| resistance of selected saprobic and zoopathogenic fungi to cycloheximide. | spore germination was used as an assay to measure the sensitivities of selected fungi (achlya bisexualis, cladosporium sp., trichophyton mentagrophytes and microsporum gypseum) to cyclohexamide and to determine their abilities to adapt to the drug. two patterns of response were noted. the saprobes, a. bisexualis and cladosporium sp., demonstrated acquired resistance. spores from hyphae previously exposed to cycloheximide either germinated in the presence of concentrations of the drug that comple ... | 1978 | 632807 |
| inhibition of dna synthesis by cycloheximide and blasticidin-s is independent of their effect on protein synthesis. | the effects of cycloheximide and related glutarimide antibiotics on dna synthesis in achlya bisexualis coker and a. couch were compared to those of other protein synthesis inhibitors, puromycin, p-fluorophenylalanine and blasticidin-s. the inhibitors had no significant effects on intrahyphal pool sizes of dttp, dctp, atp, utp and ctp, nor on the specific activity of the dttp pool labelled by [3h] thymidine. dna was the sole acid-insoluble product of [3h]-thymidine incorporation. cycloheximide, i ... | 1977 | 849443 |
| differential uptake and metabolism of sitosterol and cholesterol by achlya, pythium, and phytophthora species. | the relative ability of isolates of achlya bisexualis and a. ambisexualis and isolates of pythium and phytophthora to take up and metabolize sitosterol and cholesterol was studied. species of pythium and phytophthora took up cholesterol and sitosterol efficiently, whereas achlya species took up booth sterols inefficiently. species of pythium and phytophthora produced a polar metabolite and esters from sitosterol as they did from cholesterol. achlya species did not produce the polar metabolite fr ... | 1975 | 1148933 |
| [phospholipase a1 activity of achlya bisexualis coker: influence of lecithins in the culture media]. | | 1975 | 1239306 |
| molecular phylogenetic analysis of actin genic regions from achlya bisexualis (oomycota) and costaria costata (chromophyta). | actin genic regions were isolated and characterized from the heterokont-flagellated protists, achlya bisexualis (oomycota) and costaria costata (chromophyta). restriction enzyme and cloning experiments suggested that the genes are present in a single copy and sequence determinations revealed the existence of two introns in the c. costata actin genic region. phylogenetic analyses of actin genic regions using distance matrix and maximum parsimony methods confirmed the close evolutionary relationsh ... | 1991 | 1779434 |
| chemotropism and branching as alternative responses of achlya bisexualis to amino acids. | hyphae of achlya bisexualis growing on lean media orient their extension towards a source of amino acids, and also put forth branches. micropipettes were used to generate gradients of amino acids in the vicinity of individual hyphae. phenylalanine and methionine were the most powerful attractants: 0.04 mm amino acid in the pipette produced reorientation, and higher concentrations made the hyphae curl around the pipette and grow into its tip. hyphae detected gradients as low as 5% across their wi ... | 1989 | 2628544 |
| transcellular ion currents during sporangium development in the water mould achlya bisexualis. | changes in the pattern of electric currents that accompany the transformation of growing hyphae of achlya bisexualis into sporangia have been examined. when hyphae were transferred to a non-nutrient buffer, they continued to extend for several hours and then gave rise to sporangia. throughout this process, current (positive charge) flowed into the apical region that corresponds approximately to the future sporangium. the current ceased after the crosswall appeared. the sporangium then remained e ... | 1988 | 2848924 |
| electrobiology of fungal hyphae. | hyphae of many fungi drive electric currents through themselves. in achlya bisexualis the current is carried by protons which enter the apical region by symport with amino acids and are expelled distally. the proton current may play a role in the spatial localization of apical growth. | 1985 | 2856375 |
| transcellular proton current in achlya bisexualis hyphae: relationship to polarized growth. | growing hyphae of achlya bisexualis drive an electric current through themselves, such that positive charge flows into the apical region (the anterior 300 micron) and exits distally along the hyphal trunk. they also generate a gradient of extracellular ph, such that the medium surrounding the apex is slightly alkaline whereas that along the hyphal trunk is acid. to explore the genesis of these gradients and their relationship to polarized extension, we examined the effects of changes in the comp ... | 1988 | 2894029 |
| ionophores and cytochalasins modulate branching in achlya bisexualis. | hyphae of achlya bisexualis growing on a medium deficient in amino acids elongated but produced relatively few branches. branching was enhanced by three classes of compound: cytochalasins a and e, the calcium ionophores a23187 and ionomycin and proton ionophores such as tetrachlorosalicylanilide (tcs), carbonylcyanide m-chlorophenylhydrazone (cccp), and carbonylcyanide p-trifluoromethoxyphenylhydrazone (fccp). we suggest that the effects of cytochalasins reflect the disruption of a microfilament ... | 1986 | 3086491 |
| electrophysiological properties of achlya hyphae: ionic currents studied by intracellular potential recording. | the electrical properties of the water mold achlya bisexualis were investigated using intracellular microelectrodes. hyphae growing in a defined medium maintained a membrane potential (vm) of -150 to -170 mv, interior negative. under the conditions used here, this potential was insensitive to changes in the inorganic ion composition of the medium. changes in external ph did affect vm, but only outside the physiological ph range. by contrast, the addition of respiratory inhibitors caused a rapid ... | 1986 | 3958044 |
| [demonstraction of a phospholipase a activity in achlya bisexualis after culture on lecithin]. | | 1973 | 4196418 |
| [characterization of a phospholipase a from achlya bisexualis coker cultivated on lecithins]. | | 1974 | 4451669 |
| the ribosomal cistrons of the water mold achlya bisexualis. | | 1973 | 4716956 |
| protein synthesis during the differentiation of sporangia in the water mold achlya. | during the synchronous differentiation of sporangia in the absence of added nutrients, the water mold achlya bisexualis (coker and couch) actively synthesized protein. inhibition of protein synthesis at any time during the sporulation process completely inhibited further differentiation. large changes in the rate of radioactive amino acid uptake resulted in changes in the specific activity of the cellular amino acid pool. the rate of protein synthesis was calculated from the amino acid pool spec ... | 1973 | 4745427 |
| the developmental patterns of lysosomal enzyme activities during ca2+-induced sporangium formation in achlya bisexualis. i. acid phosphatase. | | 1974 | 4836529 |
| evidence for diploidy in achlya bisexualis based on inheritance of cycloheximide resistance. | | 1974 | 4841598 |
| differential effects of cycloheximide and other inhibitors of protein synthesis on in vivo ribosomal rna synthesis in achlya bisexualis. | | 1974 | 4842020 |
| cycloheximide inhibition of the dna-dependent rna-polymerase i of achlya bisexualis. | | 1972 | 5057918 |
| isolation of a sex hormone from the water mould achlya bisexualis. | | 1967 | 6059532 |
| 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 |
| growing hyphae of achlya bisexualis generate a longitudinal ph gradient in the surrounding medium. | growing hyphae of achlya bisexualis were found to generate a longitudinal ph gradient in the surrounding medium; the medium adjacent to the tip was slightly more alkaline than the bulk phase, while that near distal parts was acidic. the profile of external ph paralleled that of electric current, as measured with a vibrating probe; the apical alkaline zone corresponded to the region of current inflow. in organisms grown in complete medium, both current flow and apical alkalinization were inhibite ... | 1984 | 6527127 |
| electron microscopy of achlya deoxyribonucleic acid sequence organization. | electron microscopic analysis of reassociated deoxyribonucleic acid (dna) from the aquatic fungus achlya bisexualis revealed details of the sequence arrangement of the inverted repeats and both the highly and moderately repetitive sequence clusters. we used the gene 32 protein-ethidium bromide technique for visualizing the dna molecules, a procedure which provides excellent contrast between single- and double-stranded dna regions. long (greater than 6-kilobase) dna fragments were isolated after ... | 1981 | 6985459 |
| deviation from the usual relationships between the temperature, the growth rate, the fatty acid composition and the lipid microviscosity of four different fungi (mucor mucedo, aspergillus ochraceus, scopulariopsis brevicaulis, achlya bisexualis. | | 1981 | 7306120 |
| sequence analysis of duplicated actin genes in lagenidium giganteum and pythium irregulare (oomycota). | southern analysis of genomic dna identified multiple-copy actin gene families in lagenidium giganteum and pythium irregulare (oomycota). polymerase chain reaction (pcr) protocols were used to amplify members of these actin gene families. sequence analysis of genomic coding regions demonstrated five unique actin sequences in l. giganteum (lg-ac1, 2, 3, 4, 5) and four unique actin sequences in p. irregulare (pi-ac1, 2, 3, 4); none were interrupted by introns. maximum parsimony analysis of the codi ... | 1994 | 8064873 |
| differential effects of analogs of cycloheximide on protein and rna synthesis in achlya. | analogs of the glutarimide antibiotic cycloheximide were tested for their effect on growth and incorporation of proline and uridine into acid-insoluble material in achlya bisexualis. each of the compounds tested had reduced antibiotic activity as compared to cycloheximide. the effects of the antibiotics on protein and rna synthesis were varied. while cycloheximide inhibited both protein and rna synthesis immediately, two of the analogs inhibited proline incorporation without effect on uridine in ... | 1974 | 11400436 |
| heavy metals have different effects on mycelial morphology of achlya bisexualis as determined by fractal geometry. | the morphological response, as measured by changes to mycelial area, radial extension and border fractal dimension, of the oomycete achlya bisexualis to cu, co, hg, zn and cd at concentrations of between 0.05 and 3 mm is described. all of the metals decreased mycelial area and radial extension. border fractal dimension increased in the presence of cu, co and hg with individual hyphae extending out beyond the mycelial margin. in the presence of 3 mm hg these hyphae displayed spiral growth. zn and ... | 2001 | 11470371 |
| [screening, cloning and sequence analysis of the gene for pyruvate kinase from achlya bisexualis cdna library]. | the gene for pyruvate kinase, which is involved in glycolysis and catalyze the biochemical reaction from phosphoenolpyruvate to pyruvate, was screened, cloned and sequenced from non-photosynthetic oomycetes, achlya bisexualis cdna library. the size of the gene is about 1.6 kb. the amino acid sequence of the gene was deduced using the gcg program. on basis of analysis by the on-line psort ii program the deduced amino acid sequence showed that the pyruvate kinase expressed by the gene was located ... | 2001 | 11725642 |
| image analysis of hyphal morphogenesis in saprolegniaceae (oomycetes). | because of their wide range of apical morphology, several members of saprolegniaceous fungi (oomycetes) were chosen to examine concordance with the vesicle supply center (vsc) model of hyphal morphogenesis. two computer routines were devised to measure diameter changes over long stretches of hyphae and to test compatibility with the theoretical hyphoid shape, y = xcot(xv/n). in all four genera examined, the apex followed closely the contour described by the hyphoid equation; divergences became e ... | 2004 | 14761790 |
| two distinct distributions of f-actin are present in the hyphal apex of the oomycete achlya bisexualis. | we show that two distinct distributions of f-actin are present in the hyphal apex of the oomycete achlya bisexualis, that have been chemically fixed with a combination of methylglyoxal and formaldehyde and stained with alexa phalloidin. in approximately one half of the hyphae examined, an f-actin depleted zone within the apical f-actin cap was observed. the remaining hyphae had a continuous apical cap. in live, growing hyphae two types of cytoplasmic organization were observed at the tips, one i ... | 2004 | 15047875 |
| turgor regulation in hyphal organisms. | turgor regulation in two saprophytic hyphal organisms was examined directly with the pressure probe technique. the ascomycete neurospora crassa, a terrestrial fungi, regulates turgor after hyperosmotic treatments when growing in a minimal medium containing k(+), mg(2+), ca(2+), cl(-), and sucrose. turgor recovery by n. crassa after hyperosmotic treatment is concurrent with changes in ion transport: hyperpolarization of the plasma membrane potential and a decline in transmembrane ion conductance. ... | 2004 | 15465389 |
| a beta4 integrin-like protein co-localises with a phosphotyrosine containing protein in the oomycete achlya bisexualis: inhibition of tyrosine phosphorylation slows tip growth. | we present immunocytochemical data that indicate the presence of, and a close association between beta4 integrin-like proteins and proteins containing phosphorylated tyrosine residues in the oomycete achlya bisexualis. when hyphae were plasmolysed, these proteins were present in wall-membrane attachment sites where there was also f-actin. a combination of immunoblots, elisa, and a coupled enzyme assay suggest that phosphorylation may occur by both autophosphorylation and through the action of a ... | 2005 | 15893255 |
| molecular identification of the turf grass rapid blight pathogen. | rapid blight is a newly described disease on turf grasses, primarily found on golf courses using suboptimal water for irrigation purposes. on the basis of shared morphological characteristics, it has been proposed that the rapid blight pathogen belongs to a genus of stramenopiles, labyrinthula, which had been known to cause disease of marine plants only. we have collected 10 isolates from four species of turf grass in five states and sequenced portions of the ssu (18s) rdna gene from each to pro ... | 2005 | 16389967 |
| invasive hyphal growth: an f-actin depleted zone is associated with invasive hyphae of the oomycetes achlya bisexualis and phytophthora cinnamomi. | we have compared f-actin patterns in invasive and non-invasive oomycete hyphae. in achlya bisexualis an f-actin depleted zone is present in 70% of invasive but only 9% of non-invasive hyphae. in phytophthora cinnamomi these figures are 74 and 20%, respectively. thus, the f-actin depleted zone appears to be associated with invasive growth. tem images indicate that it is unlikely to represent areas of vesicle accumulation. measurements of turgor indicate no significant increase under invasive cond ... | 2006 | 16517186 |
| dna sequence organization in the water mold achlya. | experiments are described that characterize the organization of dna sequences in the water mold achlya bisexualis. these experiments demonstrate that repetitive and single copy sequences in the achlya genome are arranged in a long-period interspersion pattern. estimates of the spacing intervals between repetitive and single copy dna indicate, however, that the interspersion pattern in achlya is longer than has been previously reported in other eukaryotes. these data and measurements of structura ... | 1977 | 16592446 |
| aphanomyces invadans and ulcerative mycosis in estuarine and freshwater fish in florida. | in the spring of 1998, the florida fish and wildlife research institute received numerous reports of lesioned or ulcerated fish primarily from the st. lucie estuary on the southeast coast of florida, an area known since the late 1970s for lesions of the ulcerative mycosis (um) type. from these and archived reports, as well as others received from different areas of florida, we documented that diseased specimens had randomly distributed skin ulcers (usually reddened or hemorrhagic) with raised ir ... | 2007 | 18236628 |
| pathogenicity studies with the fungi aphanomyces invadans, achlya bisexualis, and phialemonium dimorphosporum: induction of skin ulcers in striped mullet. | based on isolations from naturally infected fish in florida, we investigated the role of the fungi aphanomyces invadans, achlya bisexualis, and phialemonium dimorphosporum in the etiology of ulcerative mycosis (um) in striped mullet mugil cephalus. we injected healthy striped mullet subcutaneously with secondary zoospores of four oomycete isolates: two concentrations (50 and 115 zoospores/ml) of sjr (an endemic isolate of aphanomyces invadans in american shad alosa sapidissima from the st. johns ... | 2007 | 18236631 |
| an investigation of the effects of ca²+ channel inhibitors on branching and chemotropism in the oomycete achlya bisexualis: support for a role for ca²+ in apical dominance. | in an attempt to better understand branching and chemotropism, we describe the effects of ca²+ channel inhibitors on these processes in achlya bisexualis, using a branch induction technique and whole plate assays. branching appears to be a two step process with the initial formation of a bump from which a branch emerges. verapamil increased numbers of branches in whole plate assays and decreased the distance from the first branch to the tip. in induction assays verapamil increased the number of ... | 2010 | 21050891 |
| hyphal tip growth in achlya bisexualis. i. distribution of 1,3-{beta}-glucans in elongating and non-elongating regions of the wall. | we have approached the problem of hyphal tip growth by comparing the cell wall composition of elongating and non-elongating regions of the hyphae of achlya bisexualis. to ensure that we could distinguish between elongating and non-elongating hyphae, light microscopic observations were used to determine the rates of elongation under growing and non-growing conditions. when elongation was measured in 10 min intervals it was found to consist of fluctuating periods of fast and slow growth rates, in ... | 2002 | 21156496 |
| hyphal tip growth in achlya bisexualis. ii. distribution of cellulose in elongating and non-elongating regions of the wall. | cellulose has been localized in the hyphal wall of elongating and non-elongating hyphae of achlya bisexualis using a direct enzyme-colloidal-gold method. a number of controls, including several different types of fixation, support the idea that this labeling is specific for cellulose. both tem and sem were used and they gave similar results. the apical area of an elongating hypha lacks cellulose, but the same area of a non-elongating hypha contains cellulose. we have used specific culture media ... | 2002 | 21156497 |
| a pressure gradient facilitates mass flow in the oomycete achlya bisexualis. | we have used a single cell pressure probe and observed movement of microinjected oil droplets to investigate mass flow in the oomycete achlya bisexualis. to facilitate these experiments, split petri dishes that had media containing different sorbitol concentrations (and hence a different osmotic potential) on each side of the dish were inoculated with a single zoospore. an initial germ tube grew out from this and formed a mycelium that extended over both sides of the petri dish. hyphae growing o ... | 2016 | 26608611 |
| an investigation into plasmolysis in the oomycete achlya bisexualis reveals that membrane-wall attachment points are sensitive to peptides containing the sequence rgd and that cell wall deposition can occur despite retraction of the protoplast. | the structure and function of membrane-wall attachment sites in walled cells, and how these relate to animal focal adhesions, is an area that is poorly understood. in view of this, we investigated how membrane-wall attachments that form upon plasmolysis, respond to peptides that disrupt animal focal adhesions. the degree of cytoplasmic disruption during plasmolysis was also investigated. upon hyperosmotic challenge, the protoplast in hyphae of the oomycete achlya bisexualis typically retracted i ... | 2012 | 23051153 |
| an elastomeric micropillar platform for the study of protrusive forces in hyphal invasion. | oomycetes and fungi are microorganisms whose pathogenic (invasive) growth can cause diseases that are responsible for significant ecological and economic losses. such growth requires the generation of a protrusive force, the magnitude and direction of which involves a balance between turgor pressure and localised yielding of the cell wall and the cytoskeleton. to study invasive growth in individual hyphae we have developed a lab-on-a-chip platform with integrated force-sensors based on elastomer ... | 2017 | 28959802 |
| relationship between growth and the electrical current of fungal hyphae. | the hyphae of filamentous fungi exhibit a highly polarized mode of cell extension and all generate electrical currents around their hyphal tips. of the 13 fungi that have been examined with the vibrating probe, 12 normally have positive electrical current entering the growing tip. however, the apical current is always outward in allomyces macrogynus. in those organisms that have inward apical currents, outward currents are found occassionally and transiently in hyphae that extend at normal rates ... | 1989 | 29300590 |