Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| characterization of a new choline locus in aspergillus nidulans and its significance for choline metabolism. | 1978 | 376401 | |
| multiple independent control mechanisms affecting the acetamidase of aspergillus nidulans. | the acetamidase of aspergillus nidulans is induced by sources of acetyl coa, benzoate and benzamide and by beta-alanine and other omega-amino acids. the effects of these groups of inducers are appromimately additive. the cis-acting control site mutant, amdi9, affects induction by sources of acetyl-coa specifically. lesions in the amdr and gata genes affect induction by omega-amino acids specifically. mutations in the amda gene can lead to elevated acetamidase levels which still respond to the va ... | 1978 | 353500 |
| preparation of large molecular weight dna from the fungus aspergillus nidulans. | 1978 | 353226 | |
| distribution of autolysins in hyphae of aspergillus nidulans: evidence for a lipid-mediated attachment to hyphal walls. | preparations of broken aspergillus nidulans hyphae contained both free and wall-bound autolysins. the bound enzymes were not solubilized by 8 m licl or neutral or anionic detergents; they were readily detached from walls by a cationic detergent or by autodigestion. once detached, the enzymes did not reassociate with wall to give salt-resistant complexes. six enzymes hydrolyzing wall polymers were bound to the envelope, and the same activities were also detected among soluble proteins in the cyto ... | 1978 | 357422 |
| reversion in variants from a duplication strain of aspergillus nidulans. | strains of aspergillus nidulans with a chromosome segment in duplicate, one in normal position and one translocated to another chromosome, are unstable at mitosis. in addition to variants which result from deletions in either of the duplicate segments, which usually have improved morphology, they produce variants with deteriorated morphology. three deteriorated variants reverted frequently to parental type morphology, both spontaneously and after ultra-violet treatment. of six reversions analyse ... | 1978 | 362154 |
| gaba transaminase provides an alternative route of beta-alanine synthesis in aspergillus nidulans. | three unlinked genes where mutation can lead to d(+)-pantothenic acid auxotrophy in aspergillus nidulans have been identified. pantoa is probably the structural gene for pantothenate synthetase (ec 6.3.2.1) whilst pantob and pantoc are involved in the syntheses of d-pantoic acid and beta-alanine, respectively. a pantoc- mutant is tentatively considered to be blocked in conversion of 5,6-dihydrouracil to beta-ureidopropionate. an alternative route of beta-alanine biosynthesis occurs by the transa ... | 1978 | 355840 |
| on the mechanisms of induced somatic recombination by certain fungicides in aspergillus nidulans. | four fungicides interfered with the segregation of chromosomes at mitosis of aspergillus nidulans by increasing the somatic recombination, shown as colour sectors in green colonies, in a strain heterozygous for spore colour mutations. in an attempt to discover the mechanisms by which these fungicides increased the somatic recombination, a prototrophic diploid strain, heterozygous for colour and several other appropriate markers in all chromosomes, was used which enabled the detection and classif ... | 1978 | 357961 |
| pyridoxine and its relation to lipids. studies with pyridoxineless mutants of aspergillus nidulans. | the effect of pyridoxine deficiency on fat metabolism was studied using mutant strains of aspergillus nidulans requiring pyridoxine for growth. under pyridoxine deficiency the mutants exhibited increased levels of total lipid, sterols, phospholipids, and triacylglycerols. total fatty acids were found to decrease with pyridoxine deficiency. an increase in saturated fatty acids and decrease in unsaturated fatty acids were seen with deficiency. pyridoxine deficiency also increased lower carbon chai ... | 1978 | 361929 |
| a quick method for testing recessive lethal damage with a diploid strain of aspergillus nidulans. | a simple method capable of detecting recessive lethal damage in a diploid strain of aspergillus nidulans is described. the method scores the recessive lethals on the 1st, the 3rd and the 5th chromosomes, which represent about 40% of the total map of a. nidulans. two examples of induced lethals, with ultraviolet irradiation and methyl methanesulfonate are shown. the frequency of lethals may reach 36% of the total population with uv irradiation. | 1978 | 362184 |
| low repetitive dna content in aspergillus nidulans. | dna-dna reassociation experiments show that the genome of aspergillus nidulans consists of approximately 97 to 98 percent unique and 2 to 3 percent reiterated sequences. the reiterated dna sequences have a complexity of about 11,000 base pairs and are repeated approximately 60 times per haploid genome. ribosomal rna-dna hybridization experiments indicate that most of the repetitive dna codes for ribosomal rna. | 1978 | 362530 |
| identification of a gene for beta-tubulin in aspergillus nidulans. | 1978 | 363278 | |
| isolation of dna from aspergillus nidulans. | a procedure for isolation of dna from aspergillus nidulans on a preparative scale is described. mechanical disruption of lyophilized material in high-salt medium and treatment with proteinase k, followed by sedimentation of the lysate into saturated csc1 solution yielded pure, highly polymerized dna. | 1978 | 364902 |
| aspects of the molecular biology of lipoamide dehydrogenase. | 1978 | 367117 | |
| an "up-promotor" mutation affecting the acetamidase of aspergillus nidulans. | a derivative of an area200 strain of aspergillus nidulans selected for strong growth on acetamide as the sole nitrogen source was found to have a mutation, amd-18, closely linked to amds, the acetamidase structural gene. this mutation results in 2--3 fold higher acetamidase activities than wildtype strains in uninduced as well as induced cultures. the effects of the amd-18 mutation are superimposed on the effects of other regulatory mutations affecting the acetamidase. the amd-18 mutation is cis ... | 1978 | 368568 |
| restriction endonuclease cleavage map of mitochondrial dna from aspergillus nidulans. | mitochondrial dna of the ascomycete fungus aspergillus nidulans, a circular molecule of 31 500 base pairs, is cleaved by restriction endonucleases eco r i, hind ii, hind iii and bgl ii into 3, 7, 9 and 5 fragments, respectively. the relative positions of the cleavage sites could be mapped by analysis of fragments obtained by double enzyme digestions of whole dna and by complete and partial redigestion of isolated restriction fragments. | 1978 | 345242 |
| mutations in nira gene of aspergillus nidulans and nitrogen metabolism. | 1978 | 347305 | |
| [use of a pyrimidine-dependent mutant for effective labeling of the dna of aspergillus nidulans]. | incorporation of the radioactive label from pyrimidines into rna and dna of an aspergillus nidulans pyrimidine-dependent mutant was studied. the label from [14c2]uridine was incorporated at the highest rate into both fractions of nucleic acids from a. nidulans of the wild type and pyr-mutant. the content of the label in the dna of the pyr-mutant was several times higher than that in the wild type dna. therefore, pyr-mutants can be used in order to study molecular-genetic processes in the cells o ... | 1978 | 370508 |
| polyamine stimulation of in vivo rates of macromolecular synthesis in a putrescine auxotroph of aspergillus nidulans. | 1978 | 340271 | |
| meiotic recombination in a duplication strain of aspergillus nidulans. | 1978 | 344133 | |
| the effects of coumarin on the frequency of deletions in a duplication strain of aspergillus nidulans. | strains of a. nidulans with a chromosome segment in duplicate show instability resulting from deletions in either of the duplicate segments. in dp (i, ii) strains, with the terminal segment of ir attached terminally to iir, spontaneous deletions occur most frequently, though not exclusively, from the translocated segment. coumarin, at concentrations which did not affect viability viability or growth rate, enhanced the instability of dp (i, ii) strains by selectively increasing only the deletion ... | 1978 | 345093 |
| supersuppressors in aspergillus nidulans. | simultaneous reversion of mutations in two different aspergillus nidulans loci ada and metg was found to be due monogenic suppressor mutations. preliminary evidence for the existance of supersuppressors in a. nidulans is presented. | 1978 | 345096 |
| sporulation competence in aspergillus nidulans: a role for iron in development. | there is a difference in the response of dna from mycelial extracts of aspergillus nidulans to hot acid hydrolysis depending upon the state of sporulation competence. the dna in incompetent culture mycelia is not hydrolyzable while the dna in competent culture is hydrolyzable. the inhibition of dna hydrolysis is due to the presence of iron. although the concentration of iron decreases in mycelia during growth, there is sufficient iron present in competent mycelia to inhibit dna hydrolysis. the c ... | 1978 | 350417 |
| the nature of an initiator constitutive mutation in aspergillus nidulans. | 1978 | 351427 | |
| the genetic control of the molybdoflavoproteins in aspergillus nidulans. iv. a comparison between purine hydroxylase i and ii. | the purine hydroxylases i and ii of aspergillus nidulans [previously called xanthine dehydrogenases i and ii: scazzocchio, holl and foguelman, eur. j. biochem. 36, 428--445 (1973)] have been studied in crude extracts. the two enzymes differ in their substrate specificities, purine hydroxylase ii being able to accept nicotinate as a substrate and unable to hydroxylate xanthine. the kinetics of inhibition with allopurinol and oxypurinol are also different, the two analogues being pseudo-irreversib ... | 1978 | 363427 |
| a mutation in the xanthine dehydrogenase (purine hydroxylase i) of aspergillus nidulans resulting in altered specificity. implications for the geometry of the active site. | a point mutation in the structural gene for purine hydroxylase i (xanthine dehydrogenase) of aspergillus nidulans results in several dramatic pleiotropic effects. the mutant enzyme oxidises 2-hydroxypurine at position 6 rather than 8, shows a 70-fold reduction in the v for hypoxanthine, and loses the ability to accept xanthine as a substrate. allopurinol, a powerful pseudoirreversible inhibitor of the wild type enzyme, behaves as a good substrate of the mutant enzyme. we propose that the substra ... | 1978 | 363429 |
| [methodological approaches to the study of ultraviolet irradiation--induced dna degradation in mycelial fungi using the example of aspergillus nidulans]. | 1978 | 363179 | |
| interaction of thiabendazole with fungal tubulin. | thiabendazole, 2-(4'-thiazolyl)benzimidazole, at 80 micrometer completely inhibits mitosis in hyphae of aspergillus nidulans, growing in liquid culture. dna and rna synthesis and mycelial growth are only partially inhibited at this concentration. binding studies with cell-free mycelial extracts from penicillium expansum showed that thiabendazole competitively inhibits [14c]carbendazim binding to tubulin, which suggests that the antimitotic activity of thiabendazole is based on interference with ... | 1978 | 361093 |
| detection of mutagens produced by fungi with the salmonella typhimurium assay. | forty-one fungal isolates (one isolate per species) representing common plant pathogens and food crop contaminants were grown on sterile, polished rice and assayed for mutagenic activity in the salmonella typhimurium-microsome system. initially, single doses of aqueous and chloroform extracts of the moldy rice were assayed against the ta100 tester strain by incorporating extracts into the growth medium and by applying small quantities on disks placed on the agar surface. suspected activity was e ... | 1978 | 354528 |
| reduced expression of a distal gene of the prn gene cluster in deletion mutants of aspergillus nidulans: genetic evidence for a dicistronic messenger in an eukaryote. | the prn gene cluster involved in l-proline catabolism in aspergillus nidulans, has the gene order prna-prnd-regulatory region-prnb-prnc. prnb, prnd, and prnc specify proline permease, proline oxidase, and delta1-pyrroline-5-carboxylate (p5c) dehydrogenase, respectively. prna is probably a positive regulatory gene whose product is necessary for expression of the prn activities. proline induces proline permease and p5c dehydrogenase in prnd- mutants which lack proline oxidase, showing that proline ... | 1978 | 355839 |
| cell cycle mutants. | 1978 | 106766 | |
| catabolite repression in aspergillus nidulans; the role of glutamine synthetase. | a mutant (nit8) with a lowered activity of glutamine synthetase (gs) was isolated in aspergillus nidulans. the levels of gs and of an arginine catabolic enzyme, ornithine transaminase (ota) were assayed under a variety of growth conditions leading to repression, depression and induction of ota in the wild type, nit8 and several regulatory mutants. the results obtained appear to exclude the possibility of involvement of gs in the regulation of arginine catabolism in a. nidulans. | 1978 | 86277 |
| phycobiliprotein synthesis in protoplasts of the unicellular cyanophyte, anacystis nidulans. | stable and metabolically active protoplasts were prepared from the unicellular cyanophyte, anacystis nidulans, by enzymatic digestion of the cell wall with 0.1% lysozyme. the yield of protoplasts from intact algal cells was approx. 50%. incorporation of l-[u-14c]leucine into cold trichloroacetic acid-insoluble material from protoplasts preparations was linear for 1.5 h and continued for an additional 2.5 h. incorporation of radiolabeled leucine into hot trichloroacetic acid-insoluble material fr ... | 1978 | 96857 |
| nitrate assimilation in fungi. | 1978 | 157059 | |
| mitochondrial atpase complex of aspergillus nidulans and the dicyclohexylcarbodiimide-binding protein. | the dicyclohexylcarbodiimide-binding protein of aspergillus nidulans has been identified as the smallest subunit of the mitochondrial atpase complex, and has a molecular weight of approximately 8000. it is extractable from whole mitochondria and from the purified enzyme in neutral chloroform/methanol, contains 30% polar amino acids, and the n-terminal amino acid has been identified as tyrosine. using a double-labelling technique in the absence and presence of cycloheximide, followed by immunopre ... | 1979 | 157278 |
| adenosine triphosphatase of aspergillus nidulans: existence of isoenzymes of ca2+-atpase. | ca2+-atpase activity increased five- to six fold when the cells were subjected to growth at 37 degrees c in protein hydrolysate-supplemented media as compared to that of the cells grown in minimal media. one major isoenzyme and one minor isoenzyme were present in minimal-medium-grown cells while two major isoenzymes were present in the cells grown in protein-supplemented media. when the cells were subjected to heat stress (43 degrees c), they exhibited significantly decreased activity as compare ... | 1979 | 158522 |
| short-term tests for carcinogens and mutagens. | 1979 | 159413 | |
| mechanism of action of monoketo-organomycin, cystaurimycin and their performic acid-oxidized modifications. ii. inhibition of mitochondrial atpase activity in aspergillus nidulans and identification of the performic acid-oxidized modifications-binding protein. | 1979 | 159889 | |
| effect of growth temperature on lipid and fatty acid compositions in the blue-green algae, anabaena variabilis and anacystis nidulans. | the lipid composition was affected by growth temperature in anacystis nidulans, but was not in anabaena variabilis. a. variabilis contained fatty acids of 18 and 16 carbon atoms, which were localized at 1- and 2-positions, respectively, of the glycerol moiety of lipids. desaturation of c18 acids was affected by the growth temperature. a. nidulans contained fatty acids of 14, 16 and 18 carbon atoms. monounsaturated and saturated acids were esterified mainly to 1- and 2-position, respectively. des ... | 1979 | 104734 |
| characterization of antigens from aspergillus fumigatus. iii. comparison of antigenic relationships of clinically important aspergilli. | antigenic relationships between strains of aspergillus fumigatus, aspergillus fumigatus var. elipticus, aspergillus phialiseptus, aspergillus flavus, and aspergillus niger were analyzed by fused rocket immunoelectrophoresis and by skin tests. seventy-three to 89 % of the numbers of antigens detected between strains and species of the a. fumigatus series were shared. the degree of sharing between antigens of a. flavus, a. fumigatus series, and a. niger was much lower and ranged from 19 to 35 %. i ... | 1979 | 92906 |
| further characterization of the reduced nicotinamide adenine dinucleotide phosphate: nitrate oxidoreductase in aspergillus nidulans. | the reduced nicotinamide adenine dinucleotide phosphate (nadph):nitrate oxidoreductase (ec 1.6.6.2) from aspergillus nidulans wild-type bi-1 was purified by means of salt fractionation, gel filtration, affinity chromatography, and polyacrylamide gel electrophoresis. enzyme which was adsorbed on cibacron blue agarose could be eluted with 2 mm nadph or 2 mm oxidized nadp (nadp(+)), the former being about three times more effective than the latter. about half the total nadph:nitrate reductase activ ... | 1979 | 33144 |
| photoreactivation of ultraviolet irradiated blue-green alga: anacystis nidulans and cyanophage as-1. | ultraviolet (uv) inactivation and photoreactivation of anacystis nidulans and cyanophage as-1 was studied at different wavelengths. uv inactivation of free phage particles and one and two hour host-phage complexes (intracellular phages) were exponential. uv resistance of plaque forming units was attained at the latter phase of latent period. black, blue and white lights were able to photoreactivate the uv irradiated a. nidulans whereas green, yellow and red lights were not. however, incubation o ... | 1979 | 110290 |
| [effect of lysozyme, ethylenediaminetetraacetate, magnesium and mannittol on spheroplast formation in anacystis nidulans]. | three periods (the lag period and periods of intensive and decelerated spheroplast formation) can be detected in the action of lysozyme on the cells of anacystis nidulans; this seems to be due to peculiarities in the cell wall structure of the cyanobacterium and heterogeneity of the culture. edta at concentrations of 0.175--0.7 mm has effect on the duration of the lag period but increases the rate of spheroplast formation during the subsequent periods. however, the action of edta in complex with ... | 1979 | 113653 |
| [fungi in pulmonary pathology]. | the author presents the most frequently observed pulmonary infections due to some opportunistic fungi (yeast, aspergillus, mucor). he describes the criterial for a correct diagnosis of pulmonary mycosis. | 1979 | 114435 |
| role of aspergillus and candida species in allergic bronchopulmonary mycoses. a comparative study. | allergic bronchopulmonary aspergillosis (abpa) and allergic bronchopulmonary candidiasis (abpc) has been diagnosed in 20 and 13 cases respectively with one case in common, on the basis of laboratory and clinical findings. most of the abpa cases (60%) diagnosed had an early onset of respiratory symptoms, i.e. below the age of 30 years, while most of abpc cases (69%) had a late onset of respiratory symptoms, i.e. after the age of 30 years. the precipitin bands in abpa and abpc were r-type and h-ty ... | 1979 | 118528 |
| an iron-containing superoxide dismutase from anacystis nidulans. | superoxide dismutase (sod) was isolated and purified from anacystis nidulans to near electrophoretic homogeneity. the enzyme has a molecular weight of 37,500, as determined by gel filtration and sds-gel electrophoresis. the enzyme molecule consists of two subunits of identical molecular weight. proton-induced x-ray elemental analysis (pixe) showed that the sod of a. nidulans is an iron-containing enzyme; the fe:enzyme mol ratio was found to be 1. the epr spectra indicated that the active center ... | 1979 | 222743 |
| the dark respiration of anacystis nidulans. production of hcn from histidine and oxidation of basic amino acids. | the basic amino acids, l-arginine, l-lysine, lo-irnithine, and to a lesser extent l-histidine, strongly stimulate the o2 uptake of cell suspensions of the blue-green alga or cyanobacterium anacystis nidulans. in the case of l-histidine, the extra o2 consumption is associated with the formation in vivo of small amounts of hcn, particularly in an atmosphere of o2. the enzyme responsible for both the stimulated o2 uptake with the basic amino acids and the formation of hcn from histidine has been is ... | 1979 | 223652 |
| phenotypic changes in the chemistry of aspergillus nidulans: influence of culture conditions on mycelial composition. | a quantitative study was made of macromolecular (nucleic acids, protein), carbohydrate and mineral (magnesium, potassium and phosphorus) components of aspergillus nidulans in glucose limited chemostat cultures, under varying conditions of dilution rate, temperature, ph and nacl concentration. the overall mineral content showed greatest variation in response to changes in culture salinity, which also affected the mycelial carbohydrate content. concomitant and opposite changes in the content of ca ... | 1979 | 44181 |
| factors affecting protein synthesis during biotin deficiency in aspergillus nidulans. | biotin deficiency in aspergillus nidulans resulted in a 70% increase of the protein content and increased levels of free and bound aspartate, glutamate, serine, leucine and methionine. likewise, the activities of nadp+ glutamate dehydrogenase, nad+ gluatmate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were significantly increased. the total rna content increased while the dna content was unaffected. the rrna/trna ratio remained higher in biotin-deficient cells. supplem ... | 1979 | 43277 |
| identification of a gene for alpha-tubulin in aspergillus nidulans. | 1979 | 378391 | |
| the ability of ionizing radiations of different let to induce chromosomal deletions in aspergillus nidulans. | conidia, derived from a strain of aspergillus nidulans known to carry a specific chromosomal duplication, were irradiated. the duplicated segment had genetic markers, which, when eliminated from the genome, allowed the easy detection of deletion mutants. survival curves derived following 15 mev electron and gamma-ray irradiation were characterised by the presence of an appreciable shoulder, whilst 50 kvp x-rays gave a much smaller shoulder. irradiation with beta-particles and alpha-particles gav ... | 1979 | 375074 |
| induced segregation in interspecific hybrids of aspergillus nidulans and aspergillus rugulosus obtained by protoplast fusion. | interspecific hybrids produced by polyethylene glycol induced fusion of protoplasts from auxotrophic mutants of aspergillus nidulans and aspergillus rugulosus were grown in the presence of the recombinogens benomyl and chloral hydrate to stimulate segregation. the a. nidulans parental strains used had a known genetic marker in each linkage group. hybrids grown on complete medium containing benomyl yielded more segregants. analysis of the segregants showed that the distribution of a. nidulans lin ... | 1979 | 372762 |
| deletion mapping of the niia niad gene region of aspergillus nidulans. | 1979 | 389740 | |
| recurrent mutation and selection for increased penicillin titre in aspergillus nidulans. | recurrent mutation and selection has been used to increase penicillin titre in two closely related strains of aspergillus nidulans. a selection programme was initiated from each of the two strains (programmes a and b) and continued through six cycles of mutation and selection. near-ultraviolet light in conjuction with 8-methoxypsoralen was employed as the sole mutagen throughout programme a and ethyl methanesulphonate as the sole mutagen throughout programme b. excluding the first cycle of a, wh ... | 1979 | 390092 |
| fine-structure mapping of the acetamidase structural gene and its controlling region in aspergillus nidulans. | a large number of amds mutants altered in acetamide utilization have been used to construct a fine-structure map of the amds locus. the mutagen diepoxyoctane generated most of the deletion strains used for mapping. a minimum of 14 sites within the amds gene were found. biochemical analysis of amds mutants defined the extent of the probable coding region. a new mutant, amd-205, which did not produce detectable inactive gene product, was found to be inseparable by recombination from the "up-promot ... | 1979 | 378765 |
| d-galactose requiring mutants in aspergillus nidulans lacking phosphoglucomutase. | 1979 | 383505 | |
| aspergillus nidulans as a test organism for assessing radio-induced chromosomal non-disjunction. | a genetically marked heterozygous diploid of aspergillus nidulans was synthesized and the feasibility of using this system for the simultaneous estimation of radio-induced mitotic crossing-over and non-disjunction has been investigated. in the case of the latter, serious experimental problems have been encountered. nevertheless, induction curves for non-disjunction with 15-mev electrons, 50-kvp x-rays, beta-particles and alpha-particles are presented showing an increase in non-disjunction with i ... | 1979 | 381904 |
| genetic control of transport loss during development of aspergillus nidulans. | 1979 | 378737 | |
| the regulation of hexokinase and phosphoglucomutase activity in aspergillus nidulans. | the levels of glucose-6-phosphate and 6-phosphogluconate dehydrogenase in wildtype cells of aspergillus nidulans varied with the carbon and nitrogen source. in general, hexokinase activity did not vary with carbon or nitrogen source. the ammonium derepressed mutant amra1 had only 50% of the wildtype level of hexokinase. phosphoglucomutase activity was low in wildtype cells grown with nitrate, but high in cells grown with ammonium when glucose was the carbon source. a non-inducible mutant, nira-1 ... | 1979 | 375022 |
| mode of action of the azasteroid antibiotic 15-aza-24 methylene-d-homocholesta-8,14-dien-3 beta-ol in ustilago maydis. | ustilago maydis sporidia treated with 0.1 mug of azasterol (15-aza-24-methylene-d-homocholesta-8,14-dien-3beta-ol) per ml appeared branched and vacuolated after 6 h of incubation. sporidial multiplication, dry weight increase, and synthesis of protein, deoxyribonucleic acid, and ribonucleic acid were only slightly or moderately inhibited during the initial 3 h of incubation. an increase of free fatty acids was observed in lipid extracts of treated sporidia after incubation for 3 h or more. ergos ... | 1979 | 383015 |
| molecular cloning of the 4.2 md ecori fragment of aspergillus nidulans mitochondrial dna. | the 4.2 md ecori fragment of aspergillus nidulans mitochondrial dna was cloned using the plasmid pbr 332 as vector and e. coli as host. hitherto unknown sequence of hindiii sites within this region of mitochondrial genome was established. | 1979 | 375024 |
| betaine-homocysteine methyltransferase in the fungus aspergillus nidulans. | 1979 | 393259 | |
| a model for hyphal growth and branching. | a mathematical model for hyphal growth and branching is described which relates cytological events within hyphae to mycelial growth kinetics. essentially the model quantifies qualitative theories of hyphal growth in which it is proposed that vesicles containing wall precursors and/or enzymes required for wall synthesis are generated at a constant rate throughout a mycelium and travel to the tips of hyphae where they fuse with the plasma membrane, liberating their contents into the wall and incre ... | 1979 | 379276 |
| product induction of purine hydroxylase ii in asperigillus nidulans. | by the use of a mutation, hxb-20, that eliminates purine hydroxylase ii activity but retains cross-reacting material and an ancillary nadh dehydrogenase activity, it has been established that 6-hydroxynicotinic acid rather than nicotinic acid, is the true inducer of purine hydroxylase ii. | 1979 | 384157 |
| do the tightly linked structural genes for nitrate and nitrite reductases in aspergillus nidulans form an operon? evidence from an insertional translocation which separates them. | previous work (rand and arst, 1977) led to the proposal that the nis-5 mutation results in a new low activity promoter for niia, the structural gene for nitrite reductase in aspergillus nidulans. expression of niia via this promoter differs from expression of niia via its normal promoter/initiator in that expression by the new promoter is not subject to nitrate induction or ammonium repression. nis-5 reduces but does not abolish niia expression mediated by the normal promoter/initiator. in this ... | 1979 | 384164 |
| rna polymerase from the fungus, aspergillus nidulans. large-scale purification of dna-dependent rna polymerase i (or a). | the dna-dependent rna polymerase i (or a) from the lower eukaryote aspergillus nidulans has been purified on a large scale to apparent homogeneity by homogenizing the fungal hyphae in liquid nitrogen, extraction of the enzyme at high salt concentration, precipitation of rna polymerase activity with polymin p (a polyethylene imine), elution of the rna polymerase from the polymin p precipitate, ammonium sulphate precipitation, molecular sieving on bio-gel a-1.5m, binding to ion-exchangers and dna- ... | 1979 | 380997 |
| [metabolic pathways of exogenous pyrimidines in aspergillus nidulans]. | studies on the susceptibility of the wild-type strain of aspergillus nidulans to 6-azauracil suggest that it synthesizes pyrimidines using a by-pass pathway which is induced with 6-azauracil. the effect of a series of pyrimidines on the toxic action of 5-fluorouracil, 5-fluorouidine and 5-fluorodeoxyuridine has been investigated. as the result of these studies, a scheme is proposed for the metabolism of some pyrimidine bases and nucleosides in aso. nidulans. | 1979 | 370519 |
| induced quantitative variation for penicillin titre in clonal populations of aspergillus nidulans. | the variation in penicillin titre within populations of cultures of aspergillus nidulans derived from untreated conidia and from conidia treated with ethyl methanesulphonate (ems), near-ultraviolet light in the presence of 8-methoxypsoralen (8mop) or n-methyl-n'-nitro-n-nitrosoguanidine (ntg), each at several dose levels, was determined. both mutagentreated and untreated populations showed a continuous distribution of pencillin titres. the population mean titre of the mutagenized populations was ... | 1979 | 372487 |
| cis-dominant regulatory mutations affecting the expression of gaba permease in aspergillus nidulans. | in aspergillus nidulans expression of the gaba gene, the probable structural gene for the gamma-amino-n-butyrate (gaba) permease, is controlled by induction, via the inta gene, ammonium repression, mediated by the area gene, and probably carbon catabolite repression. regulatory mutations, tightly linked to gaba, were selected by reverting an arear-2 strain on gaba as nitrogen source. these mutations, gabi-1, gabi-2, and gabi-3 result in increased gaba expression and are cis-dominant in their eff ... | 1979 | 375001 |
| studies on saprozoonosis. i. a survey on aspergillus species with special reference to occupational habits. | a comprehensive survey of aspergillus species has been carried out among different cattle and donkey handlers. a total of 300 pharyngeal swabs of different subjects including 100 control and 100 each from cattle and donkey handlers was investigated. all the subjects were found healthy. among the species of aspergillus, the number of a. flavus appeared higher followed by a. fumigatus, still lower number was encountered with other species like a. nidulans and a. glaucus. in order to establish the ... | 1979 | 429763 |
| toxic aspergilli from pistachio nuts. | pistachio nut samples taken during various stages of development from orchards in iran, showed that contamination with fungi occurred mainly during the later stages of nut development. members of the genera aspergillus and penicillium occurred most frequently. of the aspergilli, the species a. niger, a. flavus and a. fischeri var. spinosus occurred most frequently, followed by a. terreus, a. tamarii and a. nidulans. twenty-two isolates comprising 13 species were tested for toxicity to ducklings. ... | 1979 | 481560 |
| analysis of mitotic nondisjunction with aspergillus nidulans. | two methods to detect the induction of nondisjunction with a diploid stable strain of a. nidulans are described. the first method gives only qualitative results, while the second method is quantitative and dose-effect curves can be done. some physiological parameters affecting the induction of nondisjunction can also be studied, because either quiescent or germinating conidia can be treated with the drug under test. some agents inducing nondisjunction were also tested for the induction of point ... | 1979 | 387402 |
| genetic studies of nitrate assimilation in aspergillus nidulans. | 1979 | 389305 | |
| effect of egg-white & avidin on the growth of aspergillus nidulans & on its proteases & nadp-gdh. | 1979 | 387580 | |
| [uv-induced dna degradation in aspergillus nidulans cells]. | uv-induced dna degradation was studied in mycellial cells of aspergillus nidulans wild type and several uvs mutants. it was shown to be an enzymatic specific process which possibly reflects the excision of pyrimidine dimers from uv-damaged dna. inhibition of dna degradation by caffeine and 2,4-dinitrophenol shows the connection between degradation and repair of dna. two ways of dna degradation were found in a. nidulans cells, one of them being glucose dependent and the other--glucose independent ... | 1979 | 381100 |
| the effect of ultrasound on genetic instability in diploids of aspergillus nidulans. | ultrasonication at 20 khz and intensity of 59 w/cm2 of a diploid strain of aspergillus nidulans was ound to lead to a significant increase in haploidization of germinating conidiospores. in a preliminary study ultrasound was found not to have an effect on the rate of reverse mutation in conidiospore suspensions of auxotrophic mutants. | 1979 | 393595 |
| mms induction of different types of genetic damage in aspergillus nidulans: a comparative analysis in mutagenesis. | methyl methanesulphonate (mms) was used to test the induction of gene mutation, somatic crossing-over and mitotic non-disjunction in a. nidulans. gene mutation was tested by inducing mutants resistant to 8-azaguanine and revertants of methg1 in a haploid strain. somatic crossing-over was tested in heterozygous diploids, both with a selective method, i.e. inducing homozygosis to fpa resistance in a heterozygous fpa a1/+ strain, and with a non-selective method, i.e. identifying the frequencies of ... | 1979 | 388213 |
| protoplasts from aspergillus nidulans. | a very effective lytic enzyme system for massive micro/macro-scale production of protoplasts from the filamentous fungus aspergillus nidulans is described. a striking coincidence was observed between maximal lytic activity towards aspergillus mycelium and the presece of both chitinase and alpha-(1 leads to 3)-glucanase activities. the release of protoplasts was greatly enhanced by preincubating the mycelium with 2-deoxy-d-glucose. furthermore, protoplast formation was influenced by fungal age, c ... | 1979 | 399317 |
| phenotypes of double conidiation mutants of aspergillus nidulans. | a series of strains, doubly mutant at conidiation loci, have been made. the phenotypes of these strains reflected the epistasy of earlier blocking mutants over later ones and confirmed the order of gene sequence predicted from the phenotypes of single mutants. oligosporogenous mutants gave complex interactions, especially between brl and med mutants. these results indicated that (i) gene action overlapped in time, (ii) several parts of the conidial apparatus were interchangeable and (iii) nuclei ... | 1979 | 396353 |
| detection of 5-amino-4-imidazole-n-succinocarboxamide ribotide and hypoxanthine accumulation. a simple method for identification of some purine auxotrophs. | 1979 | 395166 | |
| allele specific and locus non-specific suppressors in aspergillus nidulans. | using n-methyl-n'-nitro-n-nitrosoguanidine, ultraviolet irradiation, ethyl methanesulphonate or 4-nitroquinoline-1-oxide mutagenesis and an enrichment method for the isolation of auxotrophs, 25 mutants with defects in the ada locus were obtained after screening 41,376 colonies. one of these, ada24, did not complement with any of the other ada mutants, had a very high reversion rate and had some other properties which usually characterize strains carrying nonsense mutations. all revertants of ada ... | 1979 | 393802 |
| mutational studies with diquat and paraquat in vitro. | diquat and paraquat were assayed in the following tests. (1) ames test in salmonella typhimurium (strains ta1535, ta1537, ta1538, ta98 and ta100) with and without rat-liver microsomal fractions. (2) resistance to 8-azaguanine in salmonella typhimurium (strain hisg46, ta92 and ta1535. (3) repair test in salmonella typhimurium (strains ta1538 and ta1978). (4) gene mutations in aspergillus nidulans: 8-ag resistance and methionine suppression (meth a1 locus). (5) lethal recessive damage in aspergill ... | 1979 | 390391 |
| allele specific, gene unspecific suppressors in aspergillus nidulans. | seven suppressor mutations have been isolated in aspergillus nidulans by coreversion of alleles in physiologically unrelated genes namely, alx, sb, alca, putative structural genes for allantoinase, sulphate permease and alcohol dehydrogenase respectively. the suppressors are allele specific, gene unspecific. those described map in four loci, suaa, b, c, d. suaa and suab are on linkage group iii, suac and suad on vii. suab111, suad103 and suad108 are semi-dominant in their suppression of alx4 and ... | 1979 | 395416 |
| evidence that p-fluorophenylalanine has a direct effect on tubulin in aspergillus nidulans. | three temperature-sensitive alleles of bena (bena11, 17 and 21) confer resistance to growth inhibition by p-fluorophenylalanine (fpa). fpa resistance cosegregates with the bena gene. two back-mutations in bena which cause loss of temperature sensitivity cause loss of fpa resistance, and two indirect suppressors of bena temperature sensitivity also cause fpa resistance to be lost. these results indicate that fpa resistance is an intrinsic property of the bena mutations. the intracellular phenylal ... | 1979 | 396355 |
| a new in vitro method for testing plant metabolism in mutagenicity studies. | a rapid method was proposed to detect whether a harmless agricultural chemical can be converted into a mutagenic one by plant metabolism. the method is based on the use of nicotiana alata cell cultures. results obtained with five pesticides (atrazine, dichlorvos, tetrachlorvinphos, kelevan, and maleic hydrazide) suggest that the proposed method simulates the metabolism of the whole plant. this procedure was also successfully applied to the genetic system of aspergillus nidulans. one pesticide, a ... | 1979 | 513148 |
| the preparation and partial characterization of antigenic fractions obtained from the mycelial walls of several aspergillus species. | extracts with immunological activity were prepared from aspergillus fumigatus, a. flavus, a. terreus, a. niger and a. nidulans. in each case crude mycelial wall was extracted with an aqueous solution of triton x-100 giving detergent-soluble material. further fractionation was achieved by removing the detergent from this solution; the resultant precipitate was removed by centrifugation, and the aqueous supernatant was used as a source of soluble antigens. the sensitivity of these preparations was ... | 1980 | 6157778 |
| physical map of aspergillus nidulans mitochondrial genes coding for ribosomal rna: an intervening sequence in the large rrna cistron. | a detailed map of the 32 kb mitochondrial genome of aspergillus nidulans has been obtained by locating the cleavage sites for restriction endonucleases pst i, bam h i, hha i, pvu ii, hpa ii and hae iii relative to the previously determined sites for eco r i, hind ii and hind iii. the genes for the small and large ribosomal subunit rnas were mapped by gel transfer hybridization of in vitro labelled rrna to restriction fragments of mitochondrial dna and its cloned eco r i fragment e3, and by elect ... | 1980 | 6246396 |
| introduction of transposon tn901 into a plasmid of anacystis nidulans: preparation for cloning in cyanobacteria. | we have used the tem beta-lactamase transposon tn901, located on escherichia coli plasmid pri46, to introduce in vivo a genetic marker into plasmid puh24, present in the cyanobacterial strain anacystis nidulans r-2. restriction enzyme analysis and heteroduplex studies of the 8.3 x 10(6)-dalton plasmids pch1-pch5, present in the ampicillin-resistant a. nidulans r-2 colonies obtained after transformation with pri46, demonstrated that these plasmids consist of the complete sequence of tn901 inserte ... | 1980 | 6246495 |
| conservation and rearrangement of mitochondrial structural gene sequences. | mitochondria contain the simplest dna molecules that are present in eukaryotes. mitochondrial dna (mtdna) is easily purified, and is an important model system for studying eukaryote gene structure and basic molecular processes. the protein sequences of mitochondrial gene products have been shown to be conserved from yeast to man, and there are definite similarities at the dna sequence level. in contrast, the overall organization of the mitochondrial genome is drastically different in these organ ... | 1980 | 6253835 |
| mitochondrial heterogeneity in aspergillus nidulans: in vivo protein biosynthetic activities of the mitochondrial populations. | two mitochondrial populations with cytochrome c oxidase activity, and densities of 1.07 and 1.08 g/ml have been separated by means of a dextran-sucrose gradient. the highest enzymatic specific activity appeared in the 1.07 g/ml band. the mitochondria assayed by their in vivo cycloheximide resistant leucine incorporation appeared at the 1.08 g/ml density band of the gradient. some amount of activity of cytochrome c oxidase, and leucine incorporation appeared at the bottom of the gradient. the cyt ... | 1980 | 6261314 |
| nuclear and mitochondrial suppression of a mitochondrially inherited cold-sensitive mutation in aspergillus nidulans. | partial suppressors of a mitochondrially inherited mutation, [cs-67], conferring cold-sensitivity at 20 degrees c were identified. these mapped at one mitochondrial and four unlinked nuclear loci. most suppressors partially restored the cytochrome aa3 deficiency of the cold-sensitive strain at 20 degrees c. strains carrying two or more suppressors and [cs-67] showed considerably impaired growth. this effect was temperature-dependent, being more severe at 37 degrees c, and was not expressed in th ... | 1980 | 6262432 |
| mitochondrial heterogeneity in aspergillus nidulans: evidence of in vivo transformation among different mitochondrial populations. | the distribution of mitochondria from aspergillus nidulans on a dextran-sucrose gradient resulted in the fractionation of three bands. the lightest band presented the highest respiratory and cytochrome c oxidase activities and was also the most active in the incorporation of tritiated glycerol. pulse-chase experiments with 3h-glycerol suggested that mitochondria from the light band was transformed to denser organelles as the organism grew. | 1980 | 6248928 |
| new leucine auxotrophs of aspergillus nidulans. | a series of aspergillus nidulans leucine auxotrophs were isolated after nitroquinoline-1-oxide treatment and analyzed. four complementation groups could be distinguished in addition to the previously known leua group. a putative mutant for isopropylmalate isomerase (leub) was mapped on chromosome i and found to be closely linked to leua. | 1980 | 6155050 |
| [the cyclic nucleotide system of aspergillus nidulans under the influence of methylbenzimidazol-2-ylcarbamate (mbc). i. a hypothetical mitosis model]. | the influence of methylbenzimidazol-2-yl carbamate (mbc) on the cyclic nucleotide system of germinating aspergillus nidulans conidia has been investigated throughout the cell cycle. the content in cyclic adenosine 3',5'-monophosphate (camp) and cyclic guanosine 3',5'-monophosphate (cgmp) is rapidly decreased in the course of conidia swelling and has been found not to be influenced by mbc. on the other hand, influence of mbc leads, in inhibited nuclear division, to a significant increase of the i ... | 1980 | 6106987 |
| the isolation and characterization of mutants defective in nitrate assimilation in neurospora crassa. | the isolation and characterization of mutants altered for nitrate assimilation in neurospora crassa is described. the mutants isolated can be subdivided into five classes on the basis of growth test that correspond to the growth patterns of existing mutants at six distinct loci. mutants with growth characteristics like those of nit-2, nit-3 and nit-6 are assigned to those loci on the basis of noncomplementation and lack of recombination. mutants that, from their growth patterns, appear to lack t ... | 1980 | 6449399 |
| [genetic control of pathways of pyrimidine metabolism in aspergillus nidulans. 1. isolation and genetic analysis of 6-azauracil resistant mutants]. | 147 mutants exhibiting the resistance to toxic effect of 6 azauracil have been isolated by nitrosoguanidine treatment from the wild strain of aspergillus nidulans. this mutants have been divided into 11 phenotypic groups according to its cross-resistance to 5-fluoroderivatives of uracil, uridine and deoxyuridine. the genetic analysis has shown that all mutations of resistance are of nuclear origin and dominant nature, and they are distributed on six loci of the chromosome viii. | 1980 | 6450084 |
| a mutation, adjacent to gene amds, defining the site of action of positive-control gene amdr in aspergillus nidulans. | in aspergillus nidulans the acetamidase enzyme is inducible by omega-amino acids, sources of acetyl-coenzyme a, and benzoate. the amdr (or inta) gene is a positive-control gene involved in omega-amino acid induction only. a cis-acting mutation amdi93 located in a complex controlling region adjacent to the acetamidase structural gene was found to abolish induction by omega-amino acids but not induction by other sources of induction. as predicted, this mutation was epistatic to constitutive amdr a ... | 1980 | 6769897 |
| air-borne fungi in the air of barcelona (spain). iii. the genus aspergillus link. | during a survey on the presence of species of the genus aspergillus in the air of the city of barcelona (spain), the following species were identified: aspergillus flavus link, a. niger van tieghem, a. fumigatus fresenius, a. clavatus desmazières, a. terreus thom, a. chevalieri (mang.) thom et church, a. niveus bloch, emend. thom et church, a. ochraceus wilhelm, a. versicolor (vuillemin) tiraboschi, and a. amstelodami (mang.) church et thom. | 1980 | 6770271 |
| bacteriophage infection interferes with guanosine 3'-diphosphate-5'-diphosphate accumulation induced by energy and nitrogen starvation in the cyanobacterium anacystis nidulans. | anacystis nidulans accumulates large amounts of guanosine 3'-diphosphate-5'-diphosphate (ppgpp) upon nutritional or energy starvation induced by light-to-dark shift, treatment with carbonylcyanide-m-chlorophenylhydrazone (an uncoupler), or treatment with l-methionine-dl-sulfoximine (an inducer of nitrogen starvation). in contrast to healthy a. nidulans cells, those infected by as-1 cyanophage do not respond with ppgpp accumulation when starved after about one-third of the complete infection cyc ... | 1980 | 6777368 |
| [comparative study of the oxygen reduction in photosystem ii of the cyanobacteria, anacystis nidulans and anabaena variabilis]. | oxygen reduction in the photosystem ii (ps ii) of thylakoid membranes from the cyanobacteria anacystis nidulans and anabaena variabilis was studied in the system simo + dcmu in whose presence competitive electron transport to simo and o2 in possible. the reagents of the mehler reaction were used; these reagents activate oxygen uptake by interacting with the reduced forms of oxygen (malonate and oxalate with o2; glyoxylate and catalase + ethanol with h2o2). the use of the reagents as shown that t ... | 1980 | 6782430 |
| international commission for protection against environmental mutagens and carcinogens. icpemc publication no. 5: an evaluation of the genetic toxicity of dichlorvos. | 1980 | 6782471 |