| phylogenetic affiliation of bev, a bacterial parasite of the leafhopper euscelidius variegatus, on the basis of 16s rdna sequences. | the phylogenetic relationship of a nonflagellated, gram-negative, rod-shaped intracellular bacterial parasite (bev) of the leafhopper euscelidius variegatus to other bacteria within the class proteobacteria was determined by sequence analysis of 16s rdnas. the presence of specific signature nucleotides showed this bacterium to be a member of the gamma-3 subdivision of the proteobacteria. phylogenetic analysis based on maximum parsimony placed bev within a clade in the enterobacteriaceae, which i ... | 1993 | 7763405 |
| detection of phytoplasma by polymerase chain reaction of insect feeding medium and its use in determining vectoring ability. | a polymerase chain reaction (pcr)-based method was developed for the detection of phytoplasma in insect feeding medium (sucrose). a correlation was established between the transmissibility of flavescence dorée phytoplasma in the experimental leafhopper vector euscelidius variegatus and its detection by pcr in the insect feeding medium. however, phytoplasma were detected in the insects' bodies 3 weeks before they began to transmit. hence, pcr assays of the sucrose medium reflected phytoplasma vec ... | 2001 | 18944030 |
| the major antigenic membrane protein of "candidatus phytoplasma asteris" selectively interacts with atp synthase and actin of leafhopper vectors. | phytoplasmas, uncultivable phloem-limited phytopathogenic wall-less bacteria, represent a major threat to agriculture worldwide. they are transmitted in a persistent, propagative manner by phloem-sucking hemipteran insects. phytoplasma membrane proteins are in direct contact with hosts and are presumably involved in determining vector specificity. such a role has been proposed for phytoplasma transmembrane proteins encoded by circular extrachromosomal elements, at least one of which is a plasmid ... | 2011 | 21799902 |
| host plant determines the phytoplasma transmission competence of empoasca decipiens (hemiptera: cicadellidae). | phytoplasmas are phloem-restricted plant pathogens transmitted by leafhoppers, planthoppers, and psyllids (hemiptera). most known phytoplasma vectors belong to the cicadellidae, but many are still unknown. within this family, empoasca spp. (typhlocybinae) have tested positive for the presence of some phytoplasmas, and phytoplasma transmission has been proven for one species. the aim of this work was to investigate the ability of empoasca decipiens paoli in transmitting chrysanthemum yellows phyt ... | 2011 | 21510180 |
| origin and examination of a leafhopper facultative endosymbiont. | eukaryotes engage in intimate interactions with microbes that range in age and type of association. although many conspicuous examples of ancient insect associates are studied (e.g., buchnera aphidicola), fewer examples of younger associations are known. here, we further characterize a recently evolved bacterial endosymbiont of the leafhopper euscelidius variegatus (hemiptera, cicadellidae), called bev. we found that bev, continuously maintained in e. variegatus hosts at uc berkeley since 1984, ... | 2011 | 21336565 |
| oligonucleotides as hybridization probes to localize phytoplasmas in host plants and insect vectors. | abstract protocols have been developed using 20- to 24-mer oligodeoxynucleotides, originally designed as polymerase chain reaction primers, as hybridization probes for the nonradioactive detection of italian clover phyllody (icph) phytoplasma in plant (chrysanthemum carinatum) and leafhopper (euscelidius variegatus) tissue. in situ hybridization of paraffin-embedded tissue sections was carried out using oligodeoxynucleotides 5' end-labeled with either cy5 fluorochrome, biotin, or digoxigenin. th ... | 1999 | 18944732 |
| insect injection and artificial feeding bioassays to test the vector specificity of flavescence dorée phytoplasma. | abstract the specificity of vector transmission of flavescence dorée phytoplasma (fdp) was tested by injecting fdp, extracted from laboratory-reared infective euscelidius variegatus, into specimens of 15 other hemipteran insect species collected in european vineyards. concentrations of viable phytoplasma extracts and latency in vectors were monitored by injection of healthy-reared e. variegatus leafhoppers. based on these preliminary results, insects were injected by using phytoplasma extracts t ... | 2006 | 18943154 |
| characterization of putative membrane protein genes of the 'candidatus phytoplasma asteris', chrysanthemum yellows isolate. | to characterize potentially important surface-exposed proteins of the phytoplasma causing chrysanthemum yellows (cy), new primers were designed based on the conserved regions of 3 membrane protein genes of the completely sequenced onion yellows and aster yellows witches' broom phytoplasmas and were used to amplify cy dna. the cy genes secy, amp, and arti, encoding the protein translocase subunit secy, the antigenic membrane protein amp and the arginine transporter arti, respectively, were cloned ... | 2008 | 18449218 |
| interrelationships between "candidatus phytoplasma asteris" and its leafhopper vectors (homoptera: cicadellidae). | the titer of chrysanthemum yellows phytoplasma (cyp, "candidatus phytoplasma asteris") in the three vector species euscelis incisus kirschbaum, euscelidius variegatus kirschbaum, and macrosteles quadripunctulatus kirschbaum (homoptera: cicadellidae) was measured after controlled acquisition from infected chrysanthemum carinatum (schousboe) (daisy) plants. phytoplasma dna was quantified in relation to insect dna (genome units [gu] of phytoplasma dna per ng of insect dna) by using a quantitative r ... | 2007 | 17972626 |
| effect of two strains of flavescence dorée phytoplasma on the survival and fecundity of the experimental leafhopper vector euscelidius variegatus kirschbaum. | we have investigated the influence on longevity and fecundity of flavescence dorée phytoplasma (fdp), the agent of a grapevine yellows disease, in the experimental vector euscelidius variegatus kirschbaum. late instar nymphs were exposed to one or the other of two strains of fdp (fd92 and fd2000) by feeding on infected broad bean (vicia faba l.) or on healthy broad bean or maize (zea mays l.) for an acquisition access period of 13 days. detection of fdp in individual insects was done with pcr as ... | 2005 | 16087002 |
| phylogenetic characterization of two transovarially transmitted endosymbionts of the bedbug cimex lectularius (heteroptera:cimicidae). | two different inherited bacterial symbionts from ovary tissue of the bedbug cimex lectularius were characterized by gene amplification and sequencing analysis of their 16s rdna gene. the first bacterium belongs to the wolbachia subgroup of the alpha-proteobacteria, the second is a member of the gamma-subdivision, and is closely related to the bacterial parasite of the leafhopper euscelidius variegatus (bev) which was shown to be capable of transovarial transmission. the high similarity (> 97%) b ... | 1997 | 9272448 |
| immunolabeling of grapevine flavescence dorée mlo in salivary glands of euscelidius variegatus: a light and electron microscopy study. | flavescence dorée (fd), a grapevine yellows disease, is caused by a mycoplasma-like organism (mlo). a colloidal gold indirect immunolabeling technique identified mlo in salivary glands of a vector leafhopper, euscelidius variegatus. after aldehyde fixation, tissue samples were prepared by cryoultramicrotomy or embedding in acrylic resins. double fixation with aldehydes and osmium retroxide, followed by embedding in epon, was also performed. thin or semi-thin serial sections were treated with pol ... | 1990 | 2294149 |
| transmission via plants of an insect pathogenic bacterium that does not multiply or move in plants. | a bacterial parasite (designated as bev) of the leafhopper euscelidius variegatus, which is passed transovarially to offspring, was transmitted from insect to insect via feeding of the insects in plants. the rate of bacterial infection of leafhoppers fed upon plants that had previously been exposed to bev-infected leafhoppers declined with an increase in the time that infected leafhoppers had been off rye grass. transmission of bev also occurred on sugar beet and barley but not celery. the bacte ... | 1994 | 24190165 |
| [oscillation in the energy metabolism of the insect host and symbiont. ii. analysis of possible endogenous rhythms in both systems]. | the insect group which includes cicadas harbours intracellular bacterial symbionts (endocytobionts) which are passed on from generation to generation in the form of a symbiont ball inserted between the egg membrane and the rear pole of the egg cell. bioluminiescence methods can be used to measure the oscillations in atp, adp and amp levels in egg systems which have been separated into a host and a symbiont egg part (euscelidius variegatus), and which are exposed to constant light at 26 degrees c ... | 1980 | 7428440 |
| role of the major antigenic membrane protein in phytoplasma transmission by two insect vector species. | phytoplasmas are bacterial plant pathogens (class mollicutes), transmitted by phloem feeding leafhoppers, planthoppers and psyllids in a persistent/propagative manner. transmission of phytoplasmas is under the control of behavioral, environmental and geographical factors, but molecular interactions between membrane proteins of phytoplasma and vectors may also be involved. the aim of the work was to provide experimental evidence that in vivo interaction between phytoplasma antigenic membrane prot ... | 2015 | 26424332 |
| horizontal transmission of intracellular insect symbionts via plants. | experimental evidence is accumulating that endosymbionts of phytophagous insects may transmit horizontally via plants. intracellular symbionts known for manipulating insect reproduction and altering fitness (rickettsia, cardinium, wolbachia, and bacterial parasite of the leafhopper euscelidius variegatus) have been found to travel from infected insects into plants. other insects, either of the same or different species can acquire the symbiont from the plant through feeding, and in some cases tr ... | 2017 | 29234308 |
| aquaporin-related proteins in the filter chamber of homopteran insects. | in the homopteran order of insects, the plant xylem feeders exhibit a highly differentiated part of their digestive tract known as the filter chamber. in this tissue, water crosses plasma membranes through a transepithelial osmotic gradient. in previous studies on the filter chamber of cicadella viridis, we purified and characterized from the plasma membranes a 25 kda protein that we demonstrated to be an aquaporin (or water channel, member of the major intrinsic protein family, a group of membr ... | 1997 | 9377634 |
| genome sequence, prevalence and quantification of the first iflavirus identified in a phytoplasma insect vector. | the leafhopper euscelidius variegatus is a natural vector of chrysanthemum yellows phytoplasma (cy) and an efficient vector of flavescence dorée phytoplasma (fd) under laboratory conditions. during a transcriptome sequencing (rna-seq) project aimed at investigating the interactions between the insect and the two phytoplasmas, a 10,616-nucleotide-long contig with high sequence similarity to known picorna-like viruses was identified among the assembled insect transcripts. the discovery came totall ... | 2017 | 27888410 |
| [oscillations in the energy metabolism of the host and symbiont of a cicada. i. analysis of possible metabolic and physiologic correlations of both systems]. | the insect group which includes cicadas harbours intracellular bacterial symbionts which are passed on from generation to generation in the form of a 'symbiont ball' inserted between the egg membrane and the rear pole of the egg cell. bioluminiscence methods can be used to measure the oscillations in atp, adp and amp levels in egg systems which have been separated into a host and a symbiont part (euscelidius variegatus, euscelis incisus), and which are exposed to constant light or light-dark var ... | 1979 | 118849 |
| [on the ultrastructure of the filter chamber of the leafhopper euscelidius variegatus kbm. (jassidae)]. | | 1968 | 5706756 |
| decreasing global transcript levels over time suggest that phytoplasma cells enter stationary phase during plant and insect colonization. | to highlight different transcriptional behaviors of the phytoplasma in the plant and animal host, expression of 14 genes of "candidatus phytoplasma asteris," chrysanthemum yellows strain, was investigated at different times following the infection of a plant host (arabidopsis thaliana) and two insect vector species (macrosteles quadripunctulatus and euscelidius variegatus). target genes were selected among those encoding antigenic membrane proteins, membrane transporters, secreted proteins, and ... | 2015 | 25636844 |
| a tritrophic signal that attracts parasitoids to host-damaged plants withstands disruption by non-host herbivores. | volatiles emitted by herbivore-infested plants are highly attractive to parasitoids and therefore have been proposed to be part of an indirect plant defense strategy. however, this proposed function of the plant-provided signals remains controversial, and it is unclear how specific and reliable the signals are under natural conditions with simultaneous feeding by multiple herbivores. phloem feeders in particular are assumed to interfere with plant defense responses. therefore, we investigated ho ... | 2010 | 21078181 |
| bacterial associates of hyalesthes obsoletus (hemiptera: cixiidae), the insect vector of bois noir disease, with a focus on cultivable bacteria. | the planthopper hyalesthes obsoletus (hemiptera: cixiidae) is an important vector of phytoplasma diseases in grapevine. in the current study, the bacterial community compositions of symbionts of this insect were examined. two dominant bacterial lineages were identified by mass sequencing: the obligate symbiont candidatus sulcia, and a facultative symbiont that is closely related to pectobacterium sp. and to bev, a cultivable symbiont of another phytoplasma vector, the leafhopper euscelidius vari ... | 2017 | 27602526 |
| selection of reference genes from two leafhopper species challenged by phytoplasma infection, for gene expression studies by rt-qpcr. | phytoplasmas are phloem-limited phytopathogenic wall-less bacteria and represent a major threat to agriculture worldwide. they are transmitted in a persistent, propagative manner by phloem-sucking hemipteran insects. for gene expression studies based on mrna quantification by rt-qpcr, stability of housekeeping genes is crucial. the aim of this study was the identification of reference genes to study the effect of phytoplasma infection on gene expression of two leafhopper vector species. the iden ... | 2013 | 24119747 |