad) and ggamma (gpga) subunits function in vegetative growth and developmental control in the model filamentous fungus aspergillus nidulans. to better understand the nature of gbetagamma-mediated signaling, phna, encoding an a. nidulans phlp, has been studied. deletion of phna resulted in phenotypes almost identical to those caused by deletion of sfad, i.e., reduced biomass, asexual sporulatio ...200616467480
differential expression of aspergillus nidulans ammonium permease genes is regulated by gata transcription factor area.the movement of ammonium across biological membranes is mediated in both prokaryotes and eukaryotes by ammonium transport proteins (amt/mep) that constitute a family of related sequences. we have previously identified two ammonium permeases in aspergillus nidulans, encoded by the meaa and mepa genes. here we show that meaa is expressed in the presence of ammonium, consistent with the function of meaa as the main ammonium transporter required for optimal growth on ammonium as a nitrogen source. i ...200616467464
clip-170 homologue and nude play overlapping roles in nudf localization in aspergillus nidulans.proteins in the cytoplasmic dynein pathway accumulate at the microtubule plus end, giving the appearance of comets when observed in live cells. the targeting mechanism for nudf (lis1/pac1) of aspergillus nidulans, a key component of the dynein pathway, has not been clear. previous studies have demonstrated physical interactions of nudf/lis1/pac1 with both nude/nudel/ndl1 and clip-170/bik1. here, we have identified the a. nidulans clip-170 homologue, clipa. the clipa deletion did not cause an obv ...200616467375
intrinsic in vitro susceptibility of primary clinical isolates of aspergillus fumigatus, aspergillus terreus, aspergillus nidulans, candida albicans and candida lusitaniae against amphotericin b.a total of 60 clinical fungal isolates from patients without prior amphotericin b treatment and three control strains were evaluated for their intrinsic susceptibility to amphotericin b (amb) using microdilution, etest and disc diffusion assays, on three media each, roswell park memorial institute (rpmi) 1640, antibiotic medium 3 (am3) and high resolution medium. the fungal strains included isolates of aspergillus fumigatus (n = 10), aspergillus terreus (n = 12), aspergillus nidulans (n = 9), ca ...200616466441
the aspergillus nidulans xprg (phog) gene encodes a putative transcriptional activator involved in the response to nutrient limitation.the aspergillus nidulans xprg gene is involved in the regulation of extracellular proteases. a plasmid which complemented the xprg2 mutation was shown to carry the phog gene, reported to encode an acid phosphatase. two phogdelta mutants were constructed and were identical in phenotype to an xprg2 mutant. null mutants were unable to use protein as a carbon or nitrogen source, have lost a repressible acid phosphatase and have pale conidial color. xprg shows similarity to the ndt80 transcriptional ...200616464624
a novel-type substrate-selectivity filter and er-exit determinants in the uapa purine transporter.we present a functional analysis of the last alpha-helical transmembrane segment (tms12) of uapa, a uric acid-xanthine/h+ symporter in aspergillus nidulans and member of the nucleobase-ascorbate transporter (nat) family. first, we performed a systematic mutational analysis of residue f528, located in the middle of tms12, which was known to be critical for uapa specificity. substitution of f528 with non-aromatic amino acid residues (ala, thr, ser, gln, asn) did not affect significantly the kineti ...200616464466
the aflatoxin biosynthesis cluster gene, aflx, encodes an oxidoreductase involved in conversion of versicolorin a to demethylsterigmatocystin.biosynthesis of the toxic and carcinogenic aflatoxins by the fungus aspergillus flavus is a complicated process involving more that 27 enzymes and regulatory factors encoded by a clustered group of genes. previous studies found that three enzymes, encoded by vera, ver-1, and afly, are required for conversion of versicolorin a (va), to demethylsterigmatocystin. we now show that a fourth enzyme, encoded by the previously uncharacterized gene, aflx (ordb), is also required for this conversion. a ho ...200616461654
glass-fiber disks provide suitable medium to study polyol production and gene expression in eurotium rubrum.eurotium species often dominate the fungal population in stored grain and are responsible for spoilage. in this study we tested the usefulness of glass fiber disks to aid the analysis of growth, polyol content and gene expression in e. rubrum in response to various water activities. growth measurements based on ergosterol content and conidial production indicated that e. rubrum grew as well at 0.86 aw as 0.98 aw. the rate of growth was considerably reduced at 0.83 aw and 0.78 aw. in contrast, un ...200516457343
evaluation of agrobacterium-mediated transformation of agaricus bisporus using a range of promoters linked to hygromycin resistance.there is interest in establishing genetic modification technologies for the cultivated mushroom agaricus bisporus, both for improved crop characteristics and for molecular pharming. for these methods to be successful, it is necessary to establish a set of transformation systems that include robust and reliable vectors for gene manipulation. in this article, we report the evaluation of a series of promoters for driving expression of the escherichia coli hph gene encoding hygromycin phosphotransfe ...200616444014
genomic mining for aspergillus natural products.the genus aspergillus is renowned for its ability to produce a myriad of bioactive secondary metabolites. although the propensity of biosynthetic genes to form contiguous clusters greatly facilitates assignment of putative secondary metabolite genes in the completed aspergillus genomes, such analysis cannot predict gene expression and, ultimately, product formation. to circumvent this deficiency, we have examined aspergillus nidulans microarrays for expressed secondary metabolite gene clusters b ...200616426969
a global view of metabolites.fungi are rich sources of medically useful, as well as toxic, secondary metabolites. in this issue of chemistry & biology, bok et al. show that, in aspergillus nidulans, microarray analysis and manipulation of a global regulator can identify novel metabolite genes.200616426964
oxylipins act as determinants of natural product biosynthesis and seed colonization in aspergillus nidulans.secreted, hormone-like lipogenic molecules, called oxylipins, mediate the balance of asexual to sexual spore ratio in aspergillus nidulans. oxylipin production in this fungus is dependent on developmental regulation of three conserved fatty acid oxygenases, ppoa, ppob and ppoc. here, we show that in addition to altering spore ratios, loss of ppo genes affect natural product biosynthesis and seed colonization. deltappoa;deltappoc and deltappoa;deltappob;deltappoc mutants were unable to produce th ...200616420358
tmpa, a member of a novel family of putative membrane flavoproteins, regulates asexual development in aspergillus nidulans.asexual reproduction (conidiation) in aspergillus nidulans is induced by environmental signals like exposure to air or nutrient starvation, and depends on brla gene activation. the study of 'fluffy' mutants showing delayed asexual development and reduced brla expression has defined the flug pathway, involved in regulation of this differentiation process. genetic characterization of a 'fluffy' mutant identified tmpa as a new gene involved in regulation of conidiation. tmpa defines a new family of ...200616420356
farnesol-induced apoptosis in aspergillus nidulans reveals a possible mechanism for antagonistic interactions between fungi.the dimorphic fungus candida albicans secretes farnesol, which acts as a quorum-sensing molecule and prevents the yeast to mycelium conversion. in this study we examined the effect of farnesol in the filamentous fungus aspergillus nidulans. we show that externally added farnesol has no effect on hyphal morphogenesis; instead, it triggers morphological features characteristic of apoptosis. additional experiments suggest that mitochondria and reactive oxygen species (ros) participate in farnesol-i ...200616420349
identification of the mste gene encoding a glucose-inducible, low affinity glucose transporter in aspergillus nidulans.the mste gene encoding a low affinity glucose transporter active during the germination of aspergillus nidulans conidia on glucose medium has been identified. mste expression also occurs in hyphae, is induced in the presence of other repressing carbon sources besides glucose, and is dependent on the function of the transcriptional repressor crea. the expression of mste and its subcellular distribution have been studied using a mste-sgfp fusion protein. concordant with data on mste expression, ms ...200616418173
regulation of hyphal morphogenesis and the dna damage response by the aspergillus nidulans atm homolog atma.ataxia telangiectasia (a-t) is an inherited disorder characterized by progressive loss of motor function and susceptibility to cancer. the most prominent clinical feature observed in a-t patients is the degeneration of purkinje motor neurons. numerous studies have emphasized the role of the affected gene product, atm, in the regulation of the dna damage response. however, in purkinje cells, the bulk of atm localizes to the cytoplasm and may play a role in vesicle trafficking. the nature of this ...200616415361
screening of growth- or development-related genes by using genomic library with inducible promoter in aspergillus nidulans.using the genomic library constructed at the downstream of the niia promoter, which induces the over-expression of an inserted dna fragment, we have attempted to screen the genes affecting growth or development by over-expression. the wild-type strain was transformed using the ama-niia(p) library and cultured on 1.2 m sorbitol media, in which asexual sporulation is induced, but sexual development is repressed. over 100,000 strains transformed to pyrg(+) were analyzed with regard to any changes i ...200516410769
genomics reveals traces of fungal phenylpropanoid-flavonoid metabolic pathway in the f ilamentous fungus aspergillus oryzae.fungal secondary metabolites constitute a wide variety of compounds which either play a vital role in agricultural, pharmaceutical and industrial contexts, or have devastating effects on agriculture, animal and human affairs by virtue of their toxigenicity. owing to their beneficial and deleterious characteristics, these complex compounds and the genes responsible for their synthesis have been the subjects of extensive investigation by microbiologists and pharmacologists. a majority of the funga ...200516410762
the presence of gc-ag introns in neurospora crassa and other euascomycetes determined from analyses of complete genomes: implications for automated gene prediction.a combination of experimental and computational approaches was employed to identify introns with noncanonical gc-ag splice sites (gc-ag introns) within euascomycete genomes. evaluation of 2335 cdna-confirmed introns from neurospora crassa revealed 27 such introns (1.2%). a similar frequency (1.0%) of gc-ag introns was identified in fusarium graminearum, in which 3 of 292 cdna-confirmed introns contained gc-ag splice sites. computational analyses of the n. crassa genome using a gc-ag intron conse ...200616406724
distinct ceramide synthases regulate polarized growth in the filamentous fungus aspergillus filamentous fungi, the stabilization of a polarity axis is likely to be a pivotal event underlying the emergence of a germ tube from a germinating spore. recent results implicate the polarisome in this process and also suggest that it requires localized membrane organization. here, we employ a chemical genetic approach to demonstrate that ceramide synthesis is necessary for the formation of a stable polarity axis in the model fungus aspergillus nidulans. we demonstrate that a novel compound ( ...200616394102
the gata factor area regulates localization and in vivo binding site occupancy of the nitrate activator nira.the gata factor area is a wide-domain regulator in aspergillus nidulans with transcriptional activation and chromatin remodelling functions. area interacts with the nitrate-specific zn(2)-c(6) cluster protein nira and both proteins cooperate to synergistically activate nitrate-responsive genes. we have previously established that nira in vivo dna binding site occupancy is area dependent and in this report we provide a mechanistic explanation for our previous findings. we now show that area regul ...200616390440
a versatile and efficient gene-targeting system for aspergillus nidulans.aspergillus nidulans is an important experimental organism, and it is a model organism for the genus aspergillus that includes serious pathogens as well as commercially important organisms. gene targeting by homologous recombination during transformation is possible in a. nidulans, but the frequency of correct gene targeting is variable and often low. we have identified the a. nidulans homolog (nkua) of the human ku70 gene that is essential for nonhomologous end joining of dna in double-strand b ...200616387870
flug-dependent asexual development in aspergillus nidulans occurs via derepression.the asexual spore is one of the most crucial factors contributing to the fecundity and fitness of filamentous fungi. although the developmental activator flug was shown to be necessary for activation of asexual sporulation (conidiation) and production of the carcinogenic mycotoxin sterigmatocystin (st) in the model filamentous fungus aspergillus nidulans, the molecular mechanisms underlying the developmental switch have remained elusive. in this study, we report that the flug-mediated conidiatio ...200616387865
visualization of the endocytic pathway in the filamentous fungus aspergillus oryzae using an egfp-fused plasma membrane protein.endocytosis is an important process for cellular activities. however, in filamentous fungi, the existence of endocytosis has been so far elusive. in this study, we used aouapc-egfp, the fusion protein of a putative uric acid-xanthine permease with enhanced green fluorescent protein (egfp) in aspergillus oryzae, to examine whether the endocytic process occurs or not. upon the addition of ammonium into the medium the fusion protein was internalized from the plasma membrane. the internalization of ...200616380079
development of a modified positive selection medium that allows to isolate aspergillus oryzae strains cured of the integrated niad-based plasmid.the nitrate reductase gene (niad) is the most frequently utilized as a selectable marker for homologous integration at the niad locus of aspergillus oryzae. in this study we developed a method for curing of the niad-based plasmid integrated on the a. oryzae genome. positive selection using a modified chlorate medium containing leucine as a nitrogen source enabled efficient isolation of the strains deficient in nitrate assimilation from the niad(+) transformant. pcr analysis of the strains confir ...200516377911
analysis of the aspergillus nidulans thaumatin-like ceta gene and evidence for transcriptional repression of pyr4 expression in the ceta-disrupted strain.the asexual spore or conidium plays a critical role in the life cycle of many filamentous fungi. however, the process of conidial germination remains surprisingly obscure. to better understand this process at the molecular level we characterized the aspergillus nidulans ceta gene which is uniquely transcribed in conidiating cultures and whose transcript is significantly enriched in mature conidia. ceta is a member of a novel family of fungal genes of unknown function with homology to plant thaum ...200616376592
genome sequencing and analysis of aspergillus oryzae.the genome of aspergillus oryzae, a fungus important for the production of traditional fermented foods and beverages in japan, has been sequenced. the ability to secrete large amounts of proteins and the development of a transformation system have facilitated the use of a. oryzae in modern biotechnology. although both a. oryzae and aspergillus flavus belong to the section flavi of the subgenus circumdati of aspergillus, a. oryzae, unlike a. flavus, does not produce aflatoxin, and its long histor ...200516372010
sequencing of aspergillus nidulans and comparative analysis with a. fumigatus and a. oryzae.the aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. here we report the genome sequence of the model organism aspergillus nidulans, and a comparative study with aspergillus fumigatus, a serious human pathogen, and aspergillus oryzae, used in the production of sake, miso and soy sauce. our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. it also led to an experimentally va ...200516372000
genetic transformation of ascochyta rabiei using agrobacterium-mediated order to study pathogenic mechanisms of the plant pathogen ascochyta rabiei, conditions for efficient transformation using agrobacterium-mediated transformation were investigated. hygromycin b resistance (hph) was superior to geneticin resistance (nptii) for selecting transformants, and the hph gene was more efficiently expressed by the aspergillus nidulans trpc promoter than by the cauliflower mosaic virus 35s promoter camv35s. co-cultivation on solid media for 72 h was optimal for generatin ...200616369840
comparison of gene expression signatures of diamide, h2o2 and menadione exposed aspergillus nidulans cultures--linking genome-wide transcriptional changes to cellular addition to their cytotoxic nature, reactive oxygen species (ros) are also signal molecules in diverse cellular processes in eukaryotic organisms. linking genome-wide transcriptional changes to cellular physiology in oxidative stress-exposed aspergillus nidulans cultures provides the opportunity to estimate the sizes of peroxide (o2(2-)), superoxide (o2*-) and glutathione/glutathione disulphide (gsh/gssg) redox imbalance responses.200516368011
a mapk gene from dead sea fungus confers stress tolerance to lithium salt and freezing-thawing: prospects for saline agriculture.the dead sea is one of the most saline lakes on earth ( approximately 340 g/liter salinity) and is approximately 10 times saltier than the oceans. eurotium herbariorum, a common fungal species, was isolated from its water. ehhog gene, encoding a mitogen-activated protein kinase (mapk) that plays an essential role in the osmoregulatory pathway in yeast and many other eukaryotes, was isolated from e. herbariorum. the deduced amino acid sequences of ehhog indicated high similarity with homologous g ...200516365289
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
genetic transformation of an argb mutant of aspergillus argb mutant of aspergillus oryzae nrrl 492 has been genetically transformed with the aspergillus nidulans argb gene. protoplasts were generated with a combination of novozyme 234 and beta-glucuronidase and regenerated on sucrose-stabilized minimal medium without arginine as described for a. nidulans. a frequency of 5 to 10 transformants per mug of dna was obtained; however, most transformants appeared abortive. the a. nidulans argb gene and vector sequences appeared to be integrated into the ...198816347669
c21orf5, a new member of dopey family involved in morphogenesis, could participate in neurological alterations and mental retardation in down syndrome.availability of the human genome sequence promises important progress in the understanding of human pathologies, particularly for multifactorial diseases. among these, down syndrome (ds) is the most frequent genetic cause of mental retardation. a critical region of chromosome 21, the down syndrome chromosomal region-1 (dcr-1), is responsible for many features of the ds phenotype including mental retardation. we studied dcr-1 c21orf5 as a new candidate gene for ds considering its restricted expre ...200516303751
deletions of endocytic components vps28 and vps32 affect growth at alkaline ph and virulence through both rim101-dependent and rim101-independent pathways in candida albicans.ambient ph signaling involves a cascade of conserved rim or pal products in ascomycetous yeasts or filamentous fungi, respectively. recent evidences in the fungi aspergillus nidulans, saccharomyces cerevisiae, yarrowia lipolytica, and candida albicans suggested that components of endosomal sorting complexes required for transport (escrt) involved in endocytic trafficking were needed for signal transduction along the rim pathway. in this study, we confirm these findings with c. albicans and show ...200516299290
g protein-coupled receptor gpr4 senses amino acids and activates the camp-pka pathway in cryptococcus neoformans.the galpha protein gpa1 governs the camp-pka signaling pathway and plays a central role in virulence and differentiation in the human fungal pathogen cryptococcus neoformans, but the signals and receptors that trigger this pathway were unknown. we identified seven putative proteins that share identity with known g protein-coupled receptors (gpcrs). one protein, gpr4, shares limited sequence identity with the dictyostelium discoideum camp receptor car1 and the aspergillus nidulans gpcr protein gp ...200616291861
tracing the endocytic pathway of aspergillus nidulans with fm4-64.simple procedures using fm4-64 to follow membrane internalization and transport to the vacuolar system and endomembranes in aspergillus nidulans are described. fm4-64 internalization is energy, temperature and f-actin dependent, strongly suggesting that it occurs by endocytosis. the dye sequentially labels: (i) cortical punctuate organelles whose motility resembles that of yeast actin patches; (ii) approximately 0.7 microm circular, hollow structures representing mature endosome/vacuole; and (ii ...200516291501
efficient pcr-based gene targeting with a recyclable marker for aspergillus nidulans.the rapid accumulation of genomic sequences from a large number of eukaryotes, including numerous filamentous fungi, has created a tremendous scientific potential, which can only be realized if precise site-directed genome modifications, like gene deletions, promoter replacements, in-frame gfp fusions and specific point mutations can be made rapidly and reliably. the development of gene-targeting techniques in filamentous fungi and other higher eukaryotes has been hampered because foreign dna is ...200616289954
surface ultrastructure and elasticity in growing tips and mature regions of aspergillus hyphae describe wall maturation.this study reports the first direct, high-resolution physical and structural evidence of wall changes during hyphal tip growth, visualized by atomic force microscopy (afm) in aspergillus nidulans. images from afm and cryo-scanning electron microscopy provided comparable information, but afm was also able to image and physically probe living cells. afm images showed changes in the surface ultrastructure of a. nidulans hyphae, from newly deposited walls at hyphal tips to fully mature walls, as wel ...200516272389
protein o-mannosyltransferase a of aspergillus awamori is involved in o-mannosylation of glucoamylase i.industrially important extracellular enzymes from filamentous fungi are often o-mannosylated. the structure and function of the pmta (aapmta) gene encoding the protein o-d-mannosyltransferase of aspergillus awamori were characterized. the aapmta disruptant, designated aapmta, was constructed by homologous recombination. the strain aapmta exhibited fragile cell morphology with respect to hyphal extension, as well as swollen hyphae formation and conidia formation in potato dextrose medium. moreove ...200516272387
the aspergillus nidulans phytochrome fpha represses sexual development in red light.phytochrome photoreceptors sense red and far-red light through photointerconversion between two stable conformations, a process mediated by a linear tetrapyrrole chromophore. originally, phytochromes were thought to be confined to photosynthetic organisms including cyanobacteria, but they have been recently discovered in heterotrophic bacteria and fungi, where little is known about their functions. it was shown previously in the ascomycetous fungus aspergillus nidulans that asexual sporulation i ...200516243030
photosensing fungi: phytochrome in the light triggers asexual development and represses sexual development in the fungus aspergillus nidulans. this response has been shown to require a phytochrome red/far-red light photoreceptor, fpha, which is cytoplasmic and binds a tetrapyrrole chromophore. fpha exhibits similarities to both plant and bacterial phytochromes.200516243020
cloning and expression analysis of two catalase genes from aspergillus oryzae.fungi contain distinct genes encoding the same class of enzyme that are differentially regulated according to conditions. we cloned two catalase genes, cata and catb, from aspergillus oryzae. the cata gene predicts a 747-amino-acid polypeptide sharing 81% identity with aspergillus fumigatus catalase (cata) and 77% with aspergillus nidulans catalase (cata). the catb gene predicts a 725-amino-acid polypeptide sharing 82% identity with a. fumigatus catalase (catb) and 75% with a. nidulans catalase ...200516233832
cloning and transcription analysis of the aspergillus aculeatus no. f-50 endoglucanase 2 (cmc2) gene.the cmc2 gene, coding for an endoglucanase 2 (cmc2) of aspergillus aculeatus, was cloned using both genomic and cdna libraries, and sequenced. the gene consists of 1230 bp encoding a protein of 410 amino acid residues with a molecular mass of 43,697 da. the cmc2, composed of an n-terminal catalytic domain belonging to the family 5 of glycosyl hydrolases and a c-terminal cellulose-binding domain (cbd) belonging to the family i of cbds, showed identity with other fungal endoglucanases, particularl ...200216233338
aspergillus oryzae palbory encodes a calpain-like protease: homology to emericella nidulans palb and conservation of functional regions.we have cloned and sequenced genomic dna of aspergillus oryzae palbory, orthologue of emericella nidulans palb, which encodes a calpain-like protease modulating a signal transduction pathway during alkaline adaptation. the deduced amino acid sequence of palbory is 70.0% identical to palb over its entire length. the regions with high similarity revealed possible domains important for their function. this is the first step towards understanding the alkaline adaptation mechanism of a. oryzae, which ...199916232641
cloning and functional analysis of the aspergillus oryzae conidiation regulator gene brla by its disruption and misscheduled expression.we cloned the brla gene from aspergillus oryzae genomic dna using the a. nidulans brla gene as a probe. a 3.1-kb ecori-bali genomic dna fragment was cloned and sequenced. the deduced amino acid sequence revealed 70% identity with a. nidulans brla and contained two c2h2 zinc finger motifs in its carboxyl terminus, and the promoter sequence contained a 43-bp highly conserved region, indicating that the cloned gene was an a. oryzae homologue of a. nidulans brla. disruption of the brla gene by homol ...199916232494
hdaa, a major class 2 histone deacetylase of aspergillus nidulans, affects growth under conditions of oxidative stress.histone deacetylases (hdacs) catalyze the removal of acetyl groups from the epsilon-amino group of distinct lysine residues in the amino-terminal tail of core histones. since the acetylation status of core histones plays a crucial role in fundamental processes in eukaryotic organisms, such as replication and regulation of transcription, recent research has focused on the enzymes responsible for the acetylation/deacetylation of core histones. very recently, we showed that hdaa, a member of the sa ...200516215180
nuclear accumulation of the gata factor area in response to complete nitrogen starvation by regulation of nuclear export.both the availability and the quality of nutrients affect cellular functions by controlling gene activity. area, a member of the gata family of transcription factors, globally activates expression of genes involved in nitrogen source utilization in aspergillus nidulans. the quality of the nitrogen source determines the level and activation capacity of area through controls at the level of area mrna stability and by interaction of area with the corepressor nmra. the availability of potential nitr ...200516215172
cloning, expression, and characterization of an oligoxyloglucan reducing end-specific xyloglucanobiohydrolase from aspergillus oligoxyloglucan reducing end-specific xyloglucanobiohydrolase from the filamentous fungus aspergillus nidulans was cloned and expressed in pichia pastoris as a secreted histidine-tagged protein and purified by affinity chromatography. the enzyme acts on xyloglucan oligomers and releases the first two glycosyl residue segments from the reducing end, provided that neither the first glucose nor the xylose attached to the third glucose residue from the reducing end is not further substituted. the ...200516214120
structure-activity relationships and enzyme inhibition of pantothenamide-type pantothenate kinase inhibitors.a set of novel pantothenamide-type analogues of the known staphylococcus aureus pantothenate kinase (sapank) inhibitors, n-pentyl, and n-heptylpantothenamide, was synthesized in three series. the first series of analogues (1-3) were designed as molecular probes of the pank binding site to elucidate important structure-activity relationships (sar). the second series of analogues (4-16) were designed using structural information obtained from the escherichia coli pank (ecpank) structure by targeti ...200616213731
quality control and reference guidelines for clsi broth microdilution susceptibility method (m 38-a document) for amphotericin b, itraconazole, posaconazole, and voriconazole.although standard conditions are available for testing the susceptibilities of filamentous fungi to antifungal agents by the clinical and laboratory standards institute (clsi; formerly national committee for clinical laboratory standards) broth microdilution assay, quality control (qc) mic limits have not been established for any mold-agent combination. this multicenter (eight-center) study documented the reproducibility of tests for one isolate of paecilomyces variotii atcc mya-3630 and 11 othe ...200516207990
increased mesquite gum formation in nodal explants cultures after treatment with a microbial biomass preparation.prosopis laevigata nodal explants cultures were established in murashige and skoog medium. simultaneously these cultures were subjected to stress with biotic elicitors and an environmental factor (temperature increase to promote heat stress) in order to promote and increase exuded mesquite gum production. the biotic elicitors were: aspergillus nidulans and pseudomonas pseudoalcaligenes both used in concentrations of 10, 20 and 30 mg, whereas the environmental condition was different incubation t ...200516198591
nonribosomal peptide synthetase genes in the genome of fusarium graminearum, causative agent of wheat head blight.fungal nonribosomal peptide synthetases (nrpss) are responsible for the biosynthesis of numerous metabolites which serve as virulence factors in several plant-pathogen interactions. the aim of our work was to investigate the diversity of these genes in a fusarium graminearum sequence database using bioinformatic techniques. our search identified 15 nrps sequences, among which two were found to be closely related to peptide synthetases of various fungi taking part in ferrichrome biosynthesis. ano ...200516196211
synthesis of penicillium chrysogenum acetyl-coa:isopenicillin n acyltransferase in hansenula polymorpha: first step towards the introduction of a new metabolic pathway.the enzyme acetyl-coa:isopenicillin n acyltransferase (iat) is a peroxisomal enzyme that mediates the final step of penicillin biosynthesis in the filamentous fungi penicillium chrysogenum and aspergillus nidulans. however, the precise role of peroxisomes in penicillin biosynthesis is still not clear. to be able to use the power of yeast genetics to solve the function of peroxisomes in penicillin biosynthesis, we introduced iat in the yeast hansenula polymorpha. to this purpose, the p. chrysogen ...200516169289
the appearances of autolytic and apoptotic markers are concomitant but differently regulated in carbon-starving aspergillus nidulans ageing, carbon-depleted cultures of aspergillus nidulans strain fgsc 26 progressing apoptotic-type cell death was detected, characterised by increasing numbers of annexin v and tunel stained cells after protoplastation. dapi staining of autolysing mycelia revealed numerous nuclei with elongated, stick-like morphology, which was not observed in surviving hyphal fragments representing a cell population adapted to carbon starvation. apoptotic cell death was also progressing in aging cultures of ...200516165325
nuclear translocation of the heterotrimeric ccaat binding factor of aspergillus oryzae is dependent on two redundant localising signals in a single subunit.the ccaat-binding complex in the aspergillus species, also known as the hap complex, consists of at least three subunits, namely hapb, hapc and hape. each hap subunit contains an evolutionary conserved core domain. recently, we have found that the hapc and hape subunits do not carry a nuclear localisation signal. furthermore, when in complex with hapb, they are transported into the nucleus via a 'piggy back mechanism' in a. nidulans. to extend our findings to other filamentous fungi, we examined ...200516163515
characterization of the oat1 gene of penicillium chrysogenum encoding an omega-aminotransferase: induction by l-lysine, l-ornithine and l-arginine and repression by ammonium.the penicillium chrysogenum oat1 gene, which encodes a class iii omega-aminotransferase, was cloned and characterized. this enzyme converts lysine into 2-aminoadipic semialdehyde, and plays an important role in the biosynthesis of 2-aminoadipic acid, a precursor of penicillin and other beta-lactam antibiotics. the enzyme is related to ornithine-5-aminotransferases and to the lysine-6-aminotransferases encoded by the lat genes found in bacterial cephamycin gene clusters. expression of oat1 is ind ...200516163487
a two-step protocol for efficient deletion of genes in the filamentous ascomycete podospora anserina.deletion of genes in podospora anserina via conventional methods is an inefficient and time-consuming process since homologous recombination occurs normally only at low frequency (about 1%). to improve the efficiency of replacement, we adopted the two-step protocol developed for aspergillus nidulans (chaveroche et al. in nucleic acids res 28:e97, 2000). as a prerequisite, a vector was generated containing a blasticidin resistance cassette for selection in the escherichia coli host strain ks272 ( ...200516160832
circadian rhythms in neurospora crassa: clock gene homologues in analysis of a total of 17 filamentous fungal and yeasts genomes has shown: (1) homologues of frq, wc-1, wc-2, and vvd, key gene components of the neurospora crassa clock, are present in magnaporthe grisea, gibberella zeae, and podospora anserina, suggesting an frq-based oscillator in these organisms; (2) some fungal species that are more distantly related to neurospora, such as rhizopus oryzae do not appear to have frq homologues; (3) many fungal species that do not appear to cont ...200516154782
genetic analysis of the tor pathway in aspergillus nidulans.we identified five genes encoding components of the tor signaling pathway within aspergillus nidulans. unlike the situation in saccharomyces cerevisiae, there is only a single tor kinase, as in plant and animal systems, and mutant phenotypes suggest that the tor pathway plays only a minor role in regulating nitrogen metabolism.200516151253
generation and phenotypic characterization of aspergillus nidulans methylisocitrate lyase deletion mutants: methylisocitrate inhibits growth and conidiation.propionate is a very abundant carbon source in soil, and many microorganisms are able to use this as the sole carbon source. nevertheless, propionate not only serves as a carbon source for filamentous fungi but also acts as a preservative when added to glucose containing media. to solve this contradiction between carbon source and preservative effect, propionate metabolism of aspergillus nidulans was studied and revealed the methylcitrate cycle as the responsible pathway. methylisocitrate lyase ...200516151139
fundamental contribution of beta-oxidation to polyketide mycotoxin production in planta.seed contamination with polyketide mycotoxins, including aflatoxin (af) and sterigmatocystin (st) produced by aspergillus spp., is an agricultural, economic, and medical issue worldwide. acetyl-coa, the fundamental building block of all known fungal polyketides, is generated by a large number of biochemical pathways, including beta-oxidation of fatty acids and glycolysis of sugars. we present several lines of evidence to support a major role for seed fatty acids in formation of af and st in a. f ...200516134890
alkaline ph-induced up-regulation of the afp gene encoding the antifungal protein (afp) of aspergillus giganteus is not mediated by the transcription factor pacc: possible involvement of calcineurin.the afp gene encoding the antifungal protein (afp) of aspergillus giganteus has a prototypical alkaline gene expression pattern, which suggests that the gene might be under the control of the ambient ph-dependent zinc-finger transcription factor pacc. this notion is corroborated by the presence in the upstream region of afp of two putative pacc binding sites, afpp1 and afpp2, which are specifically recognised by the pacc protein of a. nidulans in vitro. however, in this report we provide several ...200516133167
deciphering the model pathogenic fungus cryptococcus neoformans.cryptococcus neoformans is a basidiomycete fungal pathogen of humans that has diverged considerably from other model fungi such as neurospora crassa, aspergillus nidulans, saccharomyces cerevisiae and the common human fungal pathogen candida albicans. the recent completion of the genome sequences of two related c. neoformans strains and the ongoing genome sequencing of three other divergent cryptococcus strains with different virulence phenotypes and environmental distributions should improve ou ...200516132036
the snpa, a temperature-sensitive suppressor of npga1, encodes the eukaryotic translation release factor, erf1, in aspergillus nidulans.the npga1 mutation causes defects in the outer layer of the cell wall resulting in a colorless colony. in this study, a temperature-sensitive suppressor of npga1 named snpa was isolated by uv mutagenesis. the suppressing mutant showed pleiotropic phenotypes in cellular structure and developmental processes when incubated at a temperature of 37 degrees c or above. at 37 degrees c, multiple germ tubes emerged from germinating conidia. moreover, at 42 degrees c conidia germination was delayed more ...200516125337
the flug-brla pathway contributes to the initialisation of autolysis in submerged aspergillus nidulans cultures.the flug gene proved to be essential in the initialisation of autolysis in aspergillus nidulans (teleomorph emericella nidulans) cultures, while a loss-of-function mutation in only one out of the flbb-e genes had only minor effects on autolysis. in contrast to its important role in sporulation, brla regulated only some, but not all, elements of the autolytic process. the tightly coupled autolytic events (chitinase and proteinase production, hyphal fragmentation, disorganisation of pellets, autol ...200516121561
[possible sources of aspergilla infection in a hematological hospital].to investigate spread, species spectrum, quantity of aspergilla spores in the air of a hematological hospital.200516116914
benznidazole-induced genotoxicity in diploid cells of aspergillus nidulans.genotoxic effects of benznidazole were studied by the induction of homozygosis of genes previously present in heterozygous. ut448//a757 diploid strain was used in the benznidazole's recombinagenesis test. although toxic effects on growth of colonies were not observed, 75 and 100 microm benznidazole induced an increasing of mitotic recombination events in diploid strain. results were related to the induction of chromosomal breaks by the antiparasitic drug.200516113877
growth control and polarization.filamentous fungi and yeasts both undergo polar growth. in saccharomyces cerevisiae, where the mechanisms for polar growth are well-understood, polarity requires three steps: establishment of cortical markers specifying the site of bud emergence; relaying the bud site information via the cdc42 rho gtpase module; and recruitment of the morphogenetic machinery needed to remodel the cell surface to the specified site. comparison of the genomes of aspergillus fumigatus, a. nidulans and a. oryzae wit ...200516110788
what the aspergillus genomes have told us.the sequencing and annotation of the genomes of the first strains of aspergillus nidulans, aspergillus oryzae, and aspergillus fumigatus will be seen in retrospect as a transformational event in aspergillus biology. with this event the entire genetic composition of a. nidulans, the sexual experimental model organism of the genus aspergillus, a. oryzae, the food biotechnology organism which is the product of centuries of cultivation, and a. fumigatus, the most common causative agent of invasive a ...200516110785
role of the spindle-pole-body protein apsb and the cortex protein apsa in microtubule organization and nuclear migration in aspergillus nidulans.nuclear migration and positioning in aspergillus nidulans depend on microtubules, the microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are apsa and apsb. in apsa and apsb mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. we studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. because apsa l ...200516105883
arrestin-related proteins mediate ph signaling in fungi.metazoan arrestins bind to seven-transmembrane (7tm) receptors to regulate function. aspergillus nidulans palf, a protein involved in the fungal ambient ph signaling pathway, contains arrestin n-terminal and c-terminal domains and binds strongly to two different regions within the c-terminal cytoplasmic tail of the 7tm, putative ph sensor palh. upon exposure to alkaline ambient ph, palf is phosphorylated and, like mammalian beta-arrestins, ubiquitinated in a signal-dependent and 7tm protein-depe ...200516099830
aspergillus nidulans swok encodes an rna binding protein that is important for cell polarity.the aspergillus nidulans swok1 mutant is defective in polarity maintenance when grown at restrictive temperature (38 degrees c). upon germination, the mutant extends a primary germ tube that swells to an enlarged, non-uniform cell with pronounced wall thickenings. the mutant is fully restored to wild-type growth when transformed with a plasmid containing the an5802.2 orf as designated in the broad institute a. nidulans sequence database. genetic mapping places swok in the same region of chromoso ...200516098776
the ccaat-binding complex of eukaryotes: evolution of a second nls in the hapb subunit of the filamentous fungus aspergillus nidulans despite functional conservation at the molecular level between yeast, a.nidulans and human.the heterotrimeric ccaat-binding complex is evolutionarily conserved in eukaryotic organisms, including fungi, plants and mammals. in the filamentous fungus aspergillus nidulans, the corresponding complex was designated ancf (a.nidulans ccaat-binding factor). ancf consists of the subunits hapb, hapc and hape. all three subunits are necessary for dna binding. hapb contains two putative nuclear localisation signal sequences (nlss) designated nls1 and nls2. previously, it was shown that only nls2 w ...200516098534
comparative substrate recognition by bacterial and fungal purine transporters of the nat/ncs2 family.we compared the interactions of purines and purine analogues with representative fungal and bacterial members of the widespread nucleobase-ascorbate transporter (nat) family. these are: uapa, a well-studied xanthine-uric acid transporter of a. nidulans, xut1, a novel transporter from c. albicans, described for the first time in this work, and ygfo, a recently characterized xanthine transporter from e. coli. using transport inhibition experiments with 64 different purines and purine-related analo ...200516096268
cloning and functional characterization of two bacterial members of the nat/ncs2 family in escherichia coli.the coding potential of the genome of e. coli k-12 includes ygfo and yice, two members of the evolutionarily conserved nat/ncs2 transporter family that are highly homologous to each other (45% residue identity) and closely related to uapa of aspergillus nidulans, a most extensively studied microbial member of this family. ygfo and yice were cloned from the genome, over-expressed extrachromosomally and assayed for uptake of [(3)h]xanthine and other nucleobases, in e. coli k-12, under conditions o ...200516096267
a microtubule associated protein (hnudc) binds to the extracellular domain of thrombopoietin receptor (mpl).human nudc (hnudc) was initially characterized as a nuclear migration protein based on the similarity of its c-terminus to that of fungal nudc from aspergillus nidulans. however, hnudc is a 331 amino acid protein whereas fungal nudc is 198 amino acids in length. the extra n-terminal portion of hnudc has no known function or homology to other proteins. in this study, we report the binding of hnudc to the extracellular domain of the thrombopoietin receptor (mpl) as detected by the yeast two-hybrid ...200516088917
the pkab gene encoding the secondary protein kinase a catalytic subunit has a synthetic lethal interaction with pkaa and plays overlapping and opposite roles in aspergillus nidulans.filamentous fungal genomes contain two distantly related cyclic amp-dependent protein kinase a catalytic subunits (pkas), but only one pka is found to play a principal role. in aspergillus nidulans, pkaa is the primary pka that positively functions in vegetative growth and spore germination but negatively controls asexual sporulation and production of the mycotoxin sterigmatocystin. in this report, we present the identification and characterization of pkab, encoding the secondary pka in a. nidul ...200516087751
expression of asexual developmental regulator gene abaa is affected in the double mutants of classes i and ii chitin synthase genes, chsc and chsa, of aspergillus nidulans.the chsa and chsc encode classes ii and i chitin synthases, respectively, of the filamentous fungus aspergillus nidulans. the deltachsa deltachsc double mutants (deltaac mutants) show defects in asexual development: a striking reduction in the number of conidiophores and aberrant conidiophore morphology. here, we examined the involvement of regulatory genes for asexual development (brla, abaa, and meda) in the conidiation defects of the deltaac mutants. spatial expression patterns of brla, abaa, ...200516082523
the csnd/csne signalosome genes are involved in the aspergillus nidulans dna damage response.the signalosome (csn) is a conserved multiprotein complex involved in regulation of eukaryotic development and is also required to activate ribonucleotide reductase for dna synthesis. in aspergillus nidulans, csnd/csne are key regulators of sexual development. here, we investigated whether the csnd/csne genes are involved in the dna damage response in this fungus. the growth of the csnd/csne deletion mutants was reduced by subinhibitory concentrations of hydroxyurea, camptothecin, 4-nitroquinoli ...200516079239
regulation of secondary metabolism in filamentous fungi.fungal secondary metabolites are of intense interest to humankind due to their pharmaceutical (antibiotics) and/or toxic (mycotoxins) properties. in the past decade, tremendous progress has been made in understanding the genes that are associated with production of various fungal secondary metabolites. moreover, the regulatory mechanisms controlling biosynthesis of diverse groups of secondary metabolites have been unveiled. in this review, we present the current understanding of the genetic regu ...200516078891
rnase p cleaves transient structures in some riboswitches.rnase p from escherichia coli cleaves the coenzyme b12 riboswitch from e. coli and a similar one from bacillus subtilis. the cleavage sites do not occur in any recognizable structure, as judged from theoretical schemes that have been drawn for these 5' utrs. however, it is possible to draw a scheme that is a good representation of the e. coli cleavage site for rnase p and for the cleavage site in b. subtilis. these data indicate that transient structures are important in rnase p cleavage and in ...200516061811
identification and molecular cloning of a gene encoding phospholipase a2 (plaa) from aspergillus nidulans.the plaa gene encoding a protein that contains the cytosolic phospholipase a(2) (cpla(2)) motif is cloned for the first time from the filamentous fungus, aspergillus nidulans. the translated 837 amino acid protein product of plaa comprises conserved lipase regions that are present in most mammalian cpla(2) homologs. high expression of plaa was observed in glucose-lactose medium by northern blot analyses. deletion mutants of plaa grew and formed conidia similar to the wild-type strain, but showed ...200516051517
lysine is catabolized to 2-aminoadipic acid in penicillium chrysogenum by an omega-aminotransferase and to saccharopine by a lysine 2-ketoglutarate reductase. characterization of the omega-aminotransferase.the biosynthesis and catabolism of lysine in penicillium chrysogenum is of great interest because these pathways provide 2-aminoadipic acid, a precursor of the tripeptide delta-l-2-aminoadipyl-l-cysteinyl-d-valine that is an intermediate in penicillin biosynthesis. in vivo conversion of labelled l-lysine into two different intermediates was demonstrated by hplc analysis of the intracellular amino acid pool. l-lysine is catabolized to 2-aminoadipic acid by an omega-aminotransferase and to sacchar ...200516049680
virulence comparisons of aspergillus nidulans mutants are confounded by the inflammatory response of p47phox-/- mice.while investigating the requirement for phagosomal alkalinization in the host defense against pulmonary aspergillosis, we observed high morbidity of p47(phox)(-/-) mice infected with ph-insensitive aspergillus nidulans mutants despite a paucity of fungal growth. fatal infection also resulted from a normally avirulent p-aminobenzoate auxotroph. this demonstrates that p47(phox)(-/-) murine immunity contributes significantly to a. nidulans lethality. these data have wider implications for microbial ...200516041040
aspergillus cyclooxygenase-like enzymes are associated with prostaglandin production and virulence.oxylipins comprise a family of oxygenated fatty acid-derived signaling molecules that initiate critical biological activities in animals, plants, and fungi. mammalian oxylipins, including the prostaglandins (pgs), mediate many immune and inflammation responses in animals. pg production by pathogenic microbes is theorized to play a role in pathogenesis. we have genetically characterized three aspergillus genes, ppoa, ppob, and ppoc, encoding fatty acid oxygenases similar in sequence to specific m ...200516040966
in vitro activation, purification, and characterization of escherichia coli expressed aryl-alcohol oxidase, a unique h2o2-producing enzyme.aryl-alcohol oxidase (aao), a flavoenzyme with unique spectral and catalytic properties that provides h2o2 for fungal degradation of lignin, has been successfully activated in vitro after escherichia coli expression. the recombinant aao (aao*) protein was recovered from inclusion bodies of e. coli w3110 transformed with pflag1 containing the aao cdna from pleurotus eryngii. optimization of in vitro refolding yielded 75% active enzyme after incubation of aao* protein (10 microg/ml) for 80 h (at 1 ...200616039872
cloning and functional analysis of the orotidine-5'-phosphate decarboxylase gene (pbrura3) of the pathogenic fungus paracoccidioides brasiliensis.a genomic clone encoding the paracoccidioides brasiliensis orotidine monophosphate decarboxylase gene (pbrura3) was isolated by screening a subgenomic plasmid dna library of this fungus, using a pcr amplification product of the gene as a probe. sequence analysis revealed that the gene contains an open reading frame of 855 bp with a single intron (162 bp), and encodes a putative 285 amino acids polypeptide of estimated molecular weight 31.1 kda and isoelectric point 6.5. the deduced amino acid se ...200516034822
comparing artificial and natural selection in rate of adaptation to genetic stress in aspergillus an experimental study of adaptation to negative pleiotropic effects of a major fungicide resistance mutation in the filamentous fungus aspergillus nidulans we have investigated the relative effectiveness of artificial selection vs. natural selection on the rate of compensatory evolution. using mycelial growth rate as a fitness measure, artificial selection involved the weekly transfer of the fastest growing sector onto a fresh plate. natural selection was approximated by transferring random s ...200516033548
biodegradation study of crop residues as affected by exogenous inorganic nitrogen and fungal inoculants.the comparative decomposition of chickpea residue, and chopped and unchopped wheat straw was investigated in pits for 120 days. microbial biomass, humus, c/n ratio, ph, electrical conductivity (ec), dehydrogenase, alkaline phosphatase, cellulase, xylanase, total phenol and soluble protein were determined to assess their response to the addition of inorganic nitrogen and mixed fungal inoculum of aspergillus nidulans, phanerochaete chrysosporium and trichoderma viride. the evaluation of physico-ch ...200516028202
autoregulated, bidirectional and multicistronic gas-inducible mammalian as well as lentiviral expression vectors.we present a novel set of autoregulated, bidirectional and multicistronic mammalian as well as lentiviral expression vectors which enable transgene expression fine-tuning by gaseous acetaldehyde. the acetaldehyde-inducible regulation (air) technology capitalizes on aspergillus nidulans components evolved to convert ethanol into metabolic energy. air is based on functional interaction of the fungal transactivator alcr and alcr-specific chimeric promoters (p(air)) which drive desired transgene exp ...200516026881
discrepancies between recombination frequencies and physical distances in aspergillus nidulans: implications for gene identification.a rapid route to gene molecular identification involves using recombination frequencies in locating mutational sequence changes. we describe a case where the recombination frequency is deceptively low, probably reflecting centromere proximity. recombination frequencies are greatly reduced near the centromeres on the right arms of chromosomes iii and iv of aspergillus nidulans.200516020782
characterization of the ferrichrome a biosynthetic gene cluster in the homobasidiomycete omphalotus olearius.under iron deprivation omphalotus olearius was found to produce the hydroxamate siderophore ferrichrome a. a gene cluster consisting of three genes: fso1, a nonribosomal peptide synthetase whose expression is enhanced in the absence of iron; omo1, a l-ornithine-n(5)-monooxygenase; and ato1, an acyltransferase probably involved in the transfer of the methylglutaconyl residue to n(5)-hydroxyorinithine was identified. the fso1 sequence is interrupted by 48 introns and its derived protein sequence h ...200516019163
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