PMID(sorted ascending)
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 ...1978363427
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 ...1978363429
[isolation and genetic study of aspergillus nidulans mutants defective in pyrimidine biosynthesis].8 uridine-requiring pyr mutants were isolated from aspergillus nidulans under nitrosoguanidine treatment. all the mutants are capable to grow on the medium containing 20 mkg/ml of uridine or cytidine, or 100 mkg/ml of uracil, and they do not utilize thymidine, thymine, cytosine and deoxyuridine. their ability to grow in the presence of orotic acid demonstrates that the pyrimidine synthesis in all the mutants is blocked at stages preceding the conversion of orotic acid into orotidine monophosphat ...1978363504
a hydroxamic acid from aspergillus nidulans with antibiotic activity against proteus iron-complexing antibiotic with a narrow spectrum of biological activity was produced by several strains of aspergillus nidulans when grown in a low-iron, chemically defined medium. its chemical and biological properties closely resembled those of desferritriacetylfusigen, a metabolite of several other aspergilli and penicillia.1978363670
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.1978364902
[presence of sexual forms (cleistothecia and hülle cells) in a case of human maxillary sinus aspergillosis caused by aspergillus nidulans in association with aspergillus fumigatus].the authors observed, in a biopsic sample from a human maxillary sinus, the coexistence, in parasitic stages, of two different aspergillus species: a. fumigatus and a. nidulans. after having described the morphologies of each species, in sections on slides, and particularly those of cleistothecia and hülle-cells for the second, they draw attention to the three interests of such an observation: -- rarety of observing aspergillus nidulans in a parasitic stage, in spite of its particular thermotole ...1978366429
aspects of the molecular biology of lipoamide dehydrogenase. 1978367117
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 ...1978368568
lactam utilisation in aspergillus nidulans: evidence for a fourth gene under the control of the integrator gene inta.mutations in the lama gene of aspergillus nidulans prevent the conversion of exogenous 2-pyrrolidone (gamma-butyrolactam) to gamma-amino-n-butyrate (gaba) and also prevent the (probably analogous) utilisation of 2-piperidone (sigma-valerolactam). the lama gene, in linkage group viii, probably specifies a lactamase but a rôle in lactam uptake cannot be ruled out. lama is probably under the control of the positive acting regulatory gene inta, which can integrate its expression with the expression ...1978368580
regulatory properties of pyruvate carboxylase from aspergillus nidulans: evidence for the presence of a masked activator site [proceedings]. 1978369914
[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 ...1978370508
[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.1979370519
virulence genetics of aspergillus nidulans eidam: a review.studies of the influence of genotypic alterations on the murine virulence of aspergillus nidulans eidam are reviewed to emphasize the potential of this fungus for genetic studies of virulence.1978370604
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 ...1979372487
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 ...1979372762
cis-dominant regulatory mutations affecting the expression of gaba permease in aspergillus 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 ...1979375001
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 ...1979375022
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.1979375024
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 ...1979375074
characterization of a new choline locus in aspergillus nidulans and its significance for choline metabolism. 1978376401
identification of a gene for alpha-tubulin in aspergillus nidulans. 1979378391
genetic control of transport loss during development of aspergillus nidulans. 1979378737
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 ...1979378765
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 ...1979379276
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- ...1979380997
[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 ...1979381100
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 ...1979381904
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 ...1979383015
d-galactose requiring mutants in aspergillus nidulans lacking phosphoglucomutase. 1979383505
product induction of purine hydroxylase ii in asperigillus 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.1979384157
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 ...1979384164
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 ...1979387402
effect of egg-white & avidin on the growth of aspergillus nidulans & on its proteases & nadp-gdh. 1979387580
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 ...1979388213
genetic studies of nitrate assimilation in aspergillus nidulans. 1979389305
deletion mapping of the niia niad gene region of aspergillus nidulans. 1979389740
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 ...1979390092
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 ...1979390391
betaine-homocysteine methyltransferase in the fungus aspergillus nidulans. 1979393259
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.1979393595
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 ...1979393802
detection of 5-amino-4-imidazole-n-succinocarboxamide ribotide and hypoxanthine accumulation. a simple method for identification of some purine auxotrophs. 1979395166
allele specific, gene unspecific suppressors in aspergillus 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 ...1979395416
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 ...1979396353
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 ...1979396355
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 ...1979399317
growth, glucose metabolism and melanin formation in biotin-deficient aspergillus nidulans.biotin deficiency resulted in an increased growth rate of aspergillus nidulans. the activities of hexokinase and aldolase were not much changed during the growth cycle, but activities of glucose-6-phosphate dehydrogenase and nadp-linked glutamate dehydrogenase increased significantly during the exponential phase. this change was remarkable during biotin deficiency. in contrast to the higher growth rate and respiration rate during biotin deficiency the activities of nad(p)h oxidoreductases were l ...1977402307
glucan common to the microcyst walls of cyst-forming bacteria.chemical analysis indicated that d-glucose is tha major neutral monosaccharide present in the microcysts of a range of gram-negative bacteria. varying amounts of other neutral sugars were found. the glucose was mainly present as a glucan that could be extracted from microcysts of representative strains with alkali or mild acid treatment. the glucan could be identified as an alpha-1,3-linked polymer on the basis of (i) periodate resistance of the extracted polymer and the material present in micr ...1977402353
temperature dependence on the delayed fluorescence of chlorophyll a in blue-green algae.1. the delayed fluorescence of chlorophyll a was measured with a phosphoroscope by changing the temperature in a range of room temperatures in intact cells of blue-green algae, anacystis nidulans, two strains of anabaena variabilis and plectonema boryanum, and other kinds of algae, cyanidium caldarium and chlorella pyrenoidosa. the induction of delayed fluorescence remarkably depended on the temperature of measurment. nevertheless, the induction pattern was characterized by three levels of inten ...1977403943
interference of cellular ferric ions with dna extraction and the application to methods of dna determination. 1977405886
photosynthetic activity of diimidoester-modified cells, permeaplasts, and cell-free membrane fragments of the blue-green alga anacystis nidulans.on treating the blue green alga anacystis nidulans with dimethylsuberimidate up to 70% of the free nh2 of the photosynthetic membrane is amidinated, and presumably inter- and intramolecular cross-links are established in the membrane proteins. amidination destroys the ability of a. nidulans to photoreduce hco3(-) but leaves the photochemical activities of photosystems ii and i nearly intact. with added electron acceptors, photosynthetic o2 evolution can be demonstrated both with permeable cells ...1977409432
occurrence of a major protein associated with fruiting body development in neurospora and related ascomycetes.electrophoretic and immunological analysis of fruiting body (perithecial) extracts demonstrates the occurrence of a major phase-specific perithecial protein in all neurospora species and in the closely related gelasinospora cerealis and sordariafimicola. the perithecial proteins from these different species fall into a number of groups with different electrophoretic mobilities. they appear to be immunologically closely related but not identical to one another even within the same genus, with onl ...1977410027
adsorption of cyanophage as-1 to unicellular cyanobacteria and isolation of receptor material from anacystis nidulans.cells of unicellular cyanobacteria of typological group ia, containing approximately 50 mol% guanine + cytosine (g+c) in their dna (r. y. stanier, r. kunisawa, m. mandel, and g. cohen-bazire, bacteriol. rev. 35:171-205, 1971), were susceptible to infection by the cyanophage as-1. cyanobacteria of the same typological group, containing approximately 65 mol% g+c in their dna, did not adsorb the cyanophage as-1 or adsorbed it at a low rate. as-1 was not propagated by any of the investigated strains ...1978413935
culture and antigen variants of aspergillus. 1978416063
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 ...1979429763
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. ...1979481560
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 ...1979513148
[the effectiveness of an (aspergillus) differential medium in the course of the mycological examination of foods].the effectiveness of aspergillus differential medium (adm) for the identification of aspergillus strains was tested. the bright yellow-orange pigment was produced by 205 (88,7%) of 231 strains and resp. 97 (61,3%) of 158 strains, which during routine mycologic diagnostic as a.flavus and a.oryzae, respectively. strains of the groups a.clavatus (76), a.glacus (100), a.fumigatus-(9), a.niger-(6), a.candidus-(3), a.wentii-(1), a.versicolor (23), a.nidulans (6), a.ustus (1) and a.terreus (1) gave neg ...1978706813
three-marker extranuclear mitochondrial crosses in aspergillus nidulans.two- and three-point extranuclear crosses have been carried out via heterokaryons involving the three extranuclear mitochondrial markers of aspergillus nidulans: (olia1), (cs67) and (cama112). all three markers appear to be located on a single functional mitochondrial genome. recombination between all three pairs of extranuclear markers appears to be equally frequent, suggesting a lack of genetic linkage. an important feature of these results is the variable and often marked non-equality of freq ...1975765725
transmission and recombination of extranuclear genes during sexual crosses in aspergillus nidulans.three extranuclear mitochondrial mutations in aspergillus nidulans, (olia1), (cama1) and (cs67), were used as markers in sexual crosses to provide information on the frequencies of transmission and recombination of the mitochondrial genome. any individual perithecium contained ascospores of only one extranuclear genotype. using mono-, bi- and trifactorial crosses it was found that all three markers could be recovered from the progeny, although the transmission frequencies were different for each ...1975765748
the effects of temperature on genetic instability in aspergillus nidulans.previous work has shown that strains of aspergillus nidulans with a chromosome segment in duplicate (one in normal position, one translocated to another chromosome) are unstable. deletions occur from either duplicate segment. the present work has shown that most deletions occur from the translocated duplicate segment. furthermore, it has been found that the overall frequency of deletions from a duplication is dependent upon the temperature of growth. the overall frequency of deletions from a chr ...1976765807
hyper-repressible operator-type mutant in sulphate permease gene of aspergillus nidulans. 1976765839
a temperature-sensitive mutant of aspergillus nidulans reversibly blocked in nuclear division. 1976767122
altered instability due to genetic changes in a duplication strain of aspergillus nidulans. 1975767217
role of organic phosphates in the formation of phosphatases in aspergillus nidulans. 1975767255
initial characterization of aspergillus nidulans mutants blocked in the nuclear replication cycle.several hundred temperature-sensitive mutants of aspergillus nidulans were screened for ability of their conidia to produce germ tubes at the nonpermissive temperature while still remaining with the original single conidial nucleus.1976770457
determination of the execution points of mutations in the nuclear replication cycle of aspergillus nidulans.cultures of nuclear replication cycle mutants of aspergillus nidulans were transferred to the nonpermissive temperature, and the fraction of nuclei still able to reach mitosis was determined. for the determinations, benomyl [methyl-1(butylcarbomoyl)benzimidazolecarbamate] was added to trap nuclei in mitosis, and these were detected by staining with aceto-orcein. the assumptions and controls required to relate the experimentally determined fractions to the points where a mutation blocks the nucle ...1976770458
tubulin-like protein from aspergillus nidulans. 1976773373
acquired resistance to benzimidazole derivatives. 1975773644
mitochondrial dna from aspergillus nidulans. 1975773682
subcellular mislocation of cysteine synthase in a cysteine auxotroph of aspergillus nidulans. 1975773683
ornithine decarboxylase activity in germinating conidia of aspergillus nidulans. 1975773695
mitotic crossing over and nondisjunction in translocation heterozygotes of analyze mitotic recombination in translocation heterozygotes of a. nidulans two sets of well-marked diploids were constructed, homo- or heterozygous for the reciprocal translocations t1 (il;viir) or t2 (il;viir) and heterozygous for selective markers on il. it was found that from all translocation heterozygotes some of the expected mitotic crossover types could be selected. such crossovers are monosomic for one translocated segment and trisomic for the other and recovery depends on the relati ...1976773747
mitotic mutants of aspergillus nidulans. 1975773766
cholorate toxicity in aspergillus nidulans: the selection and characterisation of chlorate resistant mutants.mutation in at least ten genes can result in chlorate reistance in aspergillus nidulans. mutation in seven of these genes also results in the inability to use nitrate as nitrogen source. the various classes of resistant mutant obtained occur in different proportions, depending on whether or not a mutagenic treatment is employed, and also on which nitrogen source is used for selection. the prinicipal effect of mutagen arises because mutations in the niad gene, the nitrate reductase structural gen ...1976773908
well-marked strains of aspergillus for tests of environmental mutagens: identification of induced mitotic recombination and mutation. 1976775325
mutants of aspergillus nidulans lacking pyruvate kinase. 1976776698
the isolation of nuclei from the filamentous fungus aspergillus nidulans.a method has been developed for isolating nuclei from the filamentous fungus aspergillus nidulans. in this procedure, the mycelia from 14 to 16 h spore-derived cultures of a. nidulans nri, a stable diploid strain, were frozen with liquid nitrogen and homogenized in a waring blender. after homogenization, the mycelia were warmed to 4 degrees c and the nuclei were purified from the homogenate by differential centrifugation followed by sedimentation through 2.1 m-sucrose. the final nuclear yield wa ...1976778331
effect of glucose, ammonium and media maintenance on the time of conidiophore initiation by surface colonies of aspergillus nidulans. 1976778332
agar as a carbon source and its effect on the utilization of other carbon sources by acetate non-utilizing (acu) mutants of aspergillus nidulans. 1976778333
integrator gene in aspergillus nidulans. 1976778641
enhancement of tissue invasion in murine aspergillosis by systemic administration of suspensions of killed corynebacterium parvum.the effect of killed corynebacterium parvum vaccine on the course of murine aspergillosis is described. a grid-counting technique was employed to quantitate tissue invasion by aspergillus nidulans in the brain, heart, and kidneys (the target organs) of normal mice and of mice treated systemically with killed c. parvum vaccine. simultaneous treatment of mice with c. parvum and a. nidulans significantly increased the mortality rate, in contrast to treatment of mice with c. parvum prior to or follo ...1976779492
proceedings: influence of microwaves on genetical processes of aspergillius nidulans. 1976781259
partial purification of methionine binding protein from aspergillus nidulans by affinity chromatography. 1976782531
nucleosome structure in aspergillus nidulans.the structure of chromatin from aspergillus nidulans was studied using micrococcal nuclease and dnaase i. limited digestion with micrococcal nuclease revealed a nucleosomal repeat of 154 base pairs for aspergillus and 198 base pairs for rat liver. with more extensive digestion, both types of chromatin gave a similar quasi-limit product with a prominent fragment at 140 base pairs. the similarity of the two limit digests suggests that the structure of the 140 base pair nucleosome core is conserved ...1976782724
[thermosensitive lethal mutants in aspergillus nidulans]. 1975785156
chloral hydrate induced haploidization in aspergillus nidulans.this is the first report of induction of haploidization in aspergillus nidulans by chloral hydrate, which is an efficient polyploidizing agent for higher plants and a psychotropic drug for man. a new procedure has been described to isolate haploids from diploids with a very high frequency, as compared to p-fluorophenylalanine, which is generally used for this purpose.1976786720
fungal infections after renal transplantation.fungal infections occurred in 3 of 22 renal transplants (13.6%). two patients developed rhinocerebral phycomycosis, and rhizopus arrhizus was isolated from cultures of the nasal conchae. both patients were treated with systemic amphotericin b. three-and-a-half months after transplantation the third patient developed an acute ureteral obstruction secondary to infection with aspergillus nidulans; this necessitated removal of the graft. there was no immediate mortality associated with these fungal ...1976786944
the genetic instability and mutagenic interaction of chromosomal duplications present together in haploid strains of aspergillus nidulans.previous work has shown that strains of aspergillus nidulans with a chromosome segment in duplicate (one in normal position, one translocated to another chromosome) are unstable. deletions occur from either duplicate segment. the present work has shown that when a chromosome i duplication and a chromosome iii duplication are together in a haploid, deletions from the intact iii duplication generally precede deletions from particular sections of the i duplication. furthermore, the iii duplication ...1976787776
the use of analytical electron microscopy in the study of three species of aspergillaceae.the combination of electron beam scanning and x-ray detection allows to use the scanning electron probe microanalyzer as a sensitive microscope to elemental constitution. this made it possible to investigate three species of the aspergillus nidulans group: a. nidulans, a. unguis, a. variecolor. qualitative differences were found between the three species. the application of microanalysis is regarded as a useful addition to more conventional methods used in histochemical studies. the advantages o ...1975787898
polyamine and ornithine metabolism during the germination of conidia of aspergillus nidulans.1. the activities of ornithine decarboxylase, s-adenosylmethionine decarboxylase and ornithine-2-oxoglutarate aminotransferase were studied during the first 24 h of conidial germination in aspergillus nidulans. 2. increases (over 100-fold) in the activities of ornithine decarboxylase and s-adenosylmethionine decarboxylase occurred during the emergence of the germ-tube and before the doubling of dna and this was followed by a sharp fall in the activities of both enzymes by 16h. 3. the increase in ...1976791270
[dna degradation induced by radiation in aspergillus nidulans]. 1976791383
phosphorus uptake in biotin deficient aspergillus nidulans: an evidence for the involvement of binding protein in this process. 1976791857
relationship of the genetic determination of impaired penicillin production in naturally occurring strains to that in induced mutants of aspergillus nidulans. 1976792389
estimation of the generation time and peripheral growth zone of aspergillus nidulans and alternaria solani hyphae from radial growth rates and ranges in apical cell length. 1976792392
purification of a deoxyribonuclease from aspergillus nidulans. 1976793906
mitosis, septation, branching and the duplication cycle in aspergillus nidulans.mitosis, septation and branching were studied in undifferentiated mycelia and leading hyphae of aspergillus nidulans, a mould which forms incomplete septa. after spore germination, nuclei divided synchronously until germ-tube hyphae contained 8 or 16 nuclei; mitosis occurred when the volume of cytoplasm per haploid nucleus was about 60 mum3. intercompartment development was not synchronized, consequently mitosis in the mycelium as a whole eventually became asynchronous. during the stage of async ...1976796408
formation of nadph-nitrate reductase activity in vitro from aspergillus nidulans niad and cnx mutants.mutants of a. nidulans at several loci lack detectable nadph-nitrate reductase activity. these loci include niad, the structural gene for the nitrate reductase polypeptide, and five other loci termed cnxabc, e, f, g and h which are presumed to be involved in the formation of a molybdenum-containing component (mcc) necessary for nitrate reductase activity. when forzen mycelia from a. nidulans deletion mutant niad26 were homogenized in a ten broeck homogenizer together with frozen mycelia from eit ...1976796678
panel discussion on submammalian systems. 1976796705
synthesis of polyamines in the germinating conidia of aspergillus nidulans. 1976798705
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