DETECTION OF VIRUS-LIKE PARTICLES IN THE COREMIA OFPENICILLIUM CLAVIFORME

1975 ◽  
Vol 17 (4) ◽  
pp. 525-533 ◽  
Author(s):  
H. C. Lai ◽  
K. Zachariah
Keyword(s):  
Ribonucleic Acid ◽  
Ecological Significance ◽  
Wild Type ◽  
Virus Like Particles ◽  
Mutant Strains ◽  
Fungal Viruses

A double-stranded ribonucleic acid (dsRNA) was isolated from coremial extracts of wild type P. claviforme, by methylated-albumin kieselguhr chromatography. Differential centrifugations of the coremial extracts from WT and Sh mutant strains yielded two classes of virus-like particles (VLP), of dimensions 25-30 nm, and 50-70 nm. The possible ecological significance of fungal viruses is discussed.

scholarly journals The hobo Transposable Element Excises and Has Related Elements in Tephritid Species

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1339-1347
Author(s):  
Alfred M Handler ◽  
Sheilachu P Gomez
Keyword(s):  
Drosophila Melanogaster ◽  
Ceratitis Capitata ◽  
Bactrocera Dorsalis ◽  
Parsimony Analysis ◽  
Wild Type ◽  
Anastrepha Suspensa ◽  
Tephritid Species ◽  
Mutant Strains ◽  
Almost All ◽  
Horizontal Transfers

Abstract Function of the Drosophila melanogaster hobo transposon in tephritid species was tested in transient embryonic excision assays. Wild-type and mutant strains of Anastrepha suspensa, Bactrocera dorsalis, B. cucurbitae, Ceratitis capitata, and Toxotrypana curvicauda all supported hobo excision or deletion both in the presence and absence of co-injected hobo transposase, indicating a permissive state for hobo mobility and the existence of endogenous systems capable of mobilizing hobo. In several strains hobo helper reduced excision. Excision depended on hobo sequences in the indicator plasmid, though almost all excisions were imprecise and the mobilizing systems appear mechanistically different from hobo. hobe-related sequences were identified in all species except T. curvicauda. Parsimony analysis yielded a subgroup including the B. cucurbitae and C. capitata sequences along with hobo and Hermes, and a separate, more divergent subgroup including the A. suspensa and B. dorsalis sequences. All of the sequences exist as multiple genomic elements, and a deleted form of the B. cucurbitae element exists in B. dorsalis. The hobo-related sequences are probably members of the hAT transposon family with some evolving from distant ancestor elements, while others may have originated from more recent horizontal transfers.

scholarly journals Blocks in the pseudouridimycin pathway unlock hidden metabolites in the Streptomyces producer strain

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marianna Iorio ◽  
Sahar Davatgarbenam ◽  
Stefania Serina ◽  
Paolo Criscenzo ◽  
Mitja M. Zdouc ◽  
...  
Keyword(s):  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Systematic Investigation ◽  
Biosynthetic Gene ◽  
Wild Type ◽  
Bacterial Rna ◽  
Soil Isolate ◽  
Mutant Strains ◽  
In The Wild ◽  
Polymerase Inhibitor

AbstractWe report a metabolomic analysis of Streptomyces sp. ID38640, a soil isolate that produces the bacterial RNA polymerase inhibitor pseudouridimycin. The analysis was performed on the wild type, on three newly constructed and seven previously reported mutant strains disabled in different genes required for pseudouridimycin biosynthesis. The results indicate that Streptomyces sp. ID38640 is able to produce, in addition to lydicamycins and deferroxiamines, as previously reported, also the lassopeptide ulleungdin, the non-ribosomal peptide antipain and the osmoprotectant ectoine. The corresponding biosynthetic gene clusters were readily identified in the strain genome. We also detected the known compound pyridindolol, for which we propose a previously unreported biosynthetic gene cluster, as well as three families of unknown metabolites. Remarkably, the levels of most metabolites varied strongly in the different mutant strains, an observation that enabled detection of metabolites unnoticed in the wild type. Systematic investigation of the accumulated metabolites in the ten different pum mutants identified shed further light on pseudouridimycin biosynthesis. We also show that several Streptomyces strains, able to produce pseudouridimycin, have distinct genetic relationship and metabolic profile with ID38640.

scholarly journals Mammalian expression of virus-like particles as a proof of principle for next generation polio vaccines

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammad W. Bahar ◽  
Claudine Porta ◽  
Helen Fox ◽  
Andrew J. Macadam ◽  
Elizabeth E. Fry ◽  
...  
Keyword(s):  
Significant Risk ◽  
Next Generation ◽  
Wild Type ◽  
Inactivated Polio Vaccine ◽  
Vaccination Programs ◽  
Virus Like Particles ◽  
Mammalian Expression ◽  
Cryo Electron Microscopy ◽  
Alternative Expression ◽  
Antibody Titres

AbstractGlobal vaccination programs using live-attenuated oral and inactivated polio vaccine (OPV and IPV) have almost eradicated poliovirus (PV) but these vaccines or their production pose significant risk in a polio-free world. Recombinant PV virus-like particles (VLPs), lacking the viral genome, represent safe next-generation vaccines, however their production requires optimisation. Here we present an efficient mammalian expression strategy producing good yields of wild-type PV VLPs for all three serotypes and a thermostabilised variant for PV3. Whilst the wild-type VLPs were predominantly in the non-native C-antigenic form, the thermostabilised PV3 VLPs adopted the native D-antigenic conformation eliciting neutralising antibody titres equivalent to the current IPV and were indistinguishable from natural empty particles by cryo-electron microscopy with a similar stabilising lipidic pocket-factor in the VP1 β-barrel. This factor may not be available in alternative expression systems, which may require synthetic pocket-binding factors. VLPs equivalent to these mammalian expressed thermostabilized particles, represent safer non-infectious vaccine candidates for the post-eradication era.

scholarly journals N-3-Hydroxy Dodecanoyl-DL-homoserine Lactone (OH-dDHL) Triggers Apoptosis of Bone Marrow-Derived Macrophages through the ER- and Mitochondria-Mediated Pathways

2021 ◽  
Vol 22 (14) ◽  
pp. 7565
Author(s):  
Kyungho Woo ◽  
Dong Ho Kim ◽  
Man Hwan Oh ◽  
Ho Sung Park ◽  
Chul Hee Choi
Keyword(s):  
Bone Marrow ◽  
Quorum Sensing ◽  
Deletion Mutant ◽  
Transmembrane Protein ◽  
Cell Communication ◽  
Homoserine Lactone ◽  
Host Responses ◽  
Wild Type ◽  
Mutant Strains

Quorum sensing of Acinetobacter nosocomialis for cell-to-cell communication produces N-3-hydroxy dodecanoyl-DL-homoserine lactone (OH-dDHL) by an AnoR/I two-component system. However, OH-dDHL-driven apoptotic mechanisms in hosts have not been clearly defined. Here, we investigated the induction of apoptosis signaling pathways in bone marrow-derived macrophages treated with synthetic OH-dDHL. Moreover, the quorum-sensing system for virulence regulation was evaluated in vivo using wild-type and anoI-deletion mutant strains. OH-dDHL decreased the viability of macrophage and epithelial cells in dose- and time-dependent manners. OH-dDHL induced Ca2+ efflux and caspase-12 activation by ER stress transmembrane protein (IRE1 and ATF6a p50) aggregation and induced mitochondrial dysfunction through reactive oxygen species (ROS) production, which caused cytochrome c to leak. Pretreatment with a pan-caspase inhibitor reduced caspase-3, -8, and -9, which were activated by OH-dDHL. Pro-inflammatory cytokine and paraoxonase-2 (PON2) gene expression were increased by OH-dDHL. We showed that the anoI-deletion mutant strains have less intracellular invasion compared to the wild-type strain, and their virulence, such as colonization and dissemination, was decreased in vivo. Consequently, these findings revealed that OH-dDHL, as a virulence factor, contributes to bacterial infection and survival as well as the modification of host responses in the early stages of infection.

scholarly journals act Operon Control of Developmental Gene Expression in Myxococcus xanthus

2002 ◽  
Vol 184 (4) ◽  
pp. 1172-1179 ◽  
Author(s):  
Thomas M. A. Gronewold ◽  
Dale Kaiser
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
The Other ◽  
Loss Of Function ◽  
Wild Type ◽  
Developmental Gene ◽  
Developmental Gene Expression ◽  
Mutant Strains ◽  
Genes Encoding ◽  
Signal Production

ABSTRACT Cell-bound C-signal guides the building of a fruiting body and triggers the differentiation of myxospores. Earlier work has shown that transcription of the csgA gene, which encodes the C-signal, is directed by four genes of the act operon. To see how expression of the genes encoding components of the aggregation and sporulation processes depends on C-signaling, mutants with loss-of-function mutations in each of the act genes were investigated. These mutations were found to have no effect on genes that are normally expressed up to 3 h into development and are C-signal independent. Neither the time of first expression nor the rate of expression increase was changed in actA, actB, actC, or actD mutant strains. Also, there was no effect on A-signal production, which normally starts before 3 h. By contrast, the null act mutants have striking defects in C-signal production. These mutations changed the expression of four gene reporters that are related to aggregation and sporulation and are expressed at 6 h or later in development. The actA and actB null mutations substantially decreased the expression of all these reporters. The other act null mutations caused either premature expression to wild-type levels (actC) or delayed expression (actD), which ultimately rose to wild-type levels. The pattern of effects on these reporters shows how the C-signal differentially regulates the steps that together build a fruiting body and differentiate spores within it.

scholarly journals Behavior of a Wild-Type and Two Mutant Strains of Colletotrichum gloeosporioides f. sp. aeschynomene on Northern Jointvetch in the Field

Plant Disease ◽  
1998 ◽  
Vol 82 (4) ◽  
pp. 374-379 ◽  
Author(s):  
Y. Luo ◽  
D. O. TeBeest
Keyword(s):  
Population Density ◽  
Wild Type Strain ◽  
Colletotrichum Gloeosporioides ◽  
Biological Control Agent ◽  
Field Tests ◽  
The United States ◽  
Control Agent ◽  
Sampling Time ◽  
Wild Type ◽  
Mutant Strains

The fungus Colletotrichum gloeosporioides f. sp. aeschynomene causes an anthracnose on Aeschynomene virginica and has been used as a biological control agent to control this weed in the United States. The population dynamics of a wild-type strain (3-1-3) and two mutant strains of 3-1-3 of C. gloeosporioides f. sp. aeschynomene, a benomyl-resistant strain (B21) and nitrate-nonutilizing strain (Nit A), were studied in field tests on northern jointvetch in 1994 and 1995 to determine how the strains interacted on infected plants under field conditions. Plants were co-inoculated with strains 3-1-3 and B21, strains 3-1-3 and Nit A, and strains 3-1-3, B21, and Nit A at equal and unequal initial proportions. Plants were grown and maintained under flooded conditions in small wading pools. In co-inoculation of plants with 3-1-3 and B21 from equal initial proportions, the population of 3-1-3 increased slightly until it reached a proportion of 60 to 70%, whereas the population density of B21 reached 30 to 40% at the end of growing season. From unequal initial proportions, the population density of B21 decreased from 90 to about 50%, whereas the 3-1-3 increased from 10 to 50%. The population density of 3-1-3 increased from an equal initial proportion and was significantly greater than that of Nit A on every sampling time. From unequal initial proportions, the population density of 3-1-3 increased from 10 to 90%, whereas that of Nit A declined. In co-inoculation of plants with the three strains, the population density of 3-1-3 was significantly greater than those of the mutant strains at every sampling time. The proportions of mutant strains within the total population of C. gloeosporioides f. sp. aeschynomene on plants varied according to the test conditions and the number and types of strains co-inoculated.

Antibacterial effect of hyaluronan/chitosan nanofilm in the initial adhesion of Pseudomonas aeruginosa wild type, and IV pili and LPS mutant strains

2021 ◽  
pp. 101415
Author(s):  
Jacobo Hernandez-Montelongo ◽  
Gianlucca G. Nicastro ◽  
Thays de O. Pereira ◽  
Mariana Zavarize ◽  
Marisa M. Beppu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Effect ◽  
Wild Type ◽  
Initial Adhesion ◽  
Mutant Strains

scholarly journals Phenotypic and Genetic Analysis of “Chameleon,” a Paramecium Mutant With an Enhanced Sensitivity to Magnesium

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 871-880
Author(s):  
Robin R Preston ◽  
Jocelyn A Hammond
Keyword(s):  
Genetic Analysis ◽  
Single Locus ◽  
Behavioral Analysis ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Ion Conductance ◽  
Membrane Excitation ◽  
Enhanced Sensitivity ◽  
Electrophysiological Analysis ◽  
Mutant Strains

Three mutant strains of Paramecium tetraurelia with an enhanced sensitivity to magnesium have been isolated. These new “Chameleon” mutants result from partial- or codominant mutations at a single locus, Cha. Whereas the wild type responded to 5 mm Mg2+ by swimming backward for 10–15 sec, Cha mutants responded with ∼30 sec backward swimming. Electrophysiological analysis suggested that this behavior may be caused by slowing in the rate at which a Mg2+-specific ion conductance deactivates following membrane excitation. This would be consistent with an observed increase in the sensitivity of Cha mutants to nickel poisoning, since Ni2+ is also able to enter the cell via this pathway. More extensive behavioral analysis showed that Cha cells also overresponded to Na+, but there was no evidence for a defect in intracellular Ca2+ homeostasis that might account for a simultaneous enhancement of both the Mg2+ and Na+ conductances. The possibility that the Cha locus may encode a specific regulator of the Mg2+- and Na+-permeabilities is considered.

scholarly journals Roles of rpoN, fliA,and flgR in Expression of Flagella inCampylobacter jejuni

2001 ◽  
Vol 183 (9) ◽  
pp. 2937-2942 ◽  
Author(s):  
Aparna Jagannathan ◽  
Chrystala Constantinidou ◽  
Charles W. Penn
Keyword(s):  
Campylobacter Jejuni ◽  
Genome Sequence ◽  
Sigma Factor ◽  
Transcriptional Activator ◽  
Alternative Sigma Factor ◽  
Wild Type ◽  
Electron Microscopic ◽  
Global Regulation ◽  
Mutant Strains ◽  
Microscopic Studies

ABSTRACT Three potential regulators of flagellar expression present in the genome sequence of Campylobacter jejuni NCTC 11168, the genes rpoN, flgR, andfliA, which encode the alternative sigma factor ς54, the ς54-associated transcriptional activator FlgR, and the flagellar sigma factor ς28, respectively, were investigated for their role in global regulation of flagellar expression. The three genes were insertionally inactivated inC. jejuni strains NCTC 11168 and NCTC 11828. Electron microscopic studies of the wild-type and mutant strains showed that therpoN and flgR mutants were nonflagellate and that the fliA mutant had truncated flagella. Immunoblotting experiments with the three mutants confirmed the roles of rpoN, flgR, and fliA in the expression of flagellin.

Sign in / Sign up

Export Citation Format

Share Document