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the influence of microinjected phalloidin on locomotion, protoplasmic streaming and cytoplasmic organization in amoeba proteus and physarum polycephalum.microinjected phalloidin induces both time and concentration-dependent changes in morphology and motility of amoebae and acellular slime moulds. in a. proteus injection of a 10(-3)m solution of the drug causes a separation of cortical hyaline plasma from central granular plasma. simultaneously protoplasmic streaming and cellular locomotion are lost irreversibly. lowering the concentration of phalloidin to 2 x 10(-4)m results in a reversible disturbance; amoebae recover after 30 to 60 minutes and ...1978710672
poly(adenylic acid) degradation by two distinct processes in the cytoplasmic rna of physarum polycephalum. 1978718854
size distribution and maturation of newly replicated dna through the s and g2 phases of physarum polycephalum.the size distribution of newly made dna and the dynamics of size maturation of progeny dna molecules were studied in the synchronous s and g2 phases of physarum polycephalum. pulse labeling of dna and analysis of the products on alkaline sucrose gradients showed that synthesis of primary replication units (which will also be referred to as "okazaki" fragments) occurred throughout the s period. pulse and pulse-chase experiments revealed a distinct pattern of size maturation. an apparently linear ...1978729005
effect of ionizing radiation on nucleoside metabolism in physarum polycephalum. 1978734057
control of ornithine decarboxylase activity in physarum by polyamines.the addition of putrescine, spermidine, or spermine, to cultures of physarum polycephalum rapidly reduced the activity of ornithine decarboxylase, with maximal inhibition, 80-90%, occurring after 90 min. this response was not due to a decrease in enzyme molecules, but rather to the rapid conversion of the active enzyme to a stable, catalytically less active form. this response to exogenous polyamines was not accompanied by the appearance of a macromolecular inhibitor (antizyme) either free, or b ...1978738271
toxicity of heavy metals and insecticides on slime mold physarum polycephalum.toxicity of heavy metals and insecticides on the slime mold physarum polycephalum was investigated in order to examine and estimate with ease the toxicity of environmental and occupational contaminants and also to study the effects of various agents on the cell membrane. changes in survival time and in membrane potential of the slime mold were measured using a double chamber method. the results obtained suggest that their toxicity for the slime mold is accompanied by some change in the cell memb ...1978739566
the structure of chromatin containing dna complementary to 19 s and 26 s ribosomal rna in active and inactive stages of physarum polycephalum. 1978742889
change of the nuclear pore frequency during the nuclear cycle of physarum polycephalum.the change of the nuclear pore frequency during the nuclear cycle of synchronous plasmodia of physaru- polycephalum was investigated. counts were made on platinum-carbon replicas of isolated nuclei. pore numbers varied markedly at any given time of the nuclear cycle, possibly due to the variable dna contents of the nuclei. the average pore frequency per nucleus increased from 336 at 1 h after mitosis to 770 at 50 min before the subsequent mitosis. the results suggest a quantitative relation betw ...1978748340
comparison of susceptibility to staphylococcal nuclease and behaviour in metrizamide gradients of normal and 5-bromodeoxyuridine-substituted chromatin from physarum polycephalum.replacement of 20--30% of thymine by 5-bromodeoxyuridine in chromatin dna of physarum polycephalum does not cause any visible change in a typical, regular pattern of dna products obtained upon digestion of chromatin with staphylococcal nuclease. the time course of digestion is similar for normal and substituted chromatin even under conditions when the nuclease cleaves preferentially the dat regions in dna. 5-bromodeoxyuridine label does not significantly affect the dna/protein ratio in chromatin ...1978752203
molecular cytochemistry: incorporation of fluorescently labeled actin into living cells.actin labeled with 5-iodoacetamidofluorescein has been incorporated into the functional pool of actin in chaos carolinensis and physarum polycephalum by direct microinjection. the functional activity of the labeled actin has been analyzed at three levels of organization as: (a) with the purified actin, (b) in motile extracts of cells, and (c) in living motile cells. the labeled actin exhibited normal polymerization and activated myosin atpase to a similar extent as unlabeled controls. labeled ac ...1978345279
ultrastructural localization of beta-d-galactan in the nuclei of the myxomycete physarum polycephalum.the acellular slime mold physarum polycephalum produces an extracellular sulfated and phosphorylated beta-d-galactan which was recently isolated from the nuclei of this organism. this polysaccharide has now been localized in the nuclei of p. polycephalum by electron microscopy using a specific "sandwich" technique: thin sections of p. polycephalum microplasmodia were incubated with the ricinus communis lectin specific for d-galactose residues. the bound lectin was then localized with gold granul ...1978356891
enzymes for rna sequence analysis. preparation and specificity of exoplasmodial ribonucleases i and ii from physarum polycephalum. 1978563399
a new method for the purification of rna polymerase ii (or b) from the lower eukaryote physarum polycephalum. the presence of subforms.the dna-dependent rna polymerase ii or b from the lower eukaryote physarum polycephalum has been purified to apparent homogeneity by a new method employing poly(ethylene imine) precipitation and elution, and heparin-sepharose affinity chromatography. the method is readily scaled up or down and affords a purification of over 5000-fold with a yield of 35-45%. the procedure is easy to perform and can be carried out in less than three days even on a large scale. furthermore, it gives enzyme of highe ...1978563790
structure of a beta-galactan isolated from the nuclei of physarum polycephalum.a sulfated and phosphorylated beta-d-galactan ([alpha]d+8degrees) was isolated from the nuclei of the acellular slime mould physarum polycephalum. the polysaccharide was isolated from cesium chloride gradients during the preparation of ribosomal dna and purified. the purified galactan contained 89% galactose, 2.5% phosphate and 9.6% sulfate groups and had an average degree of polymerisation of 560. periodate degradation and permethylation studies indicated the presence of mainly (1 leads to 4)-, ...1978564213
the use of netropsin with cscl gradients for the analysis of dna and its application to restriction nuclease fragments of ribosomal dna from physarum polycephalum.netropsin binds to dna in caesium chloride density gradients and reduces the density of the dna. the dna is saturated at a netropsin/dna weight ratio of about 6 and the change in density, deltarho, at saturation is given by deltarho = -109 (da + dt content)1.87 mg/ml for the six dnas tested covering da + dt contents from 0.28 to 0.69. at lower netropsin/dna ratios the observed density shifts are consistent with a two-site model for netropsin binding to dna. netropsin approximately doubles the re ...1978564266
control of rna transcription in nuclei and nucleoli of physarum polycephalum. 1978564291
studies on pulse-labelled rna during the mitotic cycle of physarum polycephalum by subnuclear fractionation.a method is described for the isolation of pulse-labelled rna from nuclei and subnuclear fractions of physarum polycephalum. at all times during interphase the nucleolar rna consisted mainly of a 34-s rrna precursor with only small amounts of 26-s and 19-s rrnas. the nucleoplasmic rna consisted of predominantly mature 26-s rrna with small amounts of 19-s rrna and a 30-s rna species. the 30-s rna component displayed different labelling kinetics from the rrna precursors. a low molecular weight rna ...1978564354
the structure of nucleolar chromatin in physarum polycephalum.the nucleolar dna of physarum polycephalum has been differentially labelled with 3h-thymidine and the structure of the nucleolar chromatin investigated by digestion with micrococcal nuclease. nucleolar chromatin which had been labelled in g2 phase of the cell cycle and then digested before mitosis had an identical dna repeat length to main band dna (165 +/- 5 base pairs) but there was a definite indication that the rate of digestion was faster for nucleolar dna than for main band dna. nucleolar ...1978565509
dna replication in physarum polycephalum: bidirectional replication of dna within replicons.the direction of replication of dna within replicons of physarum polycephalum was studied by pulse-labelling with 5-bromouracil-deoxyriboside (brdurd) and 3h-adenosine deoxyriboside (dado), followed by ultraviolet- (uv) -photolysis and analysis of molecular weights of single strand dna fragments on alkaline sucrose gradients. newly made dna within replicons at all stages of completion is split in two equal halves upon uv irradiation when brdurd was given at the time of initiation of dna synthesi ...1978565510
cadmium modification of nucleolar ultrastructure and rna synthesis in physarum polycephalum. 1978565959
the heterogeneity of cytoplasmic deoxyribonucleic acid polymerase from physarum polycephalum.cytoplasmic dna polymerase (dna deoxynucleotidyltransferase, ec 2.7.7.7) was partially purified from physarum polycephalum. the first step of the purification procedure utilized the fact that the enzyme on gel filtration behaves in anomalous fashion. the second step was either ion-exchange chromatography or sucrose-density-gradient centrifugation. the partially purified dna polymerase was heterogeneous and at least four species with different sedimentation coefficients (5.5s, 7.2s, 8.6s and 11.5 ...1978566101
metabolic stability of the extrachromosomal ribosomal rna genes in the slime mould physarum polycephalum.the rrna genes of the slime mould physarum polycephalum are located on free, linear dna molecules of a discrete size, mr=38x10(6). using an isotope dilution technique we have examined the metabolic stability of these extrachromosomal genes during active, balanced growth. microplasmodia, prelabelled with [3h]thymidine, were used to prepare synchronous surface plasmodial cultures which were subsequently grown on unlabelled medium. the gross synthesis of ribosomal dna was then determined over three ...1978566198
deoxyribonucleic acid polymerase from physarum polycephalum. properties of the major cytoplasmic activity in exponentially growing microplasmodia.dna polymerase was purified 1000-fold from the cytoplasm of microplasmodia of the myxomycete physarum polycephalum. the activity was found in two forms exhibiting molecular weights of 204000 and 116000 respectively. both forms eluted together from dna-cellulose and deae-sephadex columns. the stokes radii were 6.5 and 5.5 nm. the sedimentation coefficients were 7.6 and 5.2 s. the frictional ratios of 1.69 suggest a highly hydrated and/or an asymmetric structure of the molecule. the enzyme-catalyz ...1978566199
successful demonstration of an elusive cell coat in amebae.cell coats were cytochemically demonstrated for the first time in myxamebae of fulig- septica, didymium iridis, dictyostelium discoideum, cavostelium apophysatum, and amebae of naegleria grubei. the stain enhances the cell coats of physarum polycephalum plasmodia, ceratiomyxa fruticulosa myxamebae, and acanthamoeba sp. cell coats usually unstained by cationic dyes stain intensely with the aid of the new cytochemical protocol utilizing 0.5% alcian blue in the primary fixative and 0.05% ruthenium ...1978566325
theoretical approach to the effects of extremely low frequency electromagnetic fields on physarum polycephalum. 1978566449
ribosomal dna in spores of physarum polycephalum.dna was isolated from plasmodia, spores and newly hatched amoebae of the slime mould physarum polycephalum. the dna preparations were fractionated in cscl gradients and each fraction hybridised to combined 19 s + 26 s rrna. in all three dna preparations hybridisation was found to be limited to satellite dna (rho = 1.714 g/cm3) and at saturation was found to reach a level of 0.16--0.18 % of total dna. the main band of nuclear dna (rho = 1.702 g/cm3) did not hybridise appreciably. further experime ...1978566559
chromatin structure of physarum polycephalum plasmodia and amoebae. 1978566679
periodic organisation of foldback sequences in physarum polycephalum nuclear dna.nuclear dna from the slime mould physarum polycephalum is shown to contain interspersed inverted repeat sequences, such that denatured fragments of dna containing pairs of these sequences form intra-chain duplexes under appropriate conditions. the organisation and distribution of the nucleotide sequences responsible for the formation of foldback structures in physarum dna have been investigated using the electron microscope. the majority of foldback duplexes have sizes ranging up to 800 base pai ...1978566909
[spatio-temporal analysis of contraction dependent surface movements in physarum polycephalum (author's transl)].plasmodial veins of physarum polycephalum were investigated by combining cinematographical and tensiometrical methods. veins remaining on their original growing substrate show characteristic surface movements resulting from an intrinsic contraction automaticity. radial and longitudinal components of surface movements were registered simultaneously. both contraction activities show identical frequencies, in contrast to results derived from experiments with isolated veins. there is only one genuin ...1978567599
cyclic production of tension force in the plasmodial strand of physarum polycephalum and its relation to microfilament morphology.cyclic contraction and relaxation of plasmodial strands of physarum polycephalum were measured under both isotonic and isometric conditions, and their relation to changes in microfilament (mf) morphology was investigated. the contraction-relaxation rhythm of a strand segment was insignificant and irregular immediately after isolation from the mother plasmodium. it became regular half an hour later when local minute rhythms were synchronized spontaneously. if a strand kept under isotonic conditio ...1978569161
altered nucleosome structure containing dna sequences complementary to 19s and 26s ribosomal rna in physarum polycephalum.the localization of dna sequences coding for ribosomal rna was studied by hybridization of purified ribosomal rna to dna from chromatin fragments prepared by limited digestion of physarum nuclei with staphylococcal nuclease. the 32p-labeled 19s and 26s rna hybridized to dna from nucleosome monomers, dimers, trimers, and higher oligomers, separated by sucrose gradient centrifugation, although the level of hybridization to dna from nucleosome fractions was less than the level of hybridization to u ...1978274703
cycloheximide-induced mitotic delay in physarum polycephalum.cycloheximide pulses applied to physarum polycephalum surface plasmodia delay mitosis. pulses applied in g2 cause a delay of mitosis which is linearly dependent on the phase in the cell cycle at which the pulse is applied. a 30 min pulse of 10 micrograms/ml cycloheximide starting in g2 at time t after mitosis induces an excess delay (delay in excess of pulse duration) of the next mitosis of (0.55) t-1.3 h. the excess delays induced by 7 h pulses during g2 are at most 1 h larger. pulses applied l ...1978299645
dna replication in physarum polycephalum: uv photolysis of maturing 5-bromo-deoxyuridine substituted dna.combinations of 5-bromodeoxyuridine (brdurd) and 3h-deoxyadenosine (3h-dado) short pulses were given in the synchronous dna-replication period of physarum polycephalum. after a chase period, uv-photolysis products were analyzed on alkaline sucrose gradients. this strategy has allowed the following conclusions. a) at the time of master-initiation of dna replication, points separated by 1.1-2.2x10(7) daltons of single strand dna may initiate dna synthesis. b) among these, only selected groups of r ...1978309109
replacement of endoplasm with artificial media in plasmodial strands of physarum polycephalum. effects on contractility and morphology. 1978151630
an adenosine-3',5'-monophosphate activated adenylate cyclase in the slime mold physarum polycephalum. 1978208869
activation of histone kinase in g2 phase of the cell cycle in physarum polycephalum. 1978212304
chemotaxis: not a prerequisite for plasmodia coalescence in physarum polycephalum. 1978215149
adenylate cyclase and cyclic amp phosphodiesterase activity during the mitotic cycle of physarum polycephalum. 1978216353
[regulation of some hydrolases in the myxomycete physarum polycephalum (proceedings)]. 197881005
[yellow pigments of the myxomycete physarum polycephalum (proceedings)]. 197881006
measurement of chemotaxis in the slime mold physarum polycephalum. 197830643
an immunological approach to the isolation of factors with mitotic activity from the plasmodial stage of the myxomycete physarum polycephalum.nuclear divisions in plasmodia of physarum polycephalum were advanced by applying immunologically purified plasmodial extracts of late g2 phase on the surface of plasmodia which were 1.5 h before the third mitosis. the purification of g2 extracts was achieved by interaction of antibodies prepared against the antigens of early s phase plasmodia with the antigens of late g2 plasmodia. there was no advancement of mitosis by extracts prepared from early s phase plasmodia. untreated g2 extracts did n ...1978400913
the activity of guanylate cyclase and cyclic gmp phosphodiesterase during synchronous growth of the acellular slime mould physarum polycephalum. 197934395
purification of an alkaline nuclease from physarum polycephalum.an alkaline nuclease was purified from microplasmodia of physarum polycephalum. the nuclease, active on denatured dna and rna and free of contamination by other nucleolytic activities, appeared to be a zinc-metallo protein. the enzyme was only active under conditions, where zn2+ were retained in the enzyme. loss of zinc occurred by the chelating action of edta, egta or ampholines, by acid of highly alkaline ph conditions or by high ionic strength. the addition of zncl2 to compensate losses, rest ...197941584
the role of regulation of cell speed in the behavior of physarum polycephalum amoebae. 197941731
patterns of nucleic acid synthesis in physarum polycephalum. 197995053
[ultrastructural study of the nucleolar cycle in physarum polycephalum using edta preferential stain for rnp (author's transl)]. 1979104873
selective modification of positive chemotaxis in the true slime mold physarum polycephalum by ethylenediaminetetraacetic acid treatment.the plasmodium of the true slime mold physarum polycephalum was treated with edta or egta and the effect of the treatment on the chemotactic response was examined by measuring the chemotactic motive force with the double-chamber method. the results obtained were as follows: (1) the treatment of the plasmodium with 5 mm edta (ph 7.0, 20 min) did not give any significant effect on the protoplasmic streaming or motility. (2) the plasmodium treated with edta exhibited no chemotactic response to non- ...1979114232
identification of sarcoplasmic reticulum-like system in physarum polycephalum. 1979116871
ca2+-binding modulator protein in protozoa and myxomycete.ca2+-binding protein with the properties of brain modulator protein of 3,5-cyclic nucleotide phosphodiesterase was identified in physarum polycephalum plasmodia and in euglena gracilis and amoeba proteus cells by urea polyacrylamide gel electrophoresis and activation of cyclic nucleotide phosphodiesterase and of myosin light chain kinase.1979222487
purine metabolism in microplasmodia of physarum polycephalum.the uptake and utilization of purine nucleosides and purines in microplasmodia of physarum polycephalum were investigated. the results revealed a unique pattern, namely that exogenous purine nucleosides are readily taken up and metabolised, while free purine bases are hardly taken up. the pathways of incorporation have been elucidated in studies with whole cells and with cell-free extracts. the ribonucleosides (adenosine, inosine and guanosine) can be converted into ribonucleotides in two ways; ...1979223640
cyclic 3',5'-amp phosphodiesterase in physarum polycephalum. i. chemotaxis toward inhibitors and cyclic nucleotides.the effect of several inhibitors of the enzyme cyclic 3',5'-amp phosphodiesterase as chemoattractants in physarum polycephalum was examined. of the compounds tested, 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (roche 20-1724/001) and 1-ethyl-4-(isopropylidinehydrazino)-1h-pyrazolo-(3,4-b)-pyridine-5-carboxylic acid ethyl ester, hydrochloride (squibb 20009) were the most potent attractants. 3-isobutyl-1-methyl xanthine, theophylline, and morin (a flavanoid) were moderate attractants and someti ...1979228761
cyclic 3',5'amp phosphodiesterase in physarum polycephalum. ii. kinetic properties.some kinetic characteristics of soluble and particulate cyclic 3',5'-amp phosphodiesterases from physarum polycephalum are presented. the nature of enzyme inhibition by various agents is reported. the relationship between various enzyme inhibitors and their reported chemotactic properties in physarum is examined. the results suggest that the chemoattractant effect of several inhibitors may be related to their ability to inhibit the particulate and extracellular phosphodiesterases, but is unrelat ...1979228762
thymidine kinase enzyme variants in physarum polycephalum. in vitro interconversion of the enzyme variants.isoelectric focusing of plasmodial extracts of physarum polycephalum demonstrated the presence of several multiple enzyme variants of thymidine kinase, which appear sequentially during the nuclear division cycle. variants (a) + (a1) are the only enzyme variants found in the late g2-phase, whereas the variants (c) + (c1) are only present at the time of mitosis and s-phase (1, 2). evidence is presented that multiple forms of thymidine kinase (a) + (a1) with high pi arise by dephosphorylation of a ...1979230187
isolation of a minichromosome containing the ribosomal genes from physarum polycephalum.the ribosomal genes of physarum polycephalum are located on linear dna molecules (rdna) of 38 x 10(6) daltons present in each nucleolus in 100--200 copies. the rdna is not part of the large chromosomal dna. these molecules have now been solubilized in the form of transcriptionally active deoxyribonucleoprotein complexes from nucleoli purified through percoll gradients. the ribosomal chromatin (rdnp) sediments in sucrose gradients as a homogeneous fraction with an approximate sedimentation coeff ...1979420794
post-fusion somatic incompatibility in plasmodia of physarum polycephalum.high-resolution autoradiography has been used to establish that during the incompatibility reaction that follows fusion between plasmodia of a 'killer' and a 'sensitive' strain of the myxomycete physarum polycephalum, the nuclei of the sensitive strain are selectively damaged, enclosed in vacuoles and eliminated from the cytoplasm. this damage is visible as increased chromatin condensation and nucleolar segregation. nuclear envelopes of both strains show blebbing, and there is an increase in the ...1979422675
ribosomal phosphoproteins in physarum polycephalum. 1979426826
accessibility of the ribosomal genes to micrococcal nuclease in physarum polycephalum.in physarum polycephalum most genes coding for ribosomal rna are not integrated in chromosomes, but are located in many copies in the nucleolus as plasmid-like palindromic dna molecules. to find out whether coding sequences of rdna are organized in a chromatin-like structure similar to that of bulk chromatin, nuclei were treated with micrococcal nuclease and dna fragments were isolated. from bulk chromatin multimers of a basic unit of 170-180 base pairs were obtained. nuclease fragmented dna hyb ...1979427166
presence of the epsilon-(gamma-glutamic)lysine crosslink in cellular proteins.the epsilon-(gamma-glutamic)lysine bond is a covalent interaction which has been found to crosslink polypeptide chains of a number of extracellular proteins. among known covalent bonds crosslinking protein chains, it is unique in that it is formed directly by enzymatic catalysis, a property which may also endow glu-lys crosslink formation with important intracellular functions. we found glutamic-lysine bonds to be present in the procaryote, escherichia coli, in primitive eucaryotes such as the s ...1979427186
fluctuations in proline and other free amino acids during the mitotic cycle of the myxomycete physarum polycephalum.1. during synchronous growth of the acellular slime mould physarum polycephalum the free amino pool had two maxima, one of 650 units [nmol/plasmodium dry weight (mg)] at metaphase and the other of 780 units in mid g2 with minima of 550 units before and after mitosis. 2. proline formed 20--25% of the total pool with aspartic acid, glutamic acid, threonine, valine, leucine, lysine and arginine making up 55% of the pool. 3. the fluctuation of proline during the mitotic cycle was quite different fro ...1979436826
distribution of inverted repeat sequences in nuclear dna from physarum polycephalum.inverted repeat sequences, capable of forming stable intra-chain foldback duplexes, are shown using electron microscopy to be located in over 90% of fragments of nuclear dna from physarum polycephalum. a statistical treatment of the data indicates that, on average, foldback sequence foci are spaced every 7,000 nucleotides and that they are distributed uniformly amongst the dna chains. the majority of inverted repeat sequences give rise to the simple types of foldback structure observed in dna fr ...1979436838
temperature-sensitive mutants of physarum polycephalum: viability, growth, and nuclear replication.using a selfing strain of physarum polycephalum that forms haploid plasmodia, we have isolated temperature-sensitive growth mutants in two ways. the negative selectant, netropsin, was used to enrich for temperature-sensitive mutants among a population of mutagenized amoebae, and, separately, a nonselective screening method was used to isolate plasmodial temperature-sensitive mutants among clonal plasmodia derived from mutagenized amoebae. complementation in heterokaryons was used to sort the mut ...1979438137
polyadenylated rna in the lower eukaryote physarum polycephalum.utilizing a method which quantitatively extracts high molecular weight rna, including intact precursor as well as mature ribosomal rnas, adenylated molecules have been isolated from nuclear- and cytoplasmic-enriched fractions of physarum microplasmodia labeled with [3h]-uridine. electrophoretic analysis of denatured adenylated rna from the nuclear-enriched fraction indicated the presence of a population of large molecules not found in the cytoplasmic-enriched fraction.1979440302
dna replication in physarum polycephalum: electron microscopic and autoradiographic analysis of replicating dna from defined stages of the s-period.electron microscopic and autoradiographic analysis of replicating dna from physarum showed that replication occurs at a rate of 0.4 micron/min/per replicon and that replicons of size 10--15 mu occur in temporal clusters with an average of about 4 replicons per cluster. these results are compared with previous hydrodynamic measurements and with those obtained in other organisms.1979450701
unique sequence arrangement of ribosomal genes in the palindromic rdna molecule of physarum polycephalum.r-loop and restriction mapping procedures reveal the organization of coding regions at each end of the giant rdna palindrome of physarum polycephalum. a 19s coding region of 2.10 +/- 0.21 kb is located at each end of a very long central spacer (35.64 +/- 2.08 kb). an internal spacer of 1.66 +/- 0.12 kb lies distal to the 19s gene. the 5.8s rrna coding region is located in this spacer. the 26s gene lies distal to the internal spacer. the 26s gene is unusual among those of eukaryotes in that it co ...1979450702
inhibitory action of nephroma water extracts on the metabolism of physarum polycephalum. 1979451053
characterisation of ribosomal satellite in total nuclear dna from physarum polycephalum.the distinctive properties of satellite dna molecules containing the genes for ribosomal rna in physarum polycephalum permits their identification in total, unfractionated nuclear dna in the foldback form, after denaturation and fast annealing. using the electron microscope the location and properties of three characteristic regions containing tandemly-repeated, inverted sequences have been investigated. at least two additional regions, also containing tandem repeats, are shown to be present and ...1979454607
physarum thymidine kinase. a step or a peak enzyme depending upon temperature of growth.the variations of thymidine kinase or atp:thymidine 5'-phosphotransferase (ec 2.7.1.21) during the cell cycle of physarum polycephalum plasmodia have been studied at two extreme physiological temperatures: 22 degrees c and 32 degrees c. at 22 degrees c the enzyme activity increases near mitosis and stays constant during late s and g2 phases, exhibiting the typical pattern of a 'step enzyme'. but at 32 degrees c thymidine kinase activity goes through a maximum 1 h 30 min after mitosis and decreas ...1979456364
identification of mrna in the slime mold physarum polycephalum.using a differential extraction procedure which had previously been shown to yield one nucleic acid fraction enriched in cytoplasmic rna and another enriched in nuclear rna, we have been able to isolate two polyadenylated rna populations from microplasmodia of physarum polycephalum. the poly(a)-containing rna from the cytoplasmic-enriched fraction accounts for approximately 1.2% of the cytoplasmic nucleic acid, has a number-average nucleotide size of 1339+/- 39 nucleotides, and has been shown, i ...1979456382
plasmalemma invaginations of physarum dependent on the nutritional content of the plasmodial environment.quantitative estimates of plasmalemma invaginations in plasmodial veins of physarum polycephalum were made under different conditions of nutrition. pronounced differences were observed dependent on the nutritional content of the substrate. there was a decided increase in the number of plasmalemma invaginations in plasmodial veins grown on substrates containing absorbable food substances compared to veins migrating on non-nutrient substrates. this observation supports the proposition that the nut ...1979457813
kinetics of mating in physarum polycephalum. 1979460299
changes in cytoplasmic dna-binding phosphorproteins during the cell cycle of physarum polycephalum. 1979466702
studies on microplasmodia of physarum polycephalum v: electrical activity of different types of microplasmodia and macroplasmodia.results obtained by three different electrophysiological methods delivered mainly oscillating potentials (independently of the type of organization of physarum polycephalum) with an average period length of 1 min 21 sec. this value is in good statistical agreement with corresponding data for the periodical oscillation of the shuttle streaming (1 min 47 sec) and coincides also with the radial tensiometric contractile activity (1 min 34 sec). the investigation favours the hypothesis that ion fluxe ...1979476837
the effect of growth on translation of polyadenylated messenger ribonucleic acid in physarum polycephalum [proceedings]. 1979478124
character and distribution of foldback sequences in nuclear deoxyribonucleic acid from physarum polycephalum [proceedings]. 1979478125
cycle specific association of nascent chromatin with nuclear envelope components in physarum polycephalum.the action of heparin on isolated nuclei derived from different phases of the mitotic cycle in plasmodia of physarum polycephalum was studied. heparin addition at two-fold excess over dna concentration to nuclei in mg-free low ionic strength buffer (10 mm tris-hc1, 10 mm na2 hpo4, ph = 8) releases 60-80% of chromatin from s, g2, and mitotic phase nuclei. the rna/protein ratio of herparin-solubilized cromatin is constant through s and g2 phases, but rises about two-fold at early prophase coincide ...1979482128
repair of radiation-induced dna double-strand breaks in isolated nuclei of physarum polycephalum. 1979482602
ribosomes of physarum polycephalum. subunits and protein composition.ribosomes from physarum polycephalum were purified. optimal conditions for preparation and stability of subunits were determined. kcl concentration above 200 mm induced protein dissociation from the subunits. it was observed that dissociated ribosomes were more stable in a low ionic strength buffer than in 200 mm kcl, where the 40 s was preferentially degraded by ribonucleases. ribosomal proteins were analyzed by two-dimensional gel electrophoresis. the first dimension was carried out at ph 8.6 ...1979486531
initiation of transcription of ribosomal deoxyribonucleic acid sequences in isolated nuclei of physarum polycephalum: studies using nucleoside 5'-[gamma-s]triphosphates and labeled precursors. 1979497155
specificity of sterol-glucosylating enzymes from sinapis alba and physarum polycephalum.1. sinapis alba l. seedlings contain glycosyltransferase catalyzing the synthesis of sterol glucosides in the presence of udpglucose as sugar donor. the major activity occurs in the membranous fraction sedimenting at 300--9000 x g. successive treatment of the particulate enzyme fraction with acetone and triton x-100 affords a soluble glucosyltransferase preparation which can be partly purified by gel filtration on sephadex g-150. molecular weight of the glucosyltransferase is 1.4 . 10(5). appare ...1979497231
[proceedings of the 4th group of european work on the biology of physarum polycephalum: biochemical aspect and cell cycle study. innsbruck-march 19-23, 1979]. 1979497248
cadmium modification of nucleolar function and structure in physarum polycephalum. 1979505456
regulation of thymidine kinase synthesis during the cell cycle of physarum polycephalum by the heat-sensitive system which triggers mitosis and s phase. 1979510403
large scale isolation of ribosomal dna from giant surface cultures of physarum polycephalum. 1979510543
temperature-sensitive mutants of physarum polycephalum--expression of mutations in amoebae and plasmodia. 1979510920
oscillatory contraction activity in physarum.the plasmodia of physarum polycephalum show different oscillatory phenomena (time period approximately 1.3 min) in their contraction behaviour and their protoplasmic flow. the force generating system for these phenomena is cytoplasmic actomyosin. the biochemical nature and location(s) of the oscillator(s), i.e. the clock governing these phenomena are unknown. the following locations are discussed as possible sites of the oscillator: (1) cytoplasmic actomyosin, (2) the energy supply system, (3) i ...1979512576
thymidine kinase enzyme variants in physarum polycephalum. kinetics and properties of the enzyme variants.thymidine kinase variants of physarum polycephalum separated by repeated deae-cellulose chromatography have been characterized. the enzyme variants show similar catalytic properties (e.g., substrate specificity, ph optimum) and molecular weights, as judges by their sedimentation in sucrose gradients. however, they differ significantly with respect to pi, inhibition by dttp and thermostability, and they have slightly different km values for deoxythymidine as a substrate.1979521445
the influence of carbohydrases on the growth of fungal pathogens in vitro and in vivo.mixtures of mycolytic enzymes from various sources release protoplasts from living fungal tissue under suitable conditions. such enzyme mixtures obtained from coprinus comatus (mycolase i), physarum polycephalum (mycolase ii) and lycoperdon pyriforme (mycolase iii) are of low toxicity in mammals when given parenterally and are able to cure experimental systemic fungal infections in mice when administered alone or in conjunction with normally ineffective levels of conventional antimycotic drugs s ...1979523359
dna synthesis in a sub-nuclear preparation isolated from physarum polycephalum. 1979526308
1,4-alpha-glucan phosphorylase from the slime mold physarum polycephalum. purification, physico-chemical and kinetic properties.glycogen phosphorylase from macroplasmodia of physarum polycephalum was purified 76-fold to homogeneity. the native enzyme migrated as a single protein band on analytical disc gel electrophoresis coinciding with phosphorylase activity. after reduction in the presence of sodium dodecylsulfate one protein band was detectable which corresponded to an mr of 93 000. the molecular weight of the native enzyme determined by gel sieving or gradient-polyacrylamide gel electrophoresis was 172000 and 186000 ...1979527584
isolation of a residual protein structure from nuclei of the myxomycete physarum polycephalum.a nuclear framework structure has been obtained from isolated interphase nuclei of physarum polycephalum by extraction with 2.5 m nacl and subsequent digestion with dnase. whole-mount electron micrographs showed a nuclear lamina containing residual pore structures associated with the fibrous internal matrix. the matrix was continuous with fibrillar remnants of the nucleolus. the structure was shown to consist of 2 major polypeptides of 23,000 and 36,500 daltons as well as 30 to 40 minor polypept ...1979528582
microbubbles in replicating nuclear deoxyribonucleic acid from physarum polycephalum.clusters of microbubbles, represent probable sites of newly initiated dna synthesis, were identified in nuclear dna from physarum polycephalum by using the electron microscope. their presence is associated specifically with s-phase. each microbubble corresponds in size to a replicating segment of dna about 100-5000 nucleotide residues in length. the dna structures containing microbubbles are metastable, and revert to native dna in the presence of moderate concentrations of formamide used to prep ...1979534510
spectral analysis of fluorescence of 8-anilino-1-naphthalenesulfonate in chemoreception with a white plasmodium of physarum polycephalum. evidence for conformational change in chemoreceptive membrane. 1979549637
characterization of an endogenous transcription inhibitor from physarum polycephalum.a substance has been purified from isolated nuclei of physarum polycephalum by equilibrium and velocity gradient centrifugations, ion exchange chromatography and gel filtration which has a high molecular weight, can be labeled in vivo with 32p, is heat stable and resistant to amylases, proteases, nucleases and phosphodiesterase but is sensitive to phosphatases or hydrolysis. this material consists of phosphate and glycerol. it selectively inhibits in vitro transcription of rna polymerases, predo ...1979155953
some properties of physarum actinin. a regulatory protein of actin polymerization.a factor termed physarum actinin was isolated and partially purified from plasmodia of a myxomycete, physarum polycephalum. when physarum actinin was mixed with purified physarum or rabbit striated muscle g-actin in a weight ratio of about 1 actinin to 9 actin and then the polymerization of g-actin induced, g-actin polymerized to the ordinary f-actin on addition of 0.1 m kcl. however, it polymerized to mg-polymer on addition of 2 mm mgcl2. the reduced viscosity (etasp/c) of the mg-polymer was 1. ...1979157167
the development of sporulation competence in physarum polycephalum. 1979159846
translational regulation of polysome formation during dormancy of physarum polycephalum.the translational activity of actively growing microplasmodia and dormant microsclerotia of physarum polycephalum was investigated by analyzing the distribution of ribosomes in polysomes. microplasmodial post-mitochondrial fractions contained substantial amounts of polysomes and ribosomal subunits but very few native monosomes. during the starvation period which preceded microsclerotium formation, polysome levels remained constant, whereas the subunit titer began to increase. during encystment r ...1979315405
activity of some dehydrogenase enzymes in mitochondria from physarum polycephalum.1. coupled mitochondria were isolated from exponentially growing physarum polycephalum. 2. activity of malate dehydrogenase (oxalacetate reduction) was 10.9 mumol/min/mg protein; the apparent km was 64 microm. 3. the activity of nadp-isocitric dehydrogenase (idh) was 110 nmol/min/mg with apparent km of 35 microm. 4. nad-idh showed allosteric properties with amp as a positive modulator. the apparent km for the unmodulated activity, 2 mm, was decreased to 0.95 mm by 0.13 mm amp. 5. succinic dehydr ...1979318427
polyamine-mediated phosphorylation of a nucleolar protein from physarum polycephalum that stimulates rrna synthesis.an acidic nucleolar phosphoprotein with a subunit m(r) of 70,000 was purified as an apparent dimer of 139,000 from isolated nuclei of the slime mold physarum polycephalum. the protein was purified without the aid of strong dissociating agents after its selective phosphorylation in isolated nuclei by a polyamine-mediated reaction. its amino acid composition resembled that of a nucleolar phosphoprotein from novikoff hepatoma ascites cells. the phosphoprotein stimulated rrna synthesis 5-fold by rna ...1979288043
degradation of bacterial lipopolysaccharide by the slime mould physarum polycephalum.a strain of the acellular slime mould physarum polycephalum degraded lipopolysaccharides (lps) from a variety of bacteria. the anticomplementary (ac) activity of lps was greatly reduced, as was the content of lauric, myristic, and palmitic acids, and the ability to sensitize erythrocytes to agglutination by antibody. these results indicate that physarum has enzymes which reduce the lipid a moiety of lps. in contrast, 2-keto-3-deoxy-d-manno-actanoic acid (kdo), immunodominant sugars, and beta-hyd ...1979373869
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