Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| a hybrid plasmid is a stable cloning vector for the cyanobacterium anacystis nidulans r2. | anacystis nidulans r2 is a highly transformable strain which is suitable as a recipient for molecular cloning in cyanobacteria. in an effort to produce an appropriate cloning vector, we constructed a hybrid plasmid molecule, psg111, which contained pbr328 from escherichia coli and the native puh24 plasmid of a. nidulans. psg111 replicated in and conferred ampicillin and chloramphenicol resistance to both hosts. it contained unique sites for the restriction enzymes ecori, sali, sphi, and xhoi, wh ... | 1983 | 6309751 |
| shuttle cloning vectors for the cyanobacterium anacystis nidulans. | hybrid plasmids capable of acting as shuttle cloning vectors in escherichia coli and the cyanobacterium anacystis nidulans r2 were constructed by in vitro ligation. dna from the small endogenous plasmid of a. nidulans was combined with two e. coli vectors, pbr325 and pdpl13, to create vectors containing either two selectable antibiotic resistance markers or a single marker linked to a flexible multisite polylinker. nonessential dna was deleted from the polylinker containing plasmid pplan b2 to p ... | 1983 | 6311795 |
| a host-vector system for gene cloning in the cyanobacterium anacystis nidulans r2. | we describe the construction of a series of vectors suitable for gene cloning in the cyanobacterium anacystis nidulans r2. from the indigenous plasmid puh24, derivatives were constructed with streptomycin as the selective marker; one of these plasmids was used to construct puc303, a shuttle vector capable of replication in a. nidulans r2 as well as in escherichia coli k12. it has two markers, streptomycin and chloramphenicol resistance, and three unique restriction sites. instability of recombin ... | 1983 | 6314409 |
| distinction between cofactor-dependent and -independent phosphoglycerate mutases by chromatography on cibacron blue-sepharose. | the binding of phosphoglycerate mutases from a variety of sources to cibacron blue-sepharose has been examined. those enzymes which are dependent on 2,3-bisphosphoglycerate (bpg) for activity bind to the immobilized dye and can be eluted by bpg. those enzymes which are independent of bpg do not bind to the immobilized dye. the possible structural significance of this distinction is discussed. | 1983 | 6315103 |
| sequence homology and structural similarity between cytochrome b of mitochondrial complex iii and the chloroplast b6-f complex: position of the cytochrome b hemes in the membrane. | the amino acid sequences of cytochrome b of complex iii from five different mitochondrial sources (human, bovine, mouse, yeast, and aspergillus nidulans) and the chloroplast cytochrome b6 from spinach show a high degree of homology. calculation of the distribution of hydrophobic residues with a "hydropathy" function that is conserved in this family of proteins implies that the membrane-folding pattern of the 42-kilodalton (kda) mitochondrial cytochromes involves 8-9 membrane-spanning domains. th ... | 1984 | 6322162 |
| optical and electron paramagnetic resonance spectroscopic studies on purine hydroxylase ii from aspergillus nidulans. | purine hydroxylase ii from aspergillus nidulans contains a molybdenum cofactor very similar to that found in a number of other molybdenum-containing hydroxylases. (a. nidulans contains two purine hydroxylases, i and ii, related to each other by possession of a common cofactor and overlapping substrate specificity.) addition of reducing substrates effects bleaching of the visible absorption spectrum of the enzyme, the decrease in absorbance at 450 nm being linearly proportional to that at 550 nm. ... | 1984 | 6322698 |
| amino acid sequence of a new mitochondrially synthesized proteolipid of the atp synthase of saccharomyces cerevisiae. | the purification and the amino acid sequence of a proteolipid translated on ribosomes in yeast mitochondria is reported. this protein, which is a subunit of the atp synthase, was purified by extraction with chloroform/methanol (2/1) and subsequent chromatography on phosphocellulose and reverse phase h.p.l.c. a mol. wt. of 5500 was estimated by chromatography on bio-gel p-30 in 80% formic acid. the complete amino acid sequence of this protein was determined by automated solid phase edman degradat ... | 1984 | 6323165 |
| developmental regulation of the aspergillus nidulans trpc gene. | we have cloned the trifunctional trpc gene from aspergillus nidulans by hybrid phage lambda complementation of an escherichia coli trpc mutant lacking phosphoribosylanthranilate isomerase activity. four different phages sharing a 4.3-kilobase region were obtained. plasmid subclones containing this region also complemented the e. coli trpc mutant. we determined that a 1.8-kilobase dna fragment was minimally required for complementation. the fragment hybridized with two poly(a)+ rnas, 3.0 and 3.2 ... | 1983 | 6324178 |
| transformation of aspergillus nidulans by using a trpc plasmid. | we constructed a chimeric plasmid carrying a complete copy of the trifunctional trpc gene from the ascomycete fungus aspergillus nidulans. this plasmid, designated phy201, replicates in escherichia coli, where it confers resistance to ampicillin and chloramphenicol and complements trpc mutants lacking phosphoribosylanthranilate isomerase activity. we used phy201 to transform an a. nidulans trpc- strain to trpc+ at frequencies of greater than 20 stable transformants per microgram of dna. southern ... | 1984 | 6324193 |
| identification of the probable coding region for exon 2 of cytochrome oxidase polypeptide i from aspergillus nidulans mitochondrion. | hypothetical protein urfe of aspergillus nidulans mitochondrion is homologous with the amino end of cytochrome oxidase (ec 1.9.3.1) polypeptide i. unidentified reading frame urfe does not contain a suitable initiation codon and codes for a protein with a length of only 91 residues, corresponding to about 20% of cytochrome oxidase polypeptide i. it is proposed that this region codes for the second exon of the cox 1 gene of aspergillus mitochondrion. possible candidates for the 2- to 3-residue ami ... | 1984 | 6324773 |
| cloning of nitrate reductase genes from the cyanobacterium anacystis nidulans. | anacystis nidulans, a non-nitrogen-fixing cyanobacterium, can fulfill its nitrogen requirement by the assimilation of nitrate. the first step in the pathway, the reduction of nitrate to nitrite, is catalyzed by the molybdo-protein nitrate reductase. in this study, newly developed techniques for gene cloning in a. nidulans r2 were used for the isolation of two genes involved in nitrate reduction. one gene was cloned by complementation of the corresponding mutant; the other gene was picked up from ... | 1984 | 6330039 |
| a mutation in aspergillus nidulans that blocks the transition from interphase to prophase. | in order to develop a method for obtaining mitotic synchrony in aspergillus nidulans, we have characterized previously isolated heat-sensitive nim mutations that block the nuclear division cycle in interphase at restrictive temperature. after 3.5 h at restrictive temperature the mitotic index of a strain carrying one of these mutations, nima5, was 0, but when this strain was subsequently shifted from restrictive to permissive temperature the mitotic index increased rapidly, reaching a maximum of ... | 1983 | 6339527 |
| detection of a proteinase inhibitor in aspergillus nidulans. | the activity of proteinases in mycelial extracts of aspergillus nidulans increased during storage. the rate of activation increased with temperature. three separate proteinase activities, differing in their electrophoretic mobilities on polyacrylamide gels, were readily detected at ph 6.5. inhibitory activity, effective against all three proteinase activities, was also detected in fractions prepared from fresh mycelial extracts. the inhibitory factor(s) were heat-stable and non-dialysable. the i ... | 1983 | 6339674 |
| dna duplication has resulted in transfer of an amino-terminal peptide between two mitochondrial proteins. | the mitochondrial genome of the ascomycete aspergillus nidulans possesses at least nine unidentified reading frames (urfs). two of these are particularly interesting in that the amino acid sequences of the derived translation products are very similar in the n-terminal regions. the first 36 residues of the urfx gene product are repeated at the start of a second reading frame, urfa3, with only six mismatches. despite this similarity in their amino-termini, the latter parts of urfx and urfa3 are c ... | 1983 | 6339955 |
| [lethal and mutagenic action of solar radiation on model microbiological test systems]. | lethal, mutagenic and recombonogenic action of the solar radiation on the model microorganisms--phage t4, bacteria escherichia coli and ascomycet aspergillus nidulans--has been studied. a considerable lethal effect of the solar radiation on phage t4 and e. coli was found. an increasing of mutation frequency in e. coli and a. nidulans by sunlight was also revealed. recombinogenic action of solar radiation has been demonstrated in the experiments with diploid a. nidulans strains. it was shown that ... | 1983 | 6340743 |
| diagnosis of nonsense mutations in aspergillus nidulans. | three genotypically suppressible alleles, a1x4, alca125, and niad500, are phenotypically suppressed by aminoglycoside antibiotics. unsuppressible alleles at these loci are unaffected as are known missense mutations at the ya and gdha loci. this is consistent with the premise that the suppressible mutations are nonsense and that this highly-allele-specific phenotypic suppression can be used to distinguish nonsense from missense mutations of aspergillus nidulans. paromomycin and tobramycin are rec ... | 1983 | 6340750 |
| laccase localized in hulle cells and cleistothecial primordia of aspergillus nidulans. | several species of the genus aspergillus form sexual spores within minute (approximately 0.2 mm) spherical shells (cleisthothecia) which are woven from specialized hyphae. aspergillus nidulans cleistothecia are uniquely characterized by their dark red coloration and an envelope of thick-walled globose cells (hulle cells). by use of a new chromogenic substrate, we have shown that the constitutent hyphae of young cleistothecia and the hulle cells which surround the cleistothecia of a. nidulans exh ... | 1983 | 6341366 |
| conditionally lethal tubulin mutations of aspergillus nidulans. | conditionally lethal tubulin mutants are becoming an important tool for studying microtubule structure and function. in the filamentous fungus aspergillus nidulans it has been possible to isolate heat-sensitive beta-tubulin mutations by isolating mutants resistant to the anti-microtubule agent benomyl and screening these mutants for heat sensitivity. it has also been possible to isolate alpha-tubulin mutations, new beta-tubulin mutations and mutations in other genes whose products are likely to ... | 1983 | 6341617 |
| short-cycle conidiation in aspergillus nidulans influence of glucose concentration and acetate or citrate supply. | this paper considers the effects of the reduction of the glucose concentration in the medium or of its substitution by intermediates closely related to the tca cycle, namely acetate and citrate, on the balance between conidiation and mycelial growth in aspergillus nidulans. it is shown that in conditions of extreme depletion of glucose in the medium, or in the presence of citrate as the only source of organic carbon, the reduction of mycelial growth proceeds to such as extent that conidiophores ... | 1983 | 6341779 |
| the sub-cellular localisation of pyruvate carboxylase and of some other enzymes in aspergillus nidulans. | the sub-cellular localisation of enzymes has been defined by latency analysis, and fractionation by differential centrifugation, in cell-free extracts prepared from the mycelium of aspergillus nidulans by growth in the presence of 2-deoxyglucose followed by treatment with a mixture of beta-glucuronidase, sulphatase and beta-glucanase and exposure to n2 cavitation at 5.2 pma. in such extracts pyruvate carboxylase and nad-dependent and nadp-dependent glutamate dehydrogenases are exclusively locali ... | 1983 | 6345155 |
| nitrite toxicity in aspergillus nidulans: a new locus in a proa1 pabaa6 ya2 strain. | 1983 | 6345269 | |
| mutagenicity screening with fungal systems. | several fungal species have been used for mutagenicity screening: aspergillus nidulans, saccharomyces cerevisiae, and neurospora crassa. the eukaryotic nature of these organisms with typical chromosomes in a nucleus and their mitotic and meiotic mode of nuclear division have been the basis for the development of test systems that cover the full spectrum of genetic changes typical for eukaryotes. it is possible to detect simple point mutations and also grosser structural chromosomal alterations. ... | 1983 | 6349475 |
| properties of deoxyribonuclease 4 from aspergillus nidulans. | deoxyribonuclease 4 from aspergillus nidulans was purified to over 70% homogeneity. it contains a polypeptide of mr about 30000, and behaves as a dimer, but with some evidence of dissociation on gel filtration and ultracentrifugation. the ph optimum is 7-9. activity is supported by metal ions in the order (mn2+ + ca2+) greater than mn2+ approximately equal to (mg2+ + ca2+) much greater than mg2+. mn2+ is optimal at 10-20 mm. dnaase 4 strongly prefers native dna, for which the km is about 0.5 mm, ... | 1983 | 6349692 |
| nitrate uptake in aspergillus nidulans and involvement of the third gene of the nitrate assimilation gene cluster. | in aspergillus nidulans, chlorate strongly inhibited net nitrate uptake, a process separate and distinct from, but dependent upon, the nitrate reductase reaction. uptake was inhibited by uncouplers, indicating that a proton gradient across the plasma membrane is required. cyanide, azide, and n-ethylmaleimide were also potent inhibitors of uptake, but these compounds also inhibited nitrate reductase. the net uptake kinetics were problematic, presumably due to the presence of more than one uptake ... | 1983 | 6350263 |
| mitochondrial transfer rna genes from fungi (aspergillus nidulans) and plants (lupinus luteus) are transcribed in xenopus laevis oocyte nuclei. | three plasmids containing aspergillus nidulans mitochondrial transfer rna genes were microinjected into the nucleus of xenopus laevis oocytes. plasmids that contained a single trnacys gene or two trna genes (arg and asn) yielded trna-sized transcripts. plasmids containing cloned lupinus mitochondrial trna genes were also transcribed and processed in x. laevis nuclei. | 1983 | 6350603 |
| kinetics of the nuclear division cycle of aspergillus nidulans. | we have analyzed the cell cycle kinetics of aspergillus nidulans by using the dna synthesis inhibitor hydroxyurea (hu) and a temperature-sensitive cell cycle mutant nimt that blocks in g2. hu rapidly inhibits dna synthesis (s), and as a consequence progression beyond s to mitosis (m) is blocked. upon removal of hu the inhibition is rapidly reversible. conidia (asexual spores) of nimt were germinated at restrictive temperature to synchronize germlings in g2 and then downshifted to permissive temp ... | 1983 | 6352675 |
| isolation of genomic clones containing the amds gene of aspergillus nidulans and their use in the analysis of structural and regulatory mutations. | previous analysis of the amds gene of aspergillus nidulans has identified multiple regulatory circuits mediated by trans-acting regulatory genes, cis-acting mutations have been identified and shown to specifically affect individual regulatory circuits. fine-structure genetic mapping of the amds regions showed that these cis-acting mutations occur in a complex controlling region adjacent to the amds structural gene. the amds gene was cloned by differential hybridization, using cdna probes derived ... | 1983 | 6353203 |
| purification and properties of two neutral proteinases from aspergillus nidulans. | two proteinases have been purified from mycelial extracts of aspergillus nidulans. both enzymes have ph optima between 6.5 and 7.5 and are inhibited by phenylmethane sulphonyl fluoride and by di-isopropyl fluorophosphate. the molecular weights and isoelectric points of proteinase i and proteinase ii are 30 900 and 30 000, and 4.6 and 4.3, respectively. both enzymes have a similar range of substrate specificities. the principal differences in their properties are that proteinase i is sensitive to ... | 1983 | 6355383 |
| a polyamine-sensitive mutant of aspergillus nidulans. | a mutation designated spsa1 has been induced in the putrescine (pua2) auxotroph of aspergillus nidulans which enables this mutant to grow on low concentrations of spermidine in place of putrescine. in addition, the spsa1 mutant, irrespective of putrescine requirement, is abnormally sensitive to high concentrations of spermidine, spermine or the polyamine analogue methylglyoxal bis(guanylhydrazone). when spsa1 strains are grown on medium containing spermidine, uptake of the polyamine continues at ... | 1983 | 6355384 |
| genotoxic activity of plant growth-regulating hormones in aspergillus nidulans. | three plant growth-regulating hormones, indole-3-acetic acid (iaa), indole-3-butyric acid (iba), and kinetin (6-furfuryl-aminopurine), were tested for their genetic activity in aspergillus nidulans in a plate test. the first two hormones were found to greatly increase somatic segregation in the fungus whereas kinetin was not effective. several concentrations of the plant hormones were used and it was found that increasing concentrations of iaa and iba increased mitotic segregation of the fungus ... | 1983 | 6357521 |
| the genetic location of three mutations impairing penicillin production in aspergillus nidulans. | three mutations impairing penicillin production in aspergillus nidulans, npeb, npec and nped, have been located on linkage groups iii, iv and ii, respectively, and positioned relative to other loci on these chromosomes. | 1983 | 6361214 |
| the intron of the mitochondrial 21s rrna gene: distribution in different yeast species and sequence comparison between kluyveromyces thermotolerans and saccharomyces cerevisiae. | we have screened numerous different yeast species for the presence of sequences homologous to the intron of the mitochondrial 21s rrna gene of saccharomyces cerevisiae (intron r1) and found them in all kluyveromyces species, some of the saccharomyces species and none of the other yeasts tested. we have determined the nucleotide sequence of the r1-intron in k. thermotolerans and compared it with that of s. cerevisiae. the two introns are inserted at the same position within the 21s rrna gene. the ... | 1983 | 6361491 |
| cloning and characterization of the ornithine carbamoyltransferase gene from aspergillus nidulans. | an aspergillus nidulans dna fragment composed of two adjacent sali subfragments (1.8 and 0.85 kb) that carries an argb gene complementing the yeast arg3 mutation has been isolated from two different gene libraries. hybridization results and immunological tests indicate that the cloned fragment contains the a. nidulans structural gene coding for ornithine carbamoyltransferase (otcase). using the cloned gene as a probe, the specific mrna was identified. the level of this rna observed in a. nidulan ... | 1983 | 6363209 |
| aspects of genetic interaction in hybrids of aspergillus nidulans and aspergillus rugulosus obtained by protoplast fusion. | hybrids were produced by protoplast fusion between strains of aspergillus rugulosus and mitotic master strains of aspergillus nidulans with a genetic marker on each linkage group. analysis of segregants induced by growth on benomyl revealed recombination between every pair of unlinked markers. parental combinations of markers were often recovered at significantly higher frequencies than expected. this aberrant segregation was not correlated with any particular pair of linkage-groups and was attr ... | 1983 | 6363618 |
| developmental defects resulting from arginine auxotrophy in aspergillus nidulans. | a mutant of aspergillus nidulans, isolated for inability to form asexual spores (conidia) on complete medium, was found to regain the ability to conidiate if the medium was supplemented with arginine. on minimal medium the mutant required arginine for growth but at a much lower concentration than that required for conidiation. this mutant, designated argb12, thus defines a phase-critical gene, i.e. a gene whose function is in greater demand for development than for growth. in addition to its aco ... | 1983 | 6363619 |
| bifunctionality and polarized infidelity at the hisb locus of aspergillus nidulans. | the histidine (hisb) locus of aspergillus nidulans is unusual in two ways. firstly, it is bifunctional; besides coding for imidazole glycerol phosphate (igp) dehydrase, it is required for the production of ascospores (fertility). it appears, therefore, to be partly homologous to the hisb locus of salmonella typhimurium, which codes for igp dehydrase and histidinol phosphate phosphatase. secondly, during meiosis it is often inaccurately transmitted to the progeny (infidelity). this phenomenon may ... | 1984 | 6363882 |
| disruptive effects of ethyl alcohol on mitotic chromosome segregation in diploid and haploid strains of aspergillus nidulans. | to identify, with certainty, the primary genotoxic effects of ethanol, condidia from diploid strains of aspergillus nidulans were treated during early germination with ethyl alcohol, and all the resulting segregants from large samples were analysed in detail. results were identical whether technical grade (95%), or highly purified 'absolute', alcohol was diluted to obtain the effective low levels of ethanol (3-6%). this makes it unlikely that trace contaminants, rather than ethanol itself, cause ... | 1984 | 6363912 |
| induced mutation developing delta 9-desaturase defective unsaturated fatty acid requiring mutants of aspergillus nidulans imi 72731. | 1983 | 6365749 | |
| the location and analysis of two heterokaryon incompatibility (het) loci in strains of aspergillus nidulans. | the heterokaryon incompatibility system in aspergillus nidulans has been investigated by parasexual methods. the use of complementary auxotrophs with a repeated serial transfer method or with a protoplast fusion technique has enabled heterokaryons and diploid strains to be recovered from heterokaryon incompatible combinations of strains. the effects of allelic interaction at heterokaryon incompatibility (het) loci on the morphologies of the heterokaryon and diploid colonies isolated are describe ... | 1983 | 6366116 |
| a chromosome assay method for the detection of heterokaryon incompatibility (het) genes operating between members of different heterokaryon compatibility (h-c) groups in aspergillus nidulans. | protoplast fusion has made possible the isolation of a diploid strain from haploid parents belonging to heterokaryon compatibility (h-c) groups q and gl of aspergillus nidulans. this diploid was not fully heterokaryon compatibility tests conducted between selected pairs of parasexually derived progeny strains facilitated a chromosome assay method for the detection of heterokaryon incompatibility (het) genes. despite the lack of segregation for the linkage group vi marker, it proved possible to l ... | 1983 | 6366117 |
| purification and properties of purine hydroxylase ii from aspergillus nidulans. | purine hydroxylase ii from aspergillus nidulans has been purified to near homogeneity. the enzyme has a pi of 5.7, a molecular weight of 300,000, and two subunits with molecular weight of 153,000 each. the enzyme contains 2 fad, 2 molybdenum atoms, and 4 (2 fe-2s) iron-sulfur centers per molecule and exhibits broad specificity for reducing and oxidizing substrates. among the more notable characteristics are the ability to oxidize hypoxanthine and nicotinic acid but not xanthine and virtually com ... | 1984 | 6367661 |
| transformation by integration in aspergillus nidulans. | dna-mediated genetic transformation of aspergillus nidulans has been achieved by incubating protoplasts from a strain of a. nidulans carrying a deletion in the acetamidase structural gene with dna of derivatives of plasmid pbr322 containing the cloned structural gene for acetamidase [hynes et al., mol. cell. biol. 3 (1983) 1430-1439; p3sr2] in the presence of polyethylene glycol and cacl2. the highest frequency obtained was 25 transformants per microgram of dna. no enhancement of the transformat ... | 1983 | 6368319 |
| separation and characterization of pyrimidine deoxyribonucleoside 2'-hydroxylase and thymine 7-hydroxylase from aspergillus nidulans. | partially purified preparations from aspergillus nidulans were shown to catalyze two alpha-ketoglutarate dependent dioxygenase reactions: the pyrimidine deoxyribonucleoside 2'-hydroxylase (ec 1.14.11.3) and the thymine 7-hydroxylase (ec 1.14.11.6) reactions. these reactions showed an absolute requirement for alpha-ketoglutarate and molecular oxygen and were stimulated by fe(ii), ascorbate and catalase. both reactions demonstrated a stoichiometry such that for each mole of substrate (deoxyribonuc ... | 1984 | 6370754 |
| genotoxicity of the free-radical producers ccl4 and lipoperoxide in aspergillus nidulans. | the false negative compounds, carbon tetrachloride and linoleic acid peroxide, induce somatic segregation in a. nidulans, but are negative or weak in inducing gene mutation in a haploid strain of the same organism. the other carcinogen tested, chcl3, was negative in both tests. a model involving free-radical formation is proposed to explain the results. finally, cysteamine, a free-radical scavenger, could partially counteract the genotoxicity of ccl4. the existence of carcinogens, predominantly ... | 1984 | 6371516 |
| evidence for two control genes regulating expression of the quinic acid utilization (qut) gene cluster in aspergillus nidulans. | the first three steps in quinic acid degradation in aspergillus nidulans are catalysed by highly inducible enzymes encoded by a gene cluster regulated by an adjacent control region. analysis of two non-inducible mutants has been done in diploid strains, where quta8 is recessive and all three enzyme activities are fully induced in heterozygous quta8/quta+ diploids. in contrast, quta4/quta+ heterozygous diploids show semi-dominance of the mutant allele, giving markedly diminished growth on quinic ... | 1984 | 6374025 |
| interactions of ribosomal antibiotics and informational suppressors of aspergillus nidulans. | strains of aspergillus nidulans containing informational suppressors were grown on medium containing antibiotics known to affect protein synthesis at the ribosomal level. these strains reacted in the anticipated manner: presumed ribosomal suppressors suaa101, suaa105, suac109 and sua-115 were sensitive or even hypersensitive to aminoglycoside antibiotics, whereas presumed trna-like suppressors suab111, suad103 and d108 were only slightly sensitive or wild-type in response. hygromycin and paromom ... | 1984 | 6374026 |
| spontaneous duplications and transpositions of a large chromosome segment in aspergillus nidulans. | spontaneous revertants of the leaky ade20 mutant of aspergillus nidulans were obtained as vigorous sectors emerging from stunted colonies on adenine-free medium. among the genetically heterogeneous sectors up to about 20% were recognized unequivocally as having an additional chromosome segment bearing ade20; two doses of this leaky allele permitted growth without added adenine. eleven spontaneous duplication strains of independent origin were analysed genetically. eight carried the duplicate seg ... | 1984 | 6374027 |
| s-phase, g2, and nuclear division mutants of aspergillus nidulans. | twenty-two temperature-sensitive cell cycle mutants of the fungus aspergillus nidulans, which block in interphase at restrictive temperature, were analyzed by the reciprocal shift method of jarvik and botstein (proc. nath acad. sci. u.s.a. 70:2046-2050, 1973) and hereford and hartwell (j. mol. biol. 84:445-461, 1974) to determine whether these mutations were blocked at the g1, s, or g2 phase of the cell cycle. we found five mutants to be blocked in s and nine to be blocked in g2. two of the g2 m ... | 1984 | 6376468 |
| genetic and environmental modification of gene expression in the brla12 variegated position effect mutant of aspergillus nidulans. | 1984 | 6378720 | |
| evidence for a nonsense mutation at the niad locus of aspergillus nidulans. | 1984 | 6381230 | |
| effects of mitotic and tubulin mutations on microtubule architecture in actively growing protoplasts of aspergillus nidulans. | we used immunofluorescent microscopy to characterize microtubule (mt) architecture in wild-type and mutant protoplasts of aspergillus nidulans at interphase and at mitosis. because the visualization of mts by immunofluorescence is technically difficult in intact hyphae of a. nidulans, we developed a method for removing the cell wall under conditions that do not perturb cell physiology, as evidenced by the fact that the resulting protoplasts undergo nuclear division at a normal rate and that cell ... | 1984 | 6381507 |
| mutations affecting the sulphur assimilation pathway in aspergillus nidulans: their effect on sulphur amino acid metabolism. | several sul-reg mutants of aspergillus nidulans isolated as constitutive for arylsulphatase were studied with respect to the regulation of enzymes involved in cysteine and homocysteine synthesis and to the pool of sulphur amino acids. all mutants examined showed a decreased concentration of glutathione as compared with the wild type, and all mutants, with one exception, had a decreased total pool of sulphur amino acids. the results suggest that the mutants are leaky in the sulphate assimilation ... | 1984 | 6381643 |
| induction of somatic segregation by halogenated aliphatic hydrocarbons in aspergillus nidulans. | 8 halogenated aliphatic hydrocarbons were assayed for their ability to induce somatic segregation in the mould aspergillus nidulans. induction of haploidization, mitotic non-disjunction and mitotic crossing-over was studied in heterozygous colonies exposed to the tested chemicals through the detection and phenotypic analysis of segregated sectors. the results obtained show that 1,2-dibromoethane induced all kinds of segregated sectors; 1,2-dichloroethane, allyl chloride, 2-chloroethanol, 2,2-dic ... | 1984 | 6387478 |
| mutants of aspergillus nidulans blocked at an early stage of sporulation secrete an unusual metabolite. | mutants of aspergillus nidulans defective in conidiation (asexual sporulation) can be classified according to whether they are blocked before or after induction of conidiation. mutants blocked before induction (preinduction mutants) appear to be unable to respond to the inducing stimulus and thus are defective in one of the earliest events in the sporulation process. three preinduction mutants have been isolated and characterized. each was found to exhibit the same pleiotropic phenotype: they al ... | 1984 | 6389494 |
| further studies on protoplast fusion and interspecific hybridization within the aspergillus nidulans group. | hybridization of eight species of the aspergillus nidulans group was attempted using auxotrophic mutants and protoplast fusion methods. viable fusion products were obtained from eight crosses. allodiploid hybrids were recovered from crosses involving a. nidulans with a. rugulosus, a. quadrilineatus, a. nidulans var. echinulatus and a. violaceus, although some mutants only gave heterokaryons. crosses involving these latter species also gave heterokaryons. crosses between a. nidulans and a. unguis ... | 1984 | 6389760 |
| structure and regulated expression of the spoc1 gene cluster from aspergillus nidulans. | we have previously described the organization of a 13.3 kb region of the aspergillus nidulans genome, designated spoc1, coding for multiple poly(a)+ rnas that accumulate in asexual spores but not in somatic cells. we have determined the limits of the spoc1 gene cluster by investigating the transcriptional features of 53 kb of chromosomal dna. this segment of the genome codes for at least 19 poly(a)+ rnas, some of which are transcribed from overlapping regions. the area of developmental regulatio ... | 1984 | 6392570 |
| regulation of pyrimidine salvage in aspergillus nidulans: a role for the major regulatory gene are a mediating nitrogen metabolite repression. | the synthesis of thymine 7-hydroxylase, an alpha-ketoglutarate dependent dioxygenase, is subject both to nitrogen metabolite repression and to oxygen repression, while synthesis of the other pyrimidine salvage pathway dioxygenase, pyrimidine deoxyribonucleoside 2'-hydroxylase, is subject to neither. are a300, an allele of the positive acting regulatory gene are a mediating nitrogen metabolite repression in aspergillus nidulans, considerably elevates levels of thymine 7-hydroxylase, probably alle ... | 1984 | 6394961 |
| [characteristic features of protoplast formation and regeneration in fusidium coccineum]. | the methods for preparation and regeneration of protoplasts were tested with respect to the strains of f. coccineum markedly differing in their capacity for antibiotic production, sporulation and the growth rate. it was found that the substrate used for the culture growth had a significant effect on the cell wall and sensitivity of the mycelium to lytic enzymes. an enzyme from hellix pomatia and its combination with lysozyme were used for lysing the culture. the cytological investigation of the ... | 1983 | 6404216 |
| structure of oxidized flavodoxin from anacystis nidulans. | the structure of oxidized flavodoxin from the cyanobacterium anacystis nidulans has been determined at 2.5 a resolution with phases calculated from ethylmercury phosphate and dimercuriacetate derivatives. the determination of partial sequences, including a total of 85 residues, has assisted in the interpretation of the electron density. preliminary refinement of a partial model (1072 atoms) has reduced r to 0.349 for the 10.997 reflections between 2.0 and 5.0 a with 1 greater than 2 sigma. the p ... | 1983 | 6406674 |
| determination of the sequence which spans the beginning of the insertion region in anacystis nidulans flavodoxin. | anacystis nidulans flavodoxin is one of the long chain flavodoxins (mayhew & ludwig, 1975). comparisons of its structure with the structures of shorter chain species (main text: ludwig et al., 1982) show that in a. nidulans flavodoxin most of the extra residues occupy a region adjoining the third helix and the fifth strand of parallel sheet. the sequences of peptides isolated after cyanogen bromide cleavage and after digestion with staphylococcus aureus protease, reported here, fit into the elec ... | 1983 | 6406675 |
| drift in ultraviolet sensitivity and expression of mutations during synchronous growth of cyanobacterium anacystis nidulans. | synchrony with respect to cell division and dna synthesis in cultures of anacystis nidulans was induced by a light-dark-light regimen. at periodic intervals in the cell-division cycle, dna, rna, protein contents, uv sensitivity and induction of mutations were assayed. the dna, rna and protein syntheses were periodic and reached maximal values before the separation of cells. the dna content started to increase at about the 5th hour and doubled at about the 13th hour followed by a plateau of 4-6 h ... | 1983 | 6408466 |
| the isocitrate dehydrogenase from cyanobacteria. | the present communication describes the properties of isocitrate dehydrogenase in crude extracts from the unicellular anacystis nidulans and from heterocysts and vegetative cells of nostoc muscorum and anabaena cylindrica. the activity levels of this enzyme are much higher in heterocysts than in vegetative cells of n. muscorum and a. cylindrica. isocitrate dehydrogenase is virtually inactive in vegetative cells of a. cylindrica. the enzyme is negatively regulated by the reduction charge and scar ... | 1983 | 6409049 |
| effects of mn2+, ca2+ and chlorpromazine on photosystem ii of anacystis nidulans. an attempt to establish a functional relationship of amino acid oxidase to photosystem ii. | washing with edta changes the specificity of anacystis nidulans particles having photosystem ii activities for activation by cations. a specific requirement for mn2+ and a somewhat lower specificity for ca2+ can be demonstrated in the edta-washed particles. both ions must be added to reconstitute the system evolving o2 in the light. edta-washed particles retain the l-amino acid oxidase with high specificity for the basic l-amino acids [pistorius, e. k. and voss, h. (1980) biochem. biophys. acta, ... | 1983 | 6411470 |
| the complete nucleotide sequence of a 16s ribosomal rna gene from a blue-green alga, anacystis nidulans. | the complete nucleotide sequence of a 16s ribosomal rna gene from a blue-green alga, anacystis nidulans, has been determined. its coding region is estimated to be 1,487 base pairs long, which is nearly identical to those reported for chloroplast 16s rrna genes and is about 4% shorter than that of the escherichia coli gene. the 16s rrna sequence of a. nidulans has 83% homology with that of tobacco chloroplast and 74% homology with that of e. coli. possible stem and loop structures of a. nidulans ... | 1983 | 6412038 |
| an evaluation of the mutagenic, carcinogenic and teratogenic potential of microwaves. | a notable proportion of the population is exposed to an increasing number of devices emitting microwaves, a form of non-ionizing electromagnetic radiation in the range 300-30000 mhz. the activation energy of microwave radiations is too small to directly modify any chemical bonds in the irradiated matter. at microwave frequencies the macroscopic dielectric properties of tissues are strongly determined by their water content. tissues like muscle, brain, skin, with a high water content, have higher ... | 1983 | 6412137 |
| mycologic identification of emericella nidulans and aspergillus flavus causing pulmonary infection. | 1983 | 6413149 | |
| the gene for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase is located close to the gene for the large subunit in the cyanobacterium anacystis nidulans 6301. | the gene for the small subunit (ss) of ribulose-1,5-bisphosphate carboxylase/oxygenase from a cyanobacterium, anacystis nidulans 6301, has been cloned and subjected to sequence analysis. the ss coding region is located close to and downstream from the large subunit (ls) coding region on the same dna strand. the spacer region between the ls and the ss coding regions contains 93 base pairs (bp), and has no promoter-like sequences. the coding region of a. nidulans ss gene contains 333 bp (111 codon ... | 1983 | 6415615 |
| the complete nucleotide sequence of a 23s rrna gene from a blue-green alga, anacystis nidulans. | the complete nucleotide sequence of a 23s rrna gene from a blue-green alga, anacystis nidulans, has been determined. this nucleotide sequence has 78% and 68% homologies with those of the tobacco chloroplast and escherichia coli 23s rrna genes, respectively. the 3'-terminal region of the a. nidulans 23s rrna gene has strong homology with the chloroplast 4.5s rrna. | 1983 | 6416928 |
| photoacoustic spectroscopy of anacystis nidulans. iii. detection of photosynthetic activities. | photosynthetic activities of anacystis nidulans can be detected by photoacoustic spectroscopy. algae treated by a photosynthetic inhibitor are used to provide the signal from the photochemically inactive sample. the results of these measurements correspond well with the activities which can be monitored by conventional biochemical assays. acoustic data from a. nidulans are used to obtain the action spectrum for photochemical energy storage. it is concluded that phycocyanin harvests light for bot ... | 1984 | 6421239 |
| pyruvate carboxylase from aspergillus nidulans. effects of regulatory modifiers on the structure of the enzyme. | a method is described for purification of pyruvate carboxylase from aspergillus nidulans by affinity chromatography on monomeric avidin-sepharose. the purified enzyme is homogeneous as judged by electrophoretic and immunochemical analysis. the sub-unit mr determined by electrophoresis in the presence of sodium dodecyl sulphate is 133000 +/- 5000. electron microscopic analysis of purified a. nidulans pyruvate carboxylase after negative staining with uranyl acetate reveals the presence of molecule ... | 1984 | 6421580 |
| a convener role for the cnxh gene specified component in the nadph-nitrate reductase fron aspergillus nidulans. | the role of the cnxh+ gene specified polypeptide in the formation and function of the nadph-nitrate reductase in aspergillus nidulans was examined with the use of two complementing mutant strains which were grown as forced heterocaryons in the presence of nitrate. the niad-421 structural gene mutant and the cnxh-318 co-factor gene mutant produce two components of the nadph-cytochrome c reductase co-activity which can be distinguished by their enzymatic and physical behavior. this combination ena ... | 1984 | 6423961 |
| aspergillic acids produced by mixed cultures of aspergillus flavus and aspergillus nidulans. | a mixed culture of aspergillus nidulans (gh79) and aspergillus flavus (cmi 91019b) produced two antibiotics, designated vi and vii, which were not elaborated when either fungus was grown alone. chemical and spectroscopic analysis of vi, the major component, indicated that this compound was identical to hydroxyaspergillic acid. the minor component, vii, was produced in too low a yield for its identity to be established. however, partial characterization suggests that this antibiotic also belongs ... | 1984 | 6427396 |
| the nucleotide sequences of the 5 s rrnas of seven molds and a yeast and their use in studying ascomycete phylogeny. | the sequences of the 5 s rrnas isolated from 8 ascomycete species belonging to the genera aspergillus, penicillium, acremonium and candida are reported. two of the examined strains each yielded a mixture of 3 slightly different 5 s rnas, which were individually sequenced after fractionation. a previously published sequence for aspergillus nidulans 5 s rna was found to contain errors. reconstruction of an evolutionary tree based on 5 s rna sequences showed that the 16 presently examined ascomycet ... | 1984 | 6429642 |
| vanadate and dicyclohexylcarbodiimide insensitive proton extrusion from oxygen pulsed cells of the cyanobacterium anacystis nidulans. | oxygen pulses applied to dark anaerobic suspensions of anacystis nidulans provoked immediate acidification of the external medium. the reaction was inhibited only 75% by dicyclohexylcarbodiimide and 7-chloro-4-nitrobenz-2-oxa-1,3-diazole at concentrations which completely arrested all oxidative phosphorylation. carbonyl cyanide m-chlorophenylhydrazone eliminated the acidification of oxygen pulsed cell suspensions while ortho-vanadate and diethylstilbestrol had no effect. no lag occurred between ... | 1984 | 6433918 |
| regulation of the nitrate reductase level in anacystis nidulans: activity decay under nitrogen stress. | the in vivo stability of ferredoxin-nitrate reductase from the cyanobacterium anacystis nidulans under conditions of inhibited protein synthesis has been studied in nitrate-grown cells. a light-promoted rapid decay in cellular nitrate reductase activity took place in the absence of any added nitrogen source, but not in the presence of nitrate, nitrite, or ammonium. the inactivation process seemed to proceed in two sequential steps. the first step required both light and oxygen, and was inhibited ... | 1984 | 6437330 |
| [fatty acid composition of the lipids in fungi of the genus aspergillus developing on mineral media with different carbon sources]. | this work was aimed at studying the effect of different carbon sources in the composition of mineral media on the growth of fungi belonging to the aspergillus genus and on the fatty acid composition of their lipids. a chemically-defined medium with glucose was shown to be optimal for the growth of 18 aspergillus strains and for the synthesis of lipids by them. the fatty acid composition of lipids was studied when the fungi grew in media with different carbon sources. the lipids were shown to con ... | 1984 | 6442390 |
| effect of growth substrates on phosphatases of aspergillus nidulans under heat stress. | 1980 | 6447107 | |
| molecular cloning and selection of genes regulated in aspergillus development. | over 350 clones homologous to poly(a)+ rnas that are significantly more prevalent in conidiating cultures of aspergillus nidulans than in somatic cells have been selected from a recombinant dna library formed between nuclear dna and lambda charon 4a. the procedure used for this selection involved in situ hybridization to a cdna probe which had been selectively depleted of sequences represented in somatic cells by complement hybridization. five of these clones have been characterized further. all ... | 1980 | 6449291 |
| 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 |
| mutagenesis assays with yeasts and moulds. | 1980 | 6450173 | |
| nucleotide sequence of 5s ribosomal rna from aspergillus nidulans and neurospora crassa. | the nucleotide sequences of 5s rrna molecules isolated from the cytosol and the mitochondria of the ascomycetes a. nidulans and n. crassa were determined by partial chemical cleavage of 3'-terminally labelled rna. the sequence identity of the cytosolic and mitochondrial rna preparations confirms the absence of mitochondrion-specific 5s rrna in these fungi. the sequences of the two organisms differ in 35 positions, and each sequence differs from yeast 5s rrna in 44 positions. both molecules conta ... | 1981 | 6453331 |
| microbial short-term assays with thiram in vitro. | the fungicide thiram was assayed in the following tests in vitro, with and without metabolic activation: (1) prophage lambda induction of escherichia coli k12; (2) repair test in salmonella typhimurium (strains ta1538 and ta1978); (3) induction of gene mutations in aspergillus nidulans (metha1 suppressor induction). thiram was positive in the repair test and in the a. nidulans forward-mutation test (4-6 fold increase) in the absence of metabolic activation. a slight increase was observed in prop ... | 1981 | 6454074 |
| adenosine triphosphatase of aspergillus nidulans: variation of ca2+-atpase isoenzymes. | 1981 | 6456218 | |
| atpase activity in gal mutants of aspergillus nidulans. | 1981 | 6458561 | |
| biochemical analysis of mutants defective in nitrate assimilation in neurospora crassa: evidence for autogenous control by nitrate reductase. | a biochemical analysis of mutants altered for nitrate assimilation in neurospora crassa is described. mutant alleles at each of the nine nit (nitrate-nonutilizing) loci were assayed for nitrite reductase activity, for three partial activities of nitrate reductase, and for nitrite reductase activity. in each case, the enzyme deficiency was consistent with data obtained from growth tests and complementation tests in previous studies. the mutant strains at these nit loci were also examined for alte ... | 1981 | 6460156 |
| the genetic toxicology in fungi of 4-chloromethylbiphenyl (4cmb), 4-hydroxymethylbiphenyl (4hmb) and benzyl chloride (bc). survey of the results of the u.k.e.m.s. collaborative genotoxicity trial 1981. | 1982 | 6460178 | |
| solubility of (1 leads to 3)-beta-d/(1 leads to 6)-beta-d-glucan in fungal walls: importance of presumed linkage between glucan and chitin. | in saccharomyces cerevisiae, neurospora crassa, aspergillus nidulans and coprinus cinereus most of the alkali-insoluble (1 leads to 3)-beta-d/(1 leads to 6)-beta-d-glucan of the wall can be extracted with dimethyl sulphoxide. the same fraction, and in saccharomyces cerevisiae a small additional fraction, can be extracted by a destructive procedure involving 40% naoh at 100 degrees c. the small fraction of the glucan which resists this treatment becomes soluble after a subsequent treatment with h ... | 1981 | 6460846 |
| extracellular siderophores of rapidly growing aspergillus nidulans and penicillium chrysogenum. | the highly active extracellular siderophores previously detected in young cultures of aspergillus nidulans and penicillium chrysogenum have been identified as the cyclic ester fusigen (fusarinine c), and its open-chain form, fusigen b (fusarinine b). | 1982 | 6461636 |
| [in vitro comparative study of the sensitivity of aspergillus to antifungal agents]. | minimum inhibitory concentrations (mic) of amphotericin b, 5-fluorocytosine, miconazole, tioconazole, econazole and ketoconazole were determined for 310 aspergillus strains belonging to four different species isolated from clinical specimens. econazole exhibited the best in vitro activity with mic less than or equal to 3.12 micrograms/ml for 96% of strains and less than or equal to 1.56 micrograms/ml for 68%. for amphotericin b, 69% of strains were less than or equal to 1.56 micrograms/ml and, f ... | 1984 | 6462761 |
| nondisjunction induced in mouse spermatogenesis by chloral hydrate, a metabolite of trichloroethylene. | the effects of chloral hydrate (ch), an in vivo metabolite of trichloroethylene, have been evaluated by cytogenetic observations of mouse secondary spermatocytes after ip treatment with 82.7, 165.4, or 413.5 mg/kg bw. hyper-haploid metaphases have been scored to determine whether previous observations in various nonmammalian organisms about an effect of this drug on the mitotic spindle could be confirmed in mice. at each dose, the frequencies of hyper-haploid cells have been estimated to assess ... | 1984 | 6479114 |
| isolation of aneuploid-generating mutants of aspergillus nidulans, one of which is defective in interphase of the cell cycle. | a method is described for isolating mutants potentially defective in loci involved in mitotic chromosome segregation. conditional lethal, heat-sensitive (42 degrees ) mutants were assayed at a subrestrictive temperature of 37 degrees for an inflated production of colonies displaying phenotypes and behavior patterns of whole chromosome aneuploids. of 14 mutants, three showed specificity for one disomic phenotype, whereas 11 generated colonies mosaic for different aneuploid phenotypes. this latter ... | 1984 | 6479583 |
| transhyphal electrical currents in fungi. | representative mycelial fungi from the phycomycete, ascomycete and basidiomycete groups (achlya bisexualis, neurospora crassa, aspergillus nidulans, schizophyllum commune and coprinus cinereus) all generated steady electrical currents around their hyphal tips; the generation of a transhyphal ion current may therefore be a universal characteristic of hyphal growth. as with all other tip growing organisms, positive current always entered apically and left distally; non-growing hyphae did not drive ... | 1984 | 6520604 |
| production of 2'-deoxycoformycin by the fungus emericella nidulans and its inhibitory effect on adenosine deaminase. | isolation and characterization of 2'-deoxycoformycin from the culture filtrate of the fungus emericella nidulance is described. its inhibitory effect on adenosine deaminase (ada, adenosine aminohydrolase, ec 3.5.4.4) is also described. | 1983 | 6607458 |
| two-way selection of mutants and revertants to chloroneb resistance in aspergillus nidulans. | 5 mutants of aspergillus nidulans, selected for resistance to chloroneb, were also partially dependent on it. the resistance of these mutants to chloroneb was about 20-150 times higher than that of the original strain. the resistance marker was due to a mutation in a single gene, located in linkage group iii, and behaved as a recessive character. this genetic marker was distal in relation to galal with a recombination frequency of about 30-35%. the different levels of resistance were attributed ... | 1982 | 6750388 |
| evaluation of 2 different genetic markers for the detection of frameshift and missense mutagens in a. nidulans. | 21 chemicals, known to induce missense and/or frameshift mutations directly, were assayed for their ability to forward mutate a haploid strain of a. nidulans. 2 genetic markers for forward mutations were used, namely 8-azaguanine resistance and induction of meth a1 suppressors. missense mutagens were usually active when tested with the plate-incorporation technique, whereas frameshift agents were ineffective; some of these, on the other hand, turned out to be positive when tested with a liquid-t ... | 1982 | 6750392 |
| growth characteristics of aspergillus nidulans mutans defective in carbohydrate metabolism. | several mutants aspergillus nidulans defective in carbohydrate metabolism were tested for growth on different carbon sources. d-galacturonate was found to be a substrate, useful to discriminate between mutants in pyruvate kinase, pyruvate dehydrogenase complex or pyruvate carboxylase. the results of these tests indicate how particular classes of mutants can be obtained and which substrates can be used preferentially for a rapid phenotypical screening of unknown mutants. | 1982 | 6751221 |
| isoelectric focusing and two-dimensional analysis of purified nitrate reductase from aspergillus nidulans. | the assimilatory nadph-nitrate oxidoreductase (ec 1.6.6.3) from aspergillus nidulans was purified by means of affinity chromatography and analyzed by agarose isoelectric focusing and two-dimensional electrophoresis. nadph-nitrate reductase activity was not activated by oxidation with potassium ferricyanide and was irreversibly inhibited by acrylamide. electrophoresis of nitrate reductase in 7% polyacrylamide gels resulted in rapid loss of enzyme activity. isoelectric focusing of purified enzyme ... | 1982 | 6751405 |
| mitochondrial l-rrna from aspergillus nidulans: potential secondary structure and evolution. | the alignment of gene sequences coding for a. nidulans mitochondrial l-rrna and e. coli 23s rrna indicates a strong conservation of primary and potential secondary structure of both rrna molecules, except that homologies to the 5'-terminal 5.8s-like region and the 3'-terminal 4.5s-like region of bacterial rrna are not detectable on mtdna. the structural organization of the a. nidulans mt l-rrna gene corresponds to that of yeast omega + strains: both genes are interrupted by a large intron sequen ... | 1982 | 6752884 |
| the regulation of urease activity in aspergillus nidulans. | aspergillus nidulans can utilize urea as a sole source of nitrogen but not as a carbon source. urea is degraded by a urease. mutation at any one of three genes, ureb, urec, and ured, may result in deficient urease activity. the ureb gene is closely linked to urea, the structural gene for the urea transport protein. the heat lability of ureb- revertant strain, intragenic complementation tests, and the linkage of ureb to urea suggest that ureb is the urease structural gene. the ured gene is probab ... | 1982 | 6753831 |