Publications

unidirectional gene conversion associated with two insertions in neurospora crassa mitochondrial dna.	the mitochondrial phenotype of [poky] and other extranuclear neurospora mutants is known to predominate over that of wild type in heteroplasmons. in the present work, we have investigated the interaction between wild-type and [poky] mtdnas using as many as four physical markers to distinguish the two types of mtdnas. two insertions, one of 1200 bp in eco ri-5 and the other 50 bp in eco ri-9, are identified as sites of high frequency, unidirectional gene conversion leading to their spread through ...	1979	232451
role of surface wettability in phagocytosis of neurospora crassa spores.		1979	159950
glutamine metabolism in nitrogen-starved conidia of neurospora crassa.	during nitrogen deprivation, de novo synthesis of glutamine synthetase was induced in non-growing conidia of neurospora crassa. when ammonia or glutamine was added to conidia which had been deprived of nitrogen, glutamine and arginine accumulated at a higher rate than in condia not deprived of nitrogen. the degradation of exogenous glutamine to glutamate is apparently a necessary step in the accumulation of glutamine and arginine within the conidia. in non-growing conidia, a cycle probably opera ...	1979	43352
regulation of glutamine synthetase messenger ribonucleic acid in connidia of neurospora crassa.		1979	43270
conversion of a mitochondrial precursor polypeptide into subunit 1 of cytochrome oxidase in the mi-3 mutant of neurospora crassa.	1. the cytochrome-alpha alpha 3-deficient mi-3 cytoplasmic mutant of neurospora crassa synthesizes a mitochondrial translation product which crossreacts with antibodies specific to subunit 1 of cytochrome oxidase. the immunoprecipitated polypeptide migrates more slowly during gel electrophoresis than the authentic 41 000-mr subunit 1 of the wild-type enzyme. an apparent molecular weight of about 45 000 was estimated for the mutant product. 2. radioactive labelling experiments in vivo show that t ...	1979	227683
comparative studies on the fermentative production of nucleotides by wild type neurospora crassa & an adenine auxotroph.		1979	161763
control of chromatin transcription by a cyclic adenosine 3',5'-mono-phosphate-stimulated phosphorylation in neurospora crassa.		1979	227738
genetic control of phosphorus assimilation in neurospora crassa: dose-dependent dominance and recessiveness in constitutive mutants.	mutants called nuc-1c, constitutive for alkaline phosphatase synthesis, were isolated and mapped very close to nuc-1 mutants in which this enzyme is not expressed. nuc-1 is epistatic to nuc-1c. nuc-1c acts only if it is cis to normal nuc-1 function. the preparation of partial diploids heterozygous for various nuc-1 alleles is described; nuc-1c is dominant to nuc-1+, which in turn is dominant to nuc-1. in heterocaryons with nuc-1+, nuc-1c is dominant when it is present in high proportion, but ess ...	1979	161751
genetics of arginine biosynthesis in neurospora crassa.	a large number of arginine-requiring mutants of neurospora was isolated, using a strain already partially impaired in an enzyme of the pathway. among the mutants, all previously described loci, except one, were represented, and several new loci were defined and mapped. four groups of mutants were of particular interest. first, the large group of arg-6 mutants, when tested for intragenic complementation, suggested a bifunctional gene, possibly controlling two steps in ornithine synthesis. this is ...	1979	161750
isolation and characterization of temperature-sensitive respiratory mutants of neurospora crassa.	filtration-enrichment and inositol-less death methods of mutant isolation, coupled with a screen for cyanide-insensitive respiration, proved to be highly efficient methods for isolating temperature-sensitive (ts) nuclear neurospora mutants having defective respiration. eighteen different ts respiratory mutants have been isolated. most of them are pleiotropic and defective in one or more of the following phenotypes: cytochrome aa3, b, and c (individual or multiple defects); oligomycin inhibition ...	1979	161749
nitrogen regulation of uricase synthesis in neurospora crassa.		1979	160493
biosynthesis of mitochondrial citrate synthase in neurospora crassa.		1979	160336
chitin synthase activity from the slime variant of neurospora crassa.	chitin synthase (udp-2-acetamido-2-deoxy-d-glucose:chitin 4-beta-acetamidodeoxy-d-glucosyltransferase, ec 2.4.1.16) activity from the wall-less variant of neurospora crassa (slime) was partially characterized. the slime enzyme activity was found to be similar to that reported for slime-like and wild-type chitin synthase activities with respect to the following: specific activity, particulate cell-fraction localization, activation by n-acetylglucosamine, apparent km with respect to substrate, ph ...	1979	159723
temperature-sensitive nuclear mutants of neurospora crassa deficient in mitochondrial ribosomes.	we have isolated two non-allelic nuclear mutants of neurospora crassa that are temperature-sensitive for the production of cytochromes aa 3 and b. when grown at 23 °c the mutants are virtually indistinguishable from the parent wild-type strains. when grown at 41 °c the mutants have large amounts of kcn-insensitive respiration and lack cytochromes aa 3 and b. further examination of the mutants revealed that they were extremely deficient in their capacity for mitochondrial protein synthesis when g ...	1979	24190802
effects of temperature perturbations on circadian conidiation in neurospora.	studies on the circadian rhythm of conidiation in the bd strain of neurospora crassa shear and dodge have shown that temperature step-up and step-down perturbations produce phase advances and delays, respectively. pulse-up and pulse-down treatments lead to both phase advances and delays. the resulting phase shifts can be very large, and few to no transients are observed.small amplitude temperature cycles are capable of entraining the circadian rhythm, and holding bd at low temperatures appears t ...	1979	16661081
nuclear mutants of neurospora crassa temperature-sensitive for the synthesis of cytochrome aa3. mitochondrial protein synthesis and analysis of the polypeptide composition of cytochrome c oxidase.	three previously isolated mutants of neurospora crassa, temperature-sensitive for the production of cytochrome aa3, have been further analyzed. these mutants have a slightly reduced capacity for mitochondrial protein synthesis when grown at 41 degrees c, although this relative deficiency appeared to be no greater than the deficiency in other cytochrome-aa3-deficient mutants. thermolability studies revealed that the cytochrome c oxidase purified from each of the mutants grown at 23 degrees c is n ...	1979	230040
isolation of neurospora crassa bradytrophs.	a method was developed for the isolation of neurospora bradytrophs. the bradytrophs (representing lesions in a number of pathways) were resistant to dl-p-fluorophenylalanine when growing in a leaky fashion but were sensitive when grown in the presence of their stimulating supplement.	1979	160410
purification and chemical characterization of the rodlet layer of neurospora crassa conidia.	the rodlet layer of neurospora crassa macroconidia has been purified and chemically characterized. sheets of rodlets were released from the conidial surface by vigorously shaking conidia in water. conidia were removed by filtration and low-speed centrifugation, and the rodlets were recovered from the supernatant by high-speed centrifugation. the rodlet pellet comprised 1.9% of the initial dry weight. chemical analysis was hampered by the insolubility of the rodlets. they were not solubilized by ...	1979	160407
electron microscopy of the rodlet layer of neurospora crassa conidia.	neurospora crassa macroconidia possess a regularly arranged layer of small fibers (rodlets) near the spore surface. the structure and location of this layer were studied by making surface replicas, by negative staining, by freeze-fracturing and deep-etching, and by thin sectioning. when conidia were shaken vigorously in water, the layer fragmented and became separated from the surface in sheets. negative staining of such sheets showed that the individual rodlets have a hollow central core. when ...	1979	93107
purification and some properties of uridine diphosphate n-acetylglucosamine pyrophosphorylase from neurospora crassa.	uridine diphosphate n-acetylglucosamine pyrophosphorylase (ec. 2.7.7.23) of neurospora crassa has been purified approximately 210-fold with dithiothreitol as the stabilizing agent by use of chromatographic techniques. the enzyme preparation appeared to be homogeneous when subjected to electrophoresis. the molecular weight was estimated as approximately 37 000 by gel filtration. the enzyme had an isoelectric point around ph 4.4. maximum activity of the enzyme was observed at ph 7.5. the enzyme re ...	1979	43769
the 32 s rna of neurospora crassa mitochondria is not a precursor of the mitochondrial ribosomal rnas.		1979	161331
circadian rhythms in neurospora crassa: effects of saturated fatty acids.	to assess their effects on the conidiation rhythm in neurospora, 14 saturated fatty acids from 6 to 24 carbons long were used to supplement the bd csp and bd csp cel strains. both strains express a circadian spore-forming rhythm when grown on solid media; the cel mutation confers a partial fatty acid requirement. fatty acid supplements from 8 to 13 carbons long lengthened the free-running period of bd csp cel compared with the control value of 21 h; the maximal effect (33 h) was obtained with no ...	1979	158008
characterization of the sequence complexity and organization of the neurospora crassa genome.		1979	157775
isolation of mitochondrial succinate: ubiquinone reductase, cytochrome c reductase and cytochrome c oxidase from neurospora crassa using nonionic detergent.	the electron transfer complexes, succinate: ubiquinone reductase, ubiquinone: cytochrome c reductase, and cytochrome c: o2 oxidase were isolated from the mitochondrial membranes of neurospora crassa by the following steps. modification of the contents of the complexes in mitochondria by growing cells on chloramphenicol; solubilisation of the complexes by triton x-100; affinity chromatography on immobilized cytochrome c and ion exchange and gel chromatography. ubiquinone reductase was obtained in ...	1979	226365
pleiotropic effects of ribosomal mutations for cycloheximide resistance in a double-resistant homocaryon of neurospora crassa.	pleiotropic effects of two ribosomal mutations for cycloheximide resistance were studied in a double-resistant homocaryon. the results obtained indicated that the combination of the two ribosomal mutations results in: (i) morphological abnormalities which suggest a severe distortion in the extension of cell walls and membranes; (ii) disturbance in the normal 60s-40s subunit ratio; (iii) decreased rate of cell mass production not necessarily associated with inbalance in the 60s-40s ratio; and (iv ...	1979	156720
glycogen phosphorylase from neurospora crassa: purification of a high-specific-activity, non-phosphorylated form.	a highly active glycogen phosphorylase was purified from neurospora crassa by polyethylene glycol fractionation at ph 6.16 combined with standard techniques (chromatography and salt fractionation). the final preparation had a specific activity of 65 +/- 5 u/mg of protein (synthetic direction, ph 6.1, 30 degrees c) and was homogeneous by the criteria of gel electrophoresis, amino-terminal analysis, gel filtration, and double immunodiffusion in two dimensions. the enzyme had a native molecular wei ...	1979	156719
mitochondrial ribosome assembly in neurospora. two-dimensional gel electrophoretic analysis of mitochondrial ribosomal proteins.	recent results with neurospora crassa show that one protein (s-5, mol wt 52,000) associated with the mitochondrial (mit) small ribosomal subunit is translated within the mitochondria (lambowitz et al. 1976. j. mol. biol. 107:223-253). in the present work, neurospora mit ribosomal proteins were analyzed by two-dimensional gel electrophoresis using a modification of the gel system of mets and bogorad. the results show that s-5 is present in near stoichiometric concentrations in high salt (0.5 mkcl ...	1979	158027
specificity of uracil uptake in neurospora crassa.	the specificity of uracil uptake was investigated in germinating wild-type conidia of neurospora crassa. from comparative inhibition studies, several generalizations concerning the specificity of uracil uptake can be made. (i) the tautomeric forms of uracil analogs is an important determinant of recognition by the uptake system. (ii) substituents at the 5 position of the pyrimidine ring may impose steric constraints on binding. (iii) the presence of a negative charge results in the loss of recog ...	1979	156718
the kinetics of a purified form of 3-deoxy-d-arabino heptulosonate-7-phosphate synthase (tryptophan) from neurospora crassa.	1. a method is described for the purification of a form of 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (tryptophan) that probably differs from that of the native enzyme. 2. the kinetics of the reaction catalysed by 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (tryptophan) shows that the reaction proceeds via a ping-pong bi-bi mechanism, with activation by phosphoenolpyruvate (p-prv), the first substrate, and inhibition by erythrose 4-phosphate (ery-p) the second substrate. at low ...	1979	39755
nitrogen metabolite repression of nitrate reductase in neurospora crassa: effect of the gln-1a locus.	nicotinamide adenine dinucleotide phosphate (reduced form)-nitrate reductase was freed from ammonium repression in a neurospora crassa mutant having drastically lowered glutamine synthetase activity, gln-1a. the general phenomenon of nitrogen metabolite repression required glutamine or some aspect of glutamine metabolism.	1979	37243
immunochemical characterization of glutamine synthetase from neurospora crassa glutamine auxotrophs.	glutamine synthetase derived from two neurospora crassa glutamine auxotrophs was characterized. previous genetic studies indicated that the mutations responsible for the glutamine auxotrophy are allelic and map in chromosome v. when measured in crude extracts, both mutant strains had lower glutamine synthetase specific activity than that found in the wild-type strain. the enzyme from both auxotrophs and the wild-type strain was partially purified from cultures grown on glutamine as the sole nitr ...	1979	37239
catalase of neurospora crassa. 1. induction, purification, and physical properties.		1979	37891
active transport of calcium in neurospora plasma membrane vesicles.	functionally inverted plasma membrane vesicles isolated from the eukaryotic microorganism neurospora crassa catalyze mg2+/atp-dependent ca2+ uptake. inhibitors induced efflux studies and isotope-exchange experiments indicate that the ca2+ is accumulated inside the vesicles against a concentration gradient of about 40-fold, and that the majority of the transported ca2+ is present essentially in free solution. comparisons of mg2+/atp-driven 45ca2+ uptake and [14c]scn-uptake with respect to the mg2 ...	1979	40223
spatial distribution of circadian clock phase in aging cultures of neurospora crassa.	neurospora crassa has been utilized extensively in the study of circadian clocks. previously, the clock in this organism has been monitored by observing the morphological and biochemical changes occurring at the growing front of cultures grown on solid medium. a method has been developed for assaying the clock in regions of the culture behind the growing front, where no apparent morphological changes occur during the circadian cycle. using this assay with petri dish cultures that were 2 to 7 day ...	1979	16660855
the major intracellular alkaline deoxyribonuclease activities expressed in wild-type and rec-like mutants of neurospora crassa.	over 95% of the deoxyribonuclease (dnase) activity of log-phase mycelia of neurospora crassa is expressed as single-strand (ss) specific endonucleolytic activity. this activity is associated with three nucleases (d1, d2, and d3) which after partial purification from extracts, express activity with double-strand (ds) dna as well. all three enzymes also degrade rna at approximately the same rates that they degrade ss-dna. d3 has been identified as endoexonuclease, an enzyme previously shown to hav ...	1979	157796
competitive inhibition of neurospora crassa chitin synthetase activity by tunicamycin.		1979	157718
defective splicing of mitochondrial rrna in cytochrome-deficient nuclear mutants of neurospora crassa.	recent studies have shown that the gene encoding the large (25 s) mitochondrial rrna of neurospora crassa contains an intervening sequence of 2-2.5 kilobases that is not present in the mature 25s mitochondrial rrna. earlier studies had provided evidence that mitochondrial rrnas in neurospora are synthesized via a 32s precursor rna that contains sequences for both the mature 19s and 25s rna species. the present work shows that the intervening sequence is not present in 32s rna. however, we have i ...	1979	156923
organization of the qa gene cluster in neurospora crassa: direction of transcription of the qa-3 gene.	in neurospora crassa, the enzyme quinate (shikimate) dehydrogenase catalyzes the first reaction in the inducible quinic acid catabolic pathway and is encoded in the qa-3 gene of the qa cluster. in this cluster, the order of genes has been established as qa-1 qa-3 qa-4 qa-2. amino-terminal sequences have been determined for purified quinate dehydrogenase from wild type and from uv-induced revertants in two different qa-3 mutants. these two mutants (m16 and m45) map at opposite ends of the qa-3 lo ...	1979	159203
inhibition of the acid proteinase from neurospora crassa by diazoacetyl-dl-norleucine methyl ester, 1,2-epoxy-3-(4-nitrophenoxy)propane and pepstatin.		1979	38198
role of purine base excretion in regulation of purine pools.	wild type and mutant strains of neurospora crassa excrete hypoxanthine, xanthine, and uric acid, but not adenine or inosine, when exogenous adenine is added to growing cultures. no detectable excretion occurs in the absence of adenine. the de novo pathway of purine biosynthesis was found to influence the excretion, in that a metabolic block immediately prior to imp significantly decreased the excretion, while a metabolic block immediately after imp significantly increased the excretion over that ...	1979	157418
synthesis of a larger precursor for the proteolipid subunit of the mitochondrial atpase complex of neurospora crassa in a cell-free wheat germ system.		1979	156127
mutagen-sensitive mutants in neurospora.	initial work on the fungus neurospora crassa has shown that a least two dna-repair systems exist in this eukaryote: excision repair and a mutation-prone repair. the evidence suggests that there is also a third repair system. recently, new mutagen-sensitive strains have been isolated in several laboratories, but they are not yet fully characterized. a hunt for cytoplasmically inherited uv sensitivity has failed to turn up any such mutants among 25 new uv-sensitive isolates.	1980	6452119
effects of cytochalasins on neurospora crassa. i. growth and ultrastructure.		1980	6447315
control of arginine metabolism in neurospora: flux through the biosynthetic pathway.	the flux into the arginine biosynthetic pathway of neurospora crassa was investigated using a mutant strain lacking the ornithine-degrading enzyme ornithine aminotransferase (ec 2.6.1.13). flux was measured by the increase in the sum of the radioactivity (derived from [14c]glutamic acid) in the ornithine pool, the arginine pool, and arginine incorporated into proteins. complete cessation of flux occurred immediately upon the addition of arginine to the growth medium. this response occurred prior ...	1980	6444407
effect of carbon source on enzymes and metabolites of arginine metabolism in neurospora.	the levels of enzymes and metabolites of arginine metabolism were determined in exponential cultures of neurospora crassa grown on various carbon sources. the carbon sources decreased in effectiveness (as determined by generation times) in the following order: sucrose, acetate, glycerol, and ethanol. the basal and induced levels of the catabolic enzymes, arginase (ec 3.5.3.1) and ornithine transaminase (ec 2.6.1.13), were lower in mycelia grown on poor carbon sources. arginase was more sensitive ...	1980	6444405
carbamyl phosphate synthetase a of neurospora crassa.	carbamyl phosphate synthetase a of neurospora crassa was partially purified from mitochondrial extracts. it is an extremely unstable enzyme (t 1/2 = 45 min at 25 detrees c) made up of two unequal subunits. the native enzyme has a molecular weight of approximately 175,000, and the large subunit has a molecular weight of about 125,000. both the native enzyme and its large subunit are quite asymmetric, as revealed by slow sedimentation in sucrose gradents (7.3s and 6.6s, respectively). the small su ...	1980	6243618
an enzymatic alteration secondary to adenylyl cyclase deficiency in the cr-1 (crisp) mutant of neurospora crassa: nicotinamide adenine dinucleotide (phosphate) glycohydrolase overproduction.		1980	6243107
purification and properties of neurospora crassa endo-exonuclease, an enzyme which can be converted to a single-strand specific endonuclease.		1980	6154864
the role fo glutamine synthetase and glutamine metabolism in nitrogen metabolite repression, a regulatory phenomenon in the lower eukaryote neurospora crassa.	growth of neurospora crassa on media containing nh4+ leads to the repression of a variety of permeases and alternative pathways which would generate nh4+, so called "ammonium repression." the mutant am2 which lacks nadp-gdh is not subject to ammonium repression of nitrate reductase or urea permease, but like the wild type has repressed levels of these systems when grown in the presence of proline, glutamate or glutamine. the glutamine synthetase (gs) mutant gln-1a has derepressed levels of the a ...	1980	6109228
magic-angle n-15 nmr study of nitrate metabolism of neurospora crassa.		1980	6451224
conformationally important histidine residue in glutamate dehydrogenase from neurospora crassa.		1980	6452288
reduction of ribosome activity and synthesis of stable rna in neurospora crassa.	the addition of cycloheximide (0.02 micrograms/ml) to exponentially growing cultures of neurospora crassa causes a reduction in growth rate and a decrease in the rate of protein accumulation, due to a partial inhibition of protein synthesis, while rna accumulation is unaffected for about 1 h. thus, an increased rna:protein ratio is established in the presence of the inhibitor. rna that accumulates during treatment with cycloheximide has the same characteristics as that of the control cultures an ...	1980	6452164
role of heme in the synthesis of cytochrome c oxidase in neurospora crassa.	the role of heme in the synthesis of cytochrome c oxidase has been investigated in the mold neurospora crassa. iron-deficient cultures of the mold have low levels of cytochrome oxidase and delta-aminolevulinate dehydratase, the latter being the rate-limiting enzyme of the heme-biosynthetic pathway in this organism. addition of iron to the iron-deficient cultures results in an immediate increase in the levels of delta-aminolevulinate dehydratase followed by an increase in the rate of heme synthes ...	1980	6254961
the frq locus in neurospora crassa: a key element in circadian clock organization.	four new circadian clock mutants of neurospora crassa have been isolated that alter the period length of the circadian conidiation rhythm. three of these are at the frq locus on linkage group viir, where four other clock mutants are located. in contrast to wild type, which has a period length of 21.6 hr, frq-6 has a period length of 19 hr, while frq-7 and frq-8 have period lengths of 29 hr and represent the largest effects of any single gene mutants on circadian periodicity. thus, seven mutants ...	1980	6455327
meiosis and ascospore genesis in neurospora.	mcclintock [38] and singleton [69, 70] first described and documented the meiotic sequence in neurospora crassa with particular emphasis on the chromosome cycle. in recent years different methods have been used that yield greatly improved cytological preparations. this review provides an integrated description of normal meiosis and ascospore genesis for all eight-spored neurosporas with photographs of asci stained with iron-hematoxylin. in addition, maturing asci from crosses with selected mutan ...	1980	6450683
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora crassa. isolation and sequences of several cyanogen bromide peptides from the nh2-terminal portion of the peptide chain.	previous studies of the amino acid sequence of the nad-specific glutamate dehydrogenase of neurospora crassa (ec 1.4.1.2) resulted in the assignments of peptides to four fragments, the longest being the cooh-terminal 669 residues of the protein. a further study of peptides derived by cyanogen bromide cleavage by different separation methods has yielded additional peptides that have provided new information concerning the sequence and has given overlaps of previously known sequences. this has per ...	1980	6447150
regulation and glutamic acid decarboxylase during neurospora crassa conidial germination.	glutamic acid decarboxylase (gad) from neurospora crassa was assayed in dormant and germinating conidia that had been permeabilized by toluene and methanol. n. crassa conidia contained 10 times the gad activity found in vegetativemycelia. during conidial germination, gad activity rapidly decreased to low levels before germ tubes appeared. gad activity in germinating conidia closely followed the decreasing rate of glutamic acid metabolism. inhibiting protein synthesis partially blocked the decrea ...	1980	6449504
isolation and characterization of guanine auxotrophs in neurospora crassa.	an ad-9 strain of neurospora crassa was mutagenized with ethylmethane sulfonate (5%) and selected for guanine auxotrophy. the resultant double adenine plus guanine mutant was backcrossed with wild type and a single guanine auxotroph was isolated from the progeny. in vitro assays indicated that the mutant had gmp synthetase activity comparable with wild type, but was completely lacking of imp dehydrogenase activity. the guanine requirement can therefore be explained by the mutant's inability to c ...	1980	6113044
a 15n nmr study on d-lysine metabolism in neurospora crassa.	the metabolic relationship of d-lysine, l-lysine, and l-pipecolic acid has been investigated in neurospora crassa. kinetic experiments show that radioactivity from d-lysine is efficiently incorporated into l-pipecolic acid and that this metabolite is converted to l-lysine. the alpha-amino group from d-[alpha-15n]lysine is lost in the course of its conversion to l-pipecolic acid and is trapped by pyruvate and alpha-keto glutarate to give l-[alpha-15n]alanine and l-[alpha-15n]glutamic acid. these ...	1980	6448848
genetic analysis of adenine-3 mutants induced by hycanthone, lucanthone and their indazole analogs in neurospora crassa.	ad-3 mutants induced by hycanthone, lucanthone and their indazole analogs, ia-3, ia-4 and ia-5 were studied to characterize the genetic alterations produced by these agents in neurospora crassa. the results of genetic analysis indicate that, in marked contrast to past experiments with chemical mutagens on heterokaryon 12, all of these antischistosomal agents induce a very high frequency of multilocus deletions.	1980	6452485
synchronization of dna synthesis in neurospora crassa by 2'-deoxyadenosine and spore selection.	2'-deoxyadenosine (2 mm), a dna inhibitor, was used to synchronize dna synthesis in cultures of neurospora crassa lys 3. the cultures recovered spontaneously from the inhibitor which had little or no effect o the synthesis of rna, protein or carbohydrate or on the specific growth rate of the mould. the degree of 'synchrony' of dna synthesis obtained with 2'-deoxyadenosine varied directly with the organism's specific growth rate when the latter was altered by temperature changes. a direct relatio ...	1980	6450576
physiological characterization of a neurospora crassa mutant with impaired regulation of nitrate reductase.	this report describes the isolation and characterization of a neurospora crassa mutant with an impaired regulation of nitrate reductase. glutamine, which prevents the induction of nitrate reductase in n. crassa, did so relatively ineffectively in this mutant. the mutation did not affect the regulation of all enzymes regulated by "nitrogen metabolite regulation"; it did affect the regulation of nitrate reductase, nitrite reductase, histidase, and acetamidase, as well as that of thiourea sensitivi ...	1980	6107286
regulation and function of glutamate synthase in neurospora crassa.		1980	6449930
acetylglutamate kinase. a mitochondrial feedback-sensitive enzyme of arginine biosynthesis in neurospora crassa.	the radioisotopic method used to assay acetylglutamate kinase (ec 2.7.2.8) of neurospora crassa has been shown to detect two distinct enzymatically catalyzed reactions. the enzymes were separated by differential centrifugation into a cytosolic activity and an organellar activity. both activities required atp and were thermal-labile. the cytosolic activity was insensitive to inhibition by arginine and formed a stable reaction product in the absence of hydroxylamine. the organellar activity had an ...	1980	6251078
meiosis in neurospora crassa. ii. genetic and cytological characterization of three meiotic mutants.	three recessive meiotic mutants, asc(dl95), asc(dl243) and asc(dl879), were detected by the abortion of many of their ascospores and were analyzed using both cytological and genetic methods. even though asc(dl95), asc (dl243) and the previously studied meiotic mutant, mei-1 (smith 1975; lu and galeazzi (1978), complement one another in crosses, they apparently do not recombine (delange and griffiths (1980). thus, they may represent alleles of the same gene or comprise a gene cluster. ascospore a ...	1980	6455325
meiosis in neurospora crassa. i. the isolation of recessive mutants defective in the production of viable ascospores.	a scheme has been devised for efficient isolation of recessive meiotic mutants of neurospora crassa. these mutants were detected by their reduced fertility or by the abortion of ascospores. their isolation involved the selection and screening of the strains arising from ascospores disomic (n + 1) for linkage group i (lg i), which bears the mating-type locus. these strains are self-fertile heterokaryons that contain two types of haploid nuclei of opposite mating types (a + a). selfings of these s ...	1980	6455324
some studies on histidine transport in neurospora crassa.		1980	6452407
cellular events in growth and germination of giant conidia of neurospora crassa.	during growth of conidia in 3.22 m ethylene glycol the increase in the number of the nuclei is proportional to the increase in volume only in the phase of maximum growth rate and is lower in the preceding and in the following periods of growth. dna synthesis similarly initiates later and decreases faster than protein synthesis. the dilution of ethylene glycol is followed by the germination of giant conidia, which is characterized by the absence of a lag phase, a high degree of synchrony and the ...	1980	6450046
deletion mutants of neurospora crassa mitochondrial dna and their relationship to the "stop-start" growth phenotype.	"stoppers" are a class of neurospora crassa extranuclear mutants characterized by gross deficiencies of cytochromes b and aa3 and an unusual growth phenotype which involves irregular periods of growth andnongrowth. in the present work, mtdnas from all four stopper mutants were found to contain deletions or insertions detectable by restriction enzyme analysis. [stp] mtdna consists predominantly of defective molecules which retain a 16-megadalton segment (ecori-1, -4, and -6) of wild-type mtdna (4 ...	1980	6449700
studies on phospholipase activities in neurospora crassa mycelia.	phospholipase a activity has been detected in mycelial homogenate of neurospora crassa. a submycelial fraction, obtained by differential centrifugation containing the highest specific activity of phospholipase a has been shown to contain ca. 66% phospholipase a and 34% phospholipase a activity along with lysophospholipase and degergent-stimulated phospholipase d activity. phospholipase a activity bound to n. crassa mycelia also has been observed.	1980	6449646
regulation of cytoplasmic and mitochondrial leucyl-transfer ribonucleic acid synthetases in neurospora crassa.	the production of cytoplasmic leucyl-transfer ribonucleic acid synthetase activity was found to be reciprocally proportional to that of the corresponding mitochondrial enzyme during logarithmic growth of strains of neurospora crassa with normal mitochondria. in the presence of cni-3 mutant mitochondria, production of mitochondrial enzyme activity was greatly increased whereas cytoplasmic enzyme production remained constant. the effect of cni-3 on the yield of the two enzyme activities indicated ...	1980	6448249
repression of nitrate reductase activity and loss of antigenically detectable protein in neurospora crassa.	experiments were performed to determine whether conditions which cause the rapid loss of nitrate reductase activity in neurospora crassa mycelia were accompanied by the loss of antigenically detectable nitrate reductase protein. when mycelia with nitrate reductase activity were transferred to ammonia media, there was a rapid loss in the reduced nicotinamide adenine dinucleotide-nitrate reductase activity plus the parallel loss of the reduced nicotinamide adenine dinucleotide-diaphorase and the r ...	1980	6448248
synthesis of carnitine from epsilon-n-trimethyllysine in post mitochondrial fractions of neurospora crassa.		1980	6448601
nad-specific glutamate dehydrogenase of neurospora crassa. limited action of trypsin and the presence of two distinct domains.		1980	6447151
purification and characterization of histidyl-transfer rna synthetase from neurospora crassa.	histidyl-trna synthetase (l-histidine:trnahis ligase (amp-forming), ec 6.1.1.21) has been purified 921-fold from crude extracts of lyophilized mycelia of neurospora crassa. sodium dodecyl sulfate gel electrophoresis at ph 8.9 of the purified enzyme yields one band with an apparent mr of 62 500. the estimated mr by sephadex gel filtration is 125 000. thus the native histidyl-trna synthetase of n. crassa is a dimer, composed of two identical subunits. the km values determined in the enzyme-catalyz ...	1980	6449959
inositol-limited growth, repair, and translocation in an inositol-requiring mutant of neurospora crassa.	the biochemical consequences of inositol limitation in an inositol auxotroph of neurospora crassa have been examined as a means of disclosing the cellular role of inositol. the cellular levels of inositol in the inl mutant were proportional to the concentration of inositol in the growth medium whereas inositol phosphate levels remained relatively constant at about 0.1 mumol/g (dry weight). after 72 h of growth, about 57-fold more protein per milligram (dry weight) was released by the mutant grow ...	1980	6447140
role of lipids in the neurospora crassa membrane: iii. lipid composition and phase transition properties of the plasma membrane, and its components.		1980	6446606
isolation and characterization of neurospora crassa mutants impaired in feedback control of ornithine synthesis.	thirty-two independent mutants were isolated which overcame the proline requirement of pro-3 mutations in neurospora crassa. the mutations were not revertants, appeared to be allelic, were closely linked or allelic to arg-6, and in strains unable to degrade ornithine no longer suppressed the proline requirement. the suppressor mutations did not alter the levels of biosynthetic or catabolic enzymes, yet allowed accumulation of ornithine. suppressed strains unable to degrade arginine still produce ...	1980	6245066
genome organization and characterization of the repetitive and inverted repeat dna sequences in neurospora crassa.		1980	6444301
characterization and regulation of galactose transport in neurospora crassa.	two galactose uptake systems were found in the mycelia of neurospora crassa. in glucose-grown mycelia, galactose was transported by a low-affinity (km = 400 mm) constitutive system which was distinct from the previously described glucose transport system i (r. p. schneider and w. r. wiley, j. bacteriol. 106:479--486, 1971). in carbon-starved mycelia or mycelia incubated with galactose, a second galactose transport activity appeared which required energy, had a high affinity for galactose (km = 0 ...	1980	6444943
rnase-sensitive dna polymerase activity in cell fractions and mutants of neurospora crassa.	rnase-sensitive dna polymerase activity (rsdp) was tested in different cell fractions of neurospora crassa cell types and its morphological mutants. this rsdp was found localized in the microsomal pellet fraction and absent in the purified nuclear pellets isolated from different n. crassa cell types: conidia, germinated conidia, and mycelia. this enzyme is capable of synthesizing a dna product only in the presence of all four deoxyribonucleoside-5' - triphosphates and mg2+. removal of rna from t ...	1980	6162450
cyclic amp-dependent protein kinase of neurospora crassa.		1980	6251816
control of the flux in the arginine pathway of neurospora crassa. the flux from citrulline to arginine.	the arginine pathway is a complex one, having many branch points and effector interactions. in order to assess the quantitative role of the various mechanisms that influence the flux in the pathway, the system was divided experimentally into two moieties by the introduction of a genetic block abolishing ornithine carbamoyltransferase activity. this normally produces citrulline from ornithine within the mitochondria. the endogenous citrulline supply was replaced by citrulline in the growth medium ...	1980	6449928
physiological and regulatory properties of the general amino acid transport system of neurospora crassa.	the fundamental properties of the general amino acid transport system of neurospora crassa were investigated in the conidial stage of the life cycle. the transport activity was found to be under genetic control, and an isogenic set of mutants deficient for the neutral, basic, or general amino acid transport systems and combinations thereof was constructed and used for analyzing the properties specific to the general permease. amino acid transport by this system was found to be a carrier-mediated ...	1980	6447141
nitrogen regulation of acid phosphatase in neurospora crassa.	neurospora crassa possesses a repressible acid phosphatase with phosphodiesterase activity which appears to permit it to utilize ribonucleic acid as a phosphorus and as a nitrogen source. this acid phosphatase, which is specified by the pho-3 locus, is derepressed approximately eightfold during nitrogen limitation and to an even greater extent during phosphorus limitation, but is unaffected by sulfur limitation. derepression of the enzyme did not occur when adenosine 5'-monophosphate was the sol ...	1980	6154048
circadian rhythms in neurospora crassa: oligomycin-resistant mutations affect periodicity.	nuclear mutations conferring resistance to oligomycin, a mitochondrial inhibitor, shorten the period of the circadian conidiation rhythm of neurospora crassa from the normal 21.5 hours to 18 to 19 hours and slow the linear growth rate by 30 percent. these olir mutations map very close to frq, a locus at which mutations affecting periodicity have been previously obtained. the possibilities are discussed that mitochondria are involved in circadian rhythm generation and that certain period-length m ...	1980	6444467
basic amino acids and inorganic polyphosphates in neurospora crassa: independent regulation of vacuolar pools.	at least 78%, and perhaps all, of inorganic polyphosphate is shown to be contained within the vesicles (vacuoles) of neurospora crassa, where over 97% of the soluble arginine, lysine, and ornithine pools are known to accumulate. furthermore, synthetic polyphosphate can concentrate arginine up to 400-fold from dilute (0.01 mm) solutions in equilibrium dialysis. for these reasons and because the molar ratio of basic amino acids and polyphosphate phosphorus is approximately 1, we tested the hypothe ...	1980	6445898
fructose transport in neurospora crassa.	a specific fructose uptake system (km = 0.4 mm) appeared in neurospora crassa when glucose-grown mycelia were starved. fructose uptake had kinetics different from those of intramycelial fructose phosphorylation, and uptake appeared to be carrier mediated. the only sugar which competitively inhibited fructose uptake was l-sorbose (ki = 9 mm). glucose, 2-deoxyglucose, mannose, and 3-o-methyl glucose were noncompetitive inhibitors of fructose uptake. incubation of glucose-grown mycelia with glucose ...	1980	6445895
the neurospora plasma membrane ca2+ pump.	plasma membrane vesicles isolated from the eukaryotic microorganism neurospora crassa by the concanavalin a method catalyze mg2+-atp dependent 45ca2+ accumulation. since the atp-responsive vesicles are functionally inverted, the ca2+ transport system presumably operates as a ca2+ exit pump in the intact cell. the mechanism of the ca2+ pump system involves two components: 1) an electrogenic, proton-translocating atpase (ec 3.6.1.3), which utilizes the chemical energy of atp hydrolysis to generate ...	1980	6245937
guanosine metabolism in neurospora crassa.	two aspects of guanosine metabolism in neurospora have been investigated. (a) the inability of adenine mutants (blocked prior to imp synthesis) to use guanosine as a nutritional supplement; and (b) the inhibitory effect of guanosine on the utilization of hypoxanthine as a purine source for growth by these mutants. studies on the utilization of guanosine indicated that the proportion of adenine derived from guanosine may be limiting for the growth of adenine mutants. in wild type, adenine is prod ...	1980	6447534
studies of the structure--function relationships of neurospora crassa pyruvate kinase: interaction with blue dextran--sepharose and cibacron blue 3g-a.	blue dextran--sepharose and cibacron blue 3g-a interact with pyruvate kinase of neurospora crassa. the enzyme is readily released from the substituted sepharose column by elution with 0.17 m potassium phosphate buffer (ph 7.9), or 2 mm fructose 1,6-diphosphate (fdp), but not with either of the substrates, adp and phosphoenolpyruvate (pep), at 2 mm. cibacron blue 3g a is a noncompetitive inhibitor of pyruvate kinase with respect to both substrates. it appears to compete with the allosteric effect ...	1980	6446967
intracellular localization, isolation and characterization of two distinct varieties of superoxide dismutase from neurospora crassa.	1. neurospora crassa was found to contain two distinct superoxide dismutases. 2. most of the activity is associated with the cytosolic fraction and was shown to be the cu/zn-containing form of the protein. 3. mitochondria isolated from neurospora crassa showed two distinct superoxide dismutases: a cyanide-sensitive cu/zn-containing protein and a cyanide-insensitive form which probably contains manganese. 4. localization experiments, using selective marker enzymes and digitonin fractionation, ind ...	1980	6249266
purine biosynthesis and its regulation in neurospora crassa.	purine biosynthesis and its regulation was studied in neurospora crassa by the incorporation of label from [14c]formate into total cellular purines. in general, the purine biosynthesis resulted in slightly more cellular guanine than adenine nucleotides. the acid-soluble pool however, contained more adenine compounds than guanine. exogenous adenine was found to be an effective regulatory of the proximal steps of the de novo biosynthesis, while both adenine and guanine were equally effective in re ...	1980	6445209
characterization of protoporphyrin as the physiological regulatory of delta-aminolevulinate dehydratase in neurospora crassa.		1980	6445207
stimulation of the alternative oxidase of neurospora crassa by nucleoside phosphates.	the alternative-oxidase-mediated succinate oxidase activity of neurospora crassa decreases drastically when mitochondria are fractionated into submitochondrial particles or treated with deoxycholate. the activity, however, can be completely restored in the presence of nucleoside 5'-monophosphates. the purine nucleoside 5'-monophosphates are more effective than the pyrimidine homologues. 5'-gmp gives a 10-fold stimulation of the alternative-oxidase-mediated succinate oxidase activity in submitoch ...	1980	6447503
purification and characterization of uricase, a nitrogen-regulated enzyme, from neurospora crassa.		1980	6446884
polyglutamylfolate synthesis in neurospora crassa: changes in pool size following growth in glycine- and methionine-supplemented media.		1980	6449176
nuclear division cycle in neurospora crassa hyphae under different growth conditions.	treatment with picolinic acid blocked neurospora crassa nuclei in g1, and recovery from the treatment allowed a synchronous wave of deoxyribonucleic acid synthesis to occur. nuclei, which appeared as compact globular bodies during the period of blockage, assumed a ring shape during the following s phase, which was also maintained in the g2 phase. the proportion of compact globular nuclei was much higher in hyphae growing at lower rates, whereas that of ring nuclei increased when the hyphae were ...	1980	6445357
the electron spin resonance spectrum of a suicidal fungus.	the electron spin resonance spectrum of a suicidal inositol auxotroph of neurospora crassa, previously used as a model of cellular aging, exhibits a high-spin fe(iii) signal whose intensity increases as a function of the mutant's "senescence". surprisingly, the intensity of the signal is further enhanced by the exogenous antioxidant nordihydroguaiaretic acid, which reportedly decreases the rate of senescence.	1980	6248694
sequence complexity and abundance classes of nuclear and polysomal polyadenylated rna in neurospora crassa.	the sequence complexity of nuclear and polysomal polyadenylated rna in neurospora crassa has been investigated by an analysis of the kinetics of rna : cdna hybridizations. there are about 2000 different messenger rnas organized into three abundance classes of low, medium and high complexity which contain approx. 10, 150 and 1800 sequences, respectively. taking 1300 nucleotides as the average length of mrna, the total sequence complexity of polyadenylated polysomal rna was calculated to represent ...	1980	6154479