Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| codon usage bias and trna over-expression in buchnera aphidicola after aromatic amino acid nutritional stress on its host acyrthosiphon pisum. | codon usage bias and relative abundances of trna isoacceptors were analysed in the obligate intracellular symbiotic bacterium, buchnera aphidicola from the aphid acyrthosiphon pisum, using a dedicated 35mer oligonucleotide microarray. buchnera is archetypal of organisms living with minimal metabolic requirements and presents a reduced genome with high-evolutionary rate. codonusage in buchnera has been overcome by the high mutational bias towards at bases. however, several lines of evidence for c ... | 2006 | 16963497 |
| cytochrome c oxidase mrna as an internal control for detection of potato virus y and potato leafroll virus from single aphids by a co-amplification rt-pcr assay. | using cytochrome c oxidase subunit 1 (cox1) mrna as the internal control, a triplex reverse transcription-polymerase chain reaction (rt-pcr) for detection of potato virus y (pvy) and potato leafroll virus (plrv) with co-amplification of cox1 from single specimens of various aphid species has been developed. partial length cdna of cox1 from green peach aphid, myzus persicae (sulzer), potato aphid, macrosiphum euphorbiae (thomas), buckthorn aphid, aphis nasturtii (kaltenbach), and pea aphid, acyrt ... | 2006 | 17010449 |
| covariance of phenotypically plastic traits induces an adaptive shift in host selection behaviour. | flexibility in adult body size allows generalist parasitoids to use many host species at a cost of producing a range of adult sizes. consequently, host selection behaviour must also maintain a level of flexibility as adult size is related to capture efficiency. in the present study, we investigated covariance of two plastic traits--size at pupation and host size selection behaviour-using aphidius ervi reared on either acyrthosiphon pisum or aulacorthum solani, generating females of disparate siz ... | 2006 | 17015365 |
| temporal habitat variability and the maintenance of sex in host populations of the pea aphid. | the evolutionary maintenance of sex, despite competition from asexual reproduction, has long intrigued the evolutionary biologists owing to its numerous apparent short-term costs. in aphids, winter climate is expected to determine the maintenance of sexual lineages in the high latitude zones owing to their exclusive ability to produce frost-resistant eggs. however, diverse reproductive modes may coexist at a local scale where climatic influence is counteracted by microgeographical factors. in th ... | 2006 | 17015368 |
| population differentiation and genetic variation in host choice among pea aphids from eight host plant genera. | habitat choice plays a critical role in the processes of host range evolution, specialization, and ecological speciation. pea aphid, acyrthosiphon pisum, populations from alfalfa and red clover in eastern north america are known to be genetically differentiated and show genetic preferences for the appropriate host plant. this species feeds on many more hosts, and here we report a study of the genetic variation in host plant preference within and between pea aphid populations collected from eight ... | 2006 | 17017058 |
| predator avoidance behavior in the pea aphid: costs, frequency, and population consequences. | induced prey defenses can be costly. these costs have the potential to reduce prey survival or reproduction and, therefore, prey population growth. i estimated the potential for predators to suppress populations of pea aphids (acyrthosiphon pisum) in alfalfa fields through the induction of pea aphid predator avoidance behavior. i quantified (1) the period of non-feeding activity that follows a disturbance event, (2) the effect of frequent disturbance on aphid reproduction, and (3) the frequency ... | 2007 | 17066305 |
| role of host nutrition in symbiont regulation: impact of dietary nitrogen on proliferation of obligate and facultative bacterial endosymbionts of the pea aphid acyrthosiphon pisum. | the impact of host nutrition on symbiont regulation in the pea aphid acyrthosiphon pisum was investigated. the population density of the obligate symbiont buchnera aphidicola positively correlated with dietary nitrogen levels. in contrast, the population density of the facultative symbiont serratia symbiotica increased in aphids reared on low-nitrogen diets, indicating distinct regulatory mechanisms in the same insect host. | 2007 | 17158610 |
| characterization of a membrane-bound aminopeptidase purified from acyrthosiphon pisum midgut cells. a major binding site for toxic mannose lectins. | a single membrane-bound aminopeptidase n (apn) occurs in the pea aphid (acyrthosiphon pisum harris) midgut, with a ph optimum of 7.0, pi of 8.1 and molecular mass of 130 kda. this enzyme accounts for more than 15.6% of the total gut proteins. after being solubilized in detergent, apn was purified to homogeneity. the enzyme is a glycoprotein rich in mannose residues, which binds the entomotoxic lectins of the concanavalin family. the internal sequence of apn is homologous with a conservative doma ... | 2006 | 17212776 |
| aphidbase: a database for aphid genomic resources. | aphidbase aims to (i) store recently acquired genomic resources on aphids and (ii) compare them to other insect resources as functional annotation tools. for that, the drosophila melanogaster genome has been loaded in the database using the gmod open source software for a comparison with the 17 069 pea aphid unique transcripts (contigs) and the 13 639 gene transcripts of the anopheles gambiae. links to flybase and a.gambiae entrez databases allow a rapid characterization of the putative function ... | 2007 | 17237053 |
| synthesis, insecticidal activity, and qsar of novel nitromethylene neonicotinoids with tetrahydropyridine fixed cis configuration and exo-ring ether modification. | to keep the nitro group in the cis position, a series of nitromethylene neonicotinoids containing a tetrahydropyridine ring with exo-ring ether modifications were designed and synthesized. all of the compounds were characterized and confirmed by 1h nmr, high-resolution mass spectroscopy, elemental analysis, and ir. the bioassay tests showed that some of them exhibited good insecticidal activities against pea aphids. on the basis of 10 nitromethylene derivatives, the quantitative structure-bioact ... | 2007 | 17311404 |
| selective elimination of aphid endosymbionts: effects of antibiotic dose and host genotype, and fitness consequences. | multiple endosymbionts commonly coexist in the same host insects. in order to gain an understanding of the biological roles of the individual symbionts in such complex systems, experimental techniques for enabling the selective removal of a specific symbiont from the host are of great importance. by using the pea aphid-buchnera-serratia endosymbiotic system as a model, the efficacy, generality, and fitness consequences of selective elimination techniques at various antibiotic doses and under a v ... | 2007 | 17313660 |
| apvasa marks germ-cell migration in the parthenogenetic pea aphid acyrthosiphon pisum (hemiptera: aphidoidea). | in the parthenogenetic and viviparous pea aphid acyrthosiphon pisum, germline specification depends on the germ plasm localized to the posterior region of the egg chamber before the formation of the blastoderm. during blastulation, germline segregation occurs at the egg posterior, and in early gastrulation germ cells are pushed inward by the invaginating germ band. previous studies suggest that germ cells remain dorsal in the embryo in subsequent developmental stages. in fact, though, it is not ... | 2007 | 17333259 |
| molecular characterisation of a candidate gut sucrase in the pea aphid, acyrthosiphon pisum. | the hydrolysis of sucrose, the principal dietary source of carbon for aphids, is catalysed by a gut alpha-glucosidase/transglucosidase activity. an alpha-glucosidase, referred to as aps1, was identified in both a gut-specific cdna library and a sucrase-enriched membrane preparation from guts of the pea aphid acyrthosiphon pisum by a combination of genomic and proteomic techniques. aps1 contains a predicted signal peptide, and has a predicted molecular mass of 68 kda (unprocessed) or 66.4 kda (ma ... | 2007 | 17368194 |
| inter- and intra-guild interactions related to aphids in nettle (urtica dioica l.) strips closed to field crops. | a field experiment designed to assess the biodiversity related to nettle strips closed to crops, and more particularly the aphid and related beneficial populations, was established in experimental farm located in gembloux (belgium). margin strips of nettle (urtica dioica) closed to wheat (triticum aestivum), green pea (pisum sativum) and rape (brassicae napus) fields were investigated. the diversity, abundance of aphids and related predators were analysed according to the plant crop species and ... | 2006 | 17385508 |
| genetic variation in the effect of a facultative symbiont on host-plant use by pea aphids. | ecological specialisation on different host plants occurs frequently among phytophagous insects and is normally assumed to have a genetic basis. however, insects often carry microbial symbionts, which may play a role in the evolution of specialisation. the bacterium regiella insecticola is a facultative symbiont of pea aphids (acyrthosiphon pisum) where it is found most frequently in aphid clones feeding on trifolium giving rise to the hypothesis that it may improve aphid performance on this pla ... | 2007 | 17415589 |
| ecdysteroids from serratula wolffii roots. | two new natural ecdysteroids, 20,22-didehydrotaxisterone (1) and 1-hydroxy-20,22-didehydrotaxisterone (2), were isolated from the roots of serratula wolffii. their structures were elucidated by 1d and 2d nmr spectroscopy and mass spectrometry. the biological activities of these compounds were determined via oral aphid (acyrthosiphon pisum (harris)) tests. compound 1 was inactive and compound 2 exhibited very low toxicity in the oral aphid test. the activities of these two ecdysteroids were in ag ... | 2007 | 17417908 |
| aphid thermal tolerance is governed by a point mutation in bacterial symbionts. | symbiosis is a ubiquitous phenomenon generating biological complexity, affecting adaptation, and expanding ecological capabilities. however, symbionts, which can be subject to genetic limitations such as clonality and genomic degradation, also impose constraints on hosts. a model of obligate symbiosis is that between aphids and the bacterium buchnera aphidicola, which supplies essential nutrients. we report a mutation in buchnera of the aphid acyrthosiphon pisum that recurs in laboratory lines a ... | 2007 | 17425405 |
| a gamma-glutamyl transpeptidase of aphidius ervi venom induces apoptosis in the ovaries of host aphids. | parasitism by the endophagous braconid aphidius ervi (hymenoptera, braconidae) has a negative impact on the reproductive activity of its host, acyrthosiphon pisum (homoptera, aphididae). the host castration is induced by the parasitoid venom and is reproduced by the injection of chromatographic fractions highly enriched with two proteins, of 18 (p18) and 36 kda (p36) in size, respectively. here we demonstrate that these bioactive proteins trigger apoptosis of the cells in the germaria and ovario ... | 2007 | 17456440 |
| deterrence and toxicity of plant saponins for the pea aphid acyrthosiphon pisum harris. | plant saponins are widely distributed among plants and have a wide range of biological properties. three alfalfa saponins - zanhic acid tridesmoside, 3glca, 28ararhaxyl medicagenic acid glycoside, and 3glca, 28ararha medicagenic acid glycoside - were tested for their settling inhibition effects on feeding behavior of the aphid acyrthosiphon pisum using the electrical penetration graph method. application of saponins to artificial diets affected the insects' probing behavior. in general, saponins ... | 2007 | 17610116 |
| comparison of radioimmunoassay and liquid chromatography tandem mass spectrometry for determination of juvenile hormone titers. | this paper compares the results of juvenile hormone (jh) titer determinations in two insect species, melanoplus sanguinipes, a migratory grasshopper, and acyrthosiphon pisum, the pea aphid, using a chiral-specific jh radioimmunoassay (ria) and liquid chromatography tandem mass spectrometry (lc-ms/ms), after extraction of jh with either hexane or isooctane-methanol. we compared results of jh titer determinations done on extracts of m. sanguinipes hemolymph taken from animals flown to exhaustion i ... | 2007 | 17628278 |
| antibiotics, primary symbionts and wing polyphenism in three aphid species. | the possible role of the primary buchnera symbionts in wing polyphenism is examined in three aphid species. presumptive winged aphids were fed on antibiotic-treated beans to destroy these symbionts. as previously reported, this leads to inhibited growth and low/zero fecundity. when such treatment is applied to the short-day-induced gynoparae (the winged autumn migrant) of the black bean aphid, aphis fabae, it also causes many insects to develop as wingless or winged/wingless intermediate adult f ... | 2007 | 17628287 |
| common genome-wide patterns of transcript accumulation underlying the wing polyphenism and polymorphism in the pea aphid (acyrthosiphon pisum). | the pea aphid, acyrthosiphon pisum, exhibits several environmentally cued polyphenisms, in which discrete, alternative phenotypes are produced. at low-density, parthenogenetic females produce unwinged female progeny, but at high-density females produce progeny that develop with wings. these alternative phenotypes represent a solution to the competing demands of dispersal and reproduction. males also develop as either winged or unwinged, but these alternatives are determined by a genetic polymorp ... | 2015 | 17651358 |
| cross-species transferability of microsatellite markers from six aphid (hemiptera: aphididae) species and their use for evaluating biotypic diversity in two cereal aphids. | the abundance and distribution of microsatellites, or simple sequence repeats (ssrs) were explored in the expressed sequence tag (est) and genomic sequences of the pea aphid, acyrthosiphon pisum (harris), and the green peach aphid, myzus persicae (sulzer). a total of 108 newly developed, together with 40 published, ssr markers were investigated for their cross-species transferability among six aphid species. genetic diversity among six greenbug, schizaphis graminum (rondani) and two russian whea ... | 2007 | 17714463 |
| the systemic effects of juvenoids on the red firebug pyrrhocoris apterus and on the pea aphid acyrthosiphon pisum with data on life table response. | a series of juvenoid alcohols and their glycosidic derivatives (juvenogens), synthesized at the institute of organic chemistry and biochemistry in prague, commercially used juvenoids and the natural derivatives of juvabione were evaluated for their systemic juvenilizing effect on the red firebug, pyrrhocoris apterus l., and on the pea aphid, acyrthosiphon pisum harris. a life table response experiment was designed, and demographic characteristics were computed for a cohort of a. pisum following ... | 2007 | 17724791 |
| seasonal photoperiodism regulates the expression of cuticular and signalling protein genes in the pea aphid. | seasonal photoperiodism in aphids is responsible for the spectacular switch from asexual to sexual reproduction. however, little is known on the molecular and physiological mechanisms involved in reproductive mode shift through the action of day length. earlier works showed that aphid head, but not eyes, directly perceives the photoperiodic signal through the cuticle. in order to identify genes regulating the photoperiodic response, a 3321 cdna microarray developed for the pea aphid, acyrthosiph ... | 2007 | 17785197 |
| peptidoglycan in the cell wall of the primary intracellular symbiote of the pea aphid. | primary intracellular symbiotes of the pea aphid, acyrthosiphon pisum (harris), when fixed with potassium permanganate, revealed a distinctly staining area between the cytoplasmic membrane and the outer cell-wall envelope. this area is thought to be analogous to the peptidoglycan complex of the eubacteriales. in addition, the diagnostic bacterial peptidoglycan amino compounds, muramic acid and diaminopimelic acid, were detected in a hydrochloric acid hydrolyzate of isolated symbiotes. | 1977 | 17809442 |
| pea aphid: rearing on a chemically defined diet. | pea aphids, acyrthosiphon pisum (harr.), reared for two successive generations on a diet made of 23 amino acids and amides, 11 watersoluble vitamins, 35 percent sucrose, salts, and cholesterol, remained apterous. they grew and developed during the first generation almost as well as those grown on pea plants, with very little mortality. | 1963 | 17835604 |
| gene knockdown by rnai in the pea aphid acyrthosiphon pisum. | rna interference (rnai) is a powerful method to inhibit gene expression in a sequence specific manner. | 2007 | 17903251 |
| strong heterogeneity in nucleotidic composition and codon bias in the pea aphid (acyrthosiphon pisum) shown by est-based coding genome reconstruction. | the aim of this study was to analyze patterns of nucleotidic composition and codon usage in the pea aphid genome (acyrthosiphon pisum). a collection of 60,000 expressed sequence tags (ests) in the pea aphid has been used to automatically reconstruct 5809 coding sequences (cdss), based on similarity with known proteins and on coding style recognition. reconstructions were manually checked for ribosomal proteins, leading to tentatively reconstruct the nea-complete set of this category. pea aphid c ... | 2007 | 17928936 |
| large gene family expansion and variable selective pressures for cathepsin b in aphids. | aphids exclusively feed on plant phloem sap that contains much sugar and some nonessential amino acids but is poor in lipids and proteins. conventionally, it has been believed that aphids substantially have no intestinal digestion of proteins. however, we here report an unexpected finding that cysteine protease genes of the family cathepsin b are massively amplified in the lineage of aphids and that many of the protease genes exhibit gut-specific overexpression. by making use of expressed sequen ... | 2008 | 17934209 |
| effect of seasonal abiotic conditions and field margin habitat on the activity of pandora neoaphidis inoculum on soil. | the ability of the aphid pathogenic fungus pandora neoaphidis to remain active in the absence of a resting stage through a combination of continuous infection and as conidia deposited on soil was assessed alongside the potential for planted field margins to act as a refuge for the fungus. p. neoaphidis was able to infect the pea aphid, acyrthosiphon pisum, when maintained under controlled conditions that simulated those that occur seasonally in the uk. although there was a significant inverse re ... | 2008 | 17964597 |
| analysis of heterochromatic epigenetic markers in the holocentric chromosomes of the aphid acyrthosiphon pisum. | monomethylated-k9 h3 histones (me9h3) and heterochromatin protein 1 (hp1) are reported as heterochromatin markers in several eukaryotes possessing monocentric chromosomes. in order to confirm that these epigenetic markers are evolutionarily conserved, we sequenced the hp1 cdna and verified the distribution of me9h3 histones and hp1 in the holocentric chromosomes of the aphid acyrthosiphon pisum. sequencing indicates that a. pisum hp1 cdna (called aphp1) is 1623 bp long, including a 170 bp long 5 ... | 2007 | 18004669 |
| population dynamics of defensive symbionts in aphids. | vertically transmitted micro-organisms can increase in frequency in host populations by providing net benefits to hosts. while laboratory studies have identified diverse beneficial effects conferred by inherited symbionts of insects, they have not explicitly examined the population dynamics of mutualist symbiont infection within populations. in the pea aphid, acyrthosiphon pisum, the inherited facultative symbiont, hamiltonella defensa, provides protection against parasitism by the wasp, aphidiu ... | 2008 | 18029301 |
| sex versus parthenogenesis: a transcriptomic approach of photoperiod response in the model aphid acyrthosiphon pisum (hemiptera: aphididae). | most aphids develop a cyclic parthenogenesis life-cycle. after several generations of viviparous parthenogenetic females, it follows a single annual generation of sexual individuals, usually in autumn, that mate and lay the sexual eggs. shortening of photoperiod at the end of the summer is a key factor inducing the sexual response. with the survey here reported we aimed at identifying a collection of candidate genes to participate at some point in the cascade of events that lead to the sexual ph ... | 2008 | 18065167 |
| the influence of natural enemies on wing induction in aphis fabae and megoura viciae (hemiptera: aphididae). | previous studies have shown that the aphid species, aphis fabae scopoli and megoura viciae buckton, do not produce winged offspring in the presence of natural enemies, in contrast to results for the pea aphid (acyrthosiphon pisum (harris)) and the cotton aphid (aphis gossypii glover); but these studies did not involve exposing aphids directly to natural enemies. we exposed colonies of both a. fabae and m. viciae to foraging lacewing (chrysoperla carnea (stephens)) larvae and found that the preda ... | 2008 | 18076776 |
| transmission of symbiotic bacteria buchnera to parthenogenetic embryos in the aphid acyrthosiphon pisum (hemiptera: aphidoidea). | all phloem-feeding aphids have an absolute requirement for their primary bacterial symbionts buchnera sp. the bacteria are transmitted vertically to either embryos in the viviparous morph or to eggs in the oviparous morph, with the implication that the symbiont population regularly passes through a genetic 'bottleneck', i.e. only a small proportion of the maternal symbiont population is transmitted to offspring. in this paper, we visualise this process in viviparous aphids using a specific immun ... | 2003 | 18089009 |
| real-time analysis of alarm pheromone emission by the pea aphid (acyrthosiphon pisum) under predation. | upon attack by predators or parasitoids, aphids emit volatile chemical alarm signals that warn other aphids of a potential risk of predation. release rate of the major constituent of the alarm pheromone in pea aphids (acyrthosiphon pisum), (e)-b-farnesene (ebf), was measured for all nymphal and the adult stage as aphids were attacked individually by lacewing (chrysoperla carnae) larvae. volatilization of ebf from aphids under attack was quantified continuously for 60 min at 2-min intervals with ... | 2008 | 18092189 |
| rarity of males in pea aphids results in mutational decay. | when females can reproduce without males, do males become an evolutionarily weaker sex whose genes experience mutational decay? we addressed this hypothesis in aphids, whose reproduction alternates between parthenogenetic and sexual forms: over the course of a year, there can be 10 to 20 generations of asexual females but only a single, if any, generation with males. we used microarray analyses to identify male-biased, asexual female-biased, and neutral genes. interspecific comparisons reveal ac ... | 2008 | 18174433 |
| evolutionary genetics of a defensive facultative symbiont of insects: exchange of toxin-encoding bacteriophage. | the facultative endosymbiont of aphids, hamiltonella defensa, kills parasitoid wasp larvae, allowing aphid hosts to survive and reproduce. this protection may depend on toxins that are encoded by the genomes of h. defensa and of its bacteriophage (apse). strains of h. defensa vary in degree of protection conferred upon acyrthosiphon pisum (pea aphid). although h. defensa is known to undergo some horizontal transmission among aphid maternal lineages, divergence, recombination, and population stru ... | 2008 | 18179430 |
| characterization of pea aphid resistance in medicago truncatula. | to achieve a thorough understanding of plant-aphid interactions, it is necessary to investigate in detail both the plant and insect side of the interaction. the pea aphid (pa; acyrthosiphon pisum) has been selected by an international consortium as the model species for genetics and genomics studies, and the model legume medicago truncatula is a host of this aphid. in this study, we identified resistance to pa in a m. truncatula line, 'jester', with well-characterized resistance to a closely rel ... | 2008 | 18184733 |
| identification of aphid salivary proteins: a proteomic investigation of myzus persicae. | the role of insect saliva in the first contact between an insect and a plant is crucial during feeding. some elicitors, particularly in insect regurgitants, have been identified as inducing plant defence reactions. here, we focused on the salivary proteome of the green peach aphid, myzus persicae. proteins were either directly in-solution digested or were separated by 2d sds-page before trypsin digestion. resulting peptides were then identified by mass spectrometry coupled with database investig ... | 2008 | 18353105 |
| insecticidal activity of a basement membrane-degrading protease against heliothis virescens (fabricius) and acyrthosiphon pisum (harris). | scathl is a cathepsin l-like cysteine protease derived from the flesh fly sarcophaga peregrina that functions in basement membrane (bm) remodeling during insect development. a recombinant baculovirus expressing scathl (acmlf9.scathl) kills larvae of the tobacco budworm, heliothis virescens, significantly faster than the wild-type virus. here, we show that the occurrence of larval melanization prior to death was closely associated with the onset of high cysteine protease activity of scathl in the ... | 2008 | 18395222 |
| intraguild interactions of aphidophagous predators in fields: effect of coccinella septempunctata and episyrphus balteatus occurrence on aphid infested plants. | intraguild relations between beneficial insects have become a major research topic in biological pest control. in order to understand the intraguild competitions between aphidophagous populations in natural conditions, a field experiment was carried out in the experimental farm of the gembloux agricultural university. as biological control of pests involve a community of diverse natural enemies, this experiment firstly aimed to assess the aphidophagous predator diversity and abundance in green p ... | 2007 | 18399466 |
| first results on the insecticidal action of saponins. | in the search for new, natural insecticides, numerous scientists are currently trying to obtain useful compound from plants. a possibly interesting class of molecules are the saponins, a group of steroidal or triterpenoidal secondary plant metabolites with divergent biological activities. in this study, we investigated the activity of saponins against living caterpillars spodoptera littoralis) and aphids (acyrthosiphon pisum) via treatment on artificial diets containing different concentrations ... | 2007 | 18399498 |
| whole-mount identification of gene transcripts in aphids: protocols and evaluation of probe accessibility. | in situ hybridization has become a powerful tool for detecting the temporal and spatial distribution of gene transcripts in prokaryotes and eukaryotes. we report an efficient protocol for whole-mount identification of the expression of mrnas in the parthenogenetic pea aphid acyrthosiphon pisum, an emerging model organism with a growing accumulation of genome sequencing data. in addition to steps common for most animal in situ hybridization protocols, we describe processing methods specific to ap ... | 2008 | 18481297 |
| [effects of cutting on the population dynamics of main insect pests on alfalfa]. | a systematic investigation was made on the effects of cutting on the population dynamics of main insect pests on alfalfa in dingxi of gansu province. the results showed that the effects of cutting varied significantly with the kinds of insect pests. the seasonal average population densities of therioaphis trifolii, acyrthosiphon pisum and thrips decreased significantly and maintained at a low level under the first cutting in early june, but less variation was observed under the second cutting in ... | 2008 | 18533546 |
| complex interactions between a plant pathogen and insect parasitoid via the shared vector-host: consequences for host plant infection. | plant viruses modify the development of their aphid vectors by inducing physiological changes in the shared host plant. the performance of hymenopterous parasitoids exploiting these aphids can also be modified by the presence of the plant pathogen. we used laboratory and glasshouse microcosms containing beans (vicia faba) as the host plant to examine the interactions between a plant virus (pea enation mosaic virus; pemv) and a hymenopterous parasitoid (aphidius ervi) that share the aphid vector/ ... | 2008 | 18566836 |
| a protein from the salivary glands of the pea aphid, acyrthosiphon pisum, is essential in feeding on a host plant. | in feeding, aphids inject saliva into plant tissues, gaining access to phloem sap and eliciting (and sometimes overcoming) plant responses. we are examining the involvement, in this aphid-plant interaction, of individual aphid proteins and enzymes, as identified in a salivary gland cdna library. here, we focus on a salivary protein we have arbitrarily designated protein c002. we have shown, by using rnai-based transcript knockdown, that this protein is important in the survival of the pea aphid ... | 2008 | 18621720 |
| featured organism: reductive evolution in bacteria: buchnera sp., rickettsia prowazekii and mycobacterium leprae. | obligate intracellular bacteria commonly have much reduced genome sizes compared to their nearest free-living relatives. one reason for this is reductive evolution: the loss of genes rendered non-essential due to the intracellular habitat. this can occur because of the presence of orthologous genes in the host, combined with the ability of the bacteria to import the protein or metabolite products of the host genes. in this article we take a look at three such bacteria whose genomes have been ful ... | 2001 | 18628941 |
| juvenile hormone titres and winged offspring production do not correlate in the pea aphid, acyrthosiphon pisum. | pea aphids, acyrthosiphon pisum, reproduce parthenogenetically and are wing-dimorphic such that offspring can develop into winged (alate) or unwinged (apterous) adults. alate induction is maternal and offspring phenotype is entirely determined by changes in the physiology and environment of the mother. juvenile hormones (jhs) have been implicated in playing a role in wing differentiation in aphids, however until recently, methods were not available to accurately quantify these insect hormones in ... | 2008 | 18634797 |
| population differentiation and genetic variation in performance on eight hosts in the pea aphid complex. | phytophagous insects frequently use multiple host-plant species leading to the evolution of specialized host-adapted populations and sometimes eventually to speciation. some insects are confronted with a large number of host-plant species, which may provide complex routes of gene flow between host-adapted populations. the pea aphid (acyrthosiphon pisum) attacks a broad range of plants in the fabaceae and it is known that populations on trifolium pratense and medicago sativa can be highly special ... | 2008 | 18647340 |
| emission of alarm pheromone in aphids: a non-contagious phenomenon. | in response to attack by natural enemies, most aphid species release an alarm pheromone that causes nearby conspecifics to cease feeding and disperse. the primary component of the alarm pheromone of most species studied is (e)-beta-farnesene. we recently demonstrated that the production and accumulation of (e)-beta-farnesene during development by juvenile aphids is stimulated by exposure to odor cues, most likely by (e)-beta-farnesene emitted by other colony members. here, we tested whether the ... | 2008 | 18704587 |
| do aphid colonies amplify their emission of alarm pheromone? | when aphids are attacked by natural enemies, they emit alarm pheromone to alert conspecifics. for most aphids tested, (e)-beta-farnesene (ebf) is the main, or only, constituent of the alarm pheromone. in response to alarm pheromone, alerted aphids drop off the plant, walk away, or attempt to elude predators. however, under natural conditions, ebf concentration might be low due to the low amounts emitted, to rapid air movement, or to oxidative degradation. to ensure that conspecifics are warned, ... | 2008 | 18704588 |
| the insecticidal activity of recombinant garlic lectins towards aphids. | the heterodimeric and homodimeric garlic lectins asai and asaii were produced as recombinant proteins in the yeast pichia pastoris. the proteins were purified as functional dimeric lectins, but underwent post-translational proteolysis. recombinant asaii was a single homogenous polypeptide which had undergone c-terminal processing similar to that occurring in planta. the recombinant asai was glycosylated and subject to variable and heterogenous proteolysis. both lectins showed insecticidal effect ... | 2008 | 18707000 |
| the genetic architecture of ecological specialization: correlated gene effects on host use and habitat choice in pea aphids. | genetic correlations among phenotypic characters result when two traits are influenced by the same genes or sets of genes. by reducing the degree to which traits in two environments can evolve independently (e.g., lande 1979; via and lande 1985), such correlations are likely to play a central role in both the evolution of ecological specialization and in its link to speciation. for example, negative genetic correlations between fitness traits in different environments (i.e., genetic trade-offs) ... | 2002 | 18707371 |
| in silico analyses of peptide paracrines/hormones in aphidoidea. | the aphidoidea is an insect superfamily comprising most of the known aphid species. while small in size, these animals are of considerable economic importance as many members of this taxon are serious agricultural pests, inflicting physical damage upon crop plants and serving as vectors in the transmission of viral plant diseases. in terms of identifying the paracrines/hormones used to modulate behavior, particularly peptides, members of the aphidoidea have largely been ignored, as it is not tra ... | 2008 | 18725225 |
| evaluation of artificial diets for rearing aphis glycines (hemiptera: aphididae). | artificial aphid diets have been previously developed for the pea aphid, acyrthosiphon pisum (harris), and the green peach aphid, myzus persicae (sulzer). the ability to rear aphids on an artificial diet allows for selectively adding or subtracting compounds from an aphid's food source to determine the effect on fecundity and longevity. five diets previously developed for the green peach aphid and the pea aphid were tested for their suitability for rearing soybean aphid, aphis glycines matsumura ... | 2008 | 18767731 |
| wounding-mediated gene expression and accelerated viviparous reproduction of the pea aphid acyrthosiphon pisum. | most insects mount a potent antimicrobial defence upon contact with microbes or microbe-associated pattern molecules. using a combined set of methods for analysis of insect innate immunity, we report here that piercing of the pea aphid acyrthosiphon pisum with a bacteria-contaminated needle elicits lysozyme-like activity in the haemolymph but no detectable activities against live bacteria. confirming these results, we found no homologues of known antimicrobial peptides in our cdna library genera ... | 2008 | 18823444 |
| plum pox in north america: identification of aphid vectors and a potential role for fruit in virus spread. | abstract thirteen aphid species were tested for their ability to transmit pennsylvania isolates of plum pox virus (ppv) collected in columbia (penn-3), franklin (penn-4), and york (penn-7) counties, pa. four species, aphis fabae, a. spiraecola, brachycaudus persicae, and myzus persicae, consistently transmitted ppv in preliminary transmission tests. two species, metopolophium dirhodum and rhopalosiphum padi, were occasional inefficient vectors. toxoptera citricida, from florida, also was an effe ... | 2004 | 18943108 |
| transmission efficiency of cucumber mosaic virus by aphids associated with virus epidemics in snap bean. | cucumber mosaic virus (cmv) is a major component of the virus complex that has become more pronounced in snap bean in the midwestern and northeastern united states since 2001. multiple-vector-transfer tests were done to estimate the cmv transmission efficiencies (p) of the main aphid species identified in commercial snap bean fields in new york and pennsylvania. the four most efficient vectors (p > 0.05) were aphis gossypii, a. glycines, acyrthosiphon pisum, and therioaphis trifolii, which were ... | 2008 | 18943413 |
| the n-terminal region of the readthrough domain is closely related to aphid vector specificity of soybean dwarf virus. | abstract it has been speculated that the n-terminal half of the readthrough domain (rtd) encoded by open reading frame 5 of soybean dwarf virus (sbdv) is related to the vector specificity. to further investigate this hypothesis, transmissibility via aphids was tested on 17 sbdv isolates and comparisons of the deduced amino acid sequences of the coat protein (cp) and other proteins encoded by the rtd were made between these isolates. isolates were distinguished into four strains: ys, causing yell ... | 2003 | 18943620 |
| identification, characterization, and relatedness of luteovirus isolates from forage legumes. | abstract virus isolates from forage legumes collected from eight different states were identified as luteoviruses closely related to soybean dwarf luteovirus dwarfing (sbdv-d) and yellowing (sbdv-y) described in japan. all isolates produced reddened leaf margins in subterranean clover and were transmitted in a persistent manner by acrythosiphon pisum, but not by aulacorthum solani. specific monoclonal antibodies raised against sbdv-y were differentially reactive with endemic isolates. immunoblot ... | 1999 | 18944749 |
| carbohydrate-binding activity of the type-2 ribosome-inactivating protein sna-i from elderberry (sambucus nigra) is a determining factor for its insecticidal activity. | in recent years, different classes of proteins have been reported to promote toxic effects when ingested. type-2 ribosome-inactivating proteins (rips) are a group of chimeric proteins built up of an a-chain with rna n-glycosidase activity and a b-chain with lectin activity. these proteins are thought to play a role in plant protection. sambucus nigra agglutinin i (sna-i) is a type-2 rip, isolated from the bark of elderberry (s. nigra l.). this study demonstrated the insecticidal potency of sna-i ... | 2008 | 18951590 |
| cis-nitromethylene neonicotinoids as new nicotinic family: synthesis, structural diversity, and insecticidal evaluation of hexahydroimidazo[1,2-alpha]pyridine. | a series of neonicotinoids analogues of hexahydroimidazo[1,2-alpha]pyridine were modified at 5-, 6-, and 7-positions, and their insecticidal activities were evaluated. introducing a methyl or ethyl at 7-position increased the insecticidal activities, while other substituents decreased activities. when alkyl substituents were introduced to 7-position, the insecticidal activities against pea aphids decreased in the order methyl (7a)>ethyl (7b)>n-butyl (7e)>phenyl (7f)>n-propyl (7c)>iso-propyl (7d) ... | 2008 | 18951786 |
| a water-specific aquaporin involved in aphid osmoregulation. | the osmotic pressure of plant phloem sap is generally higher than that of insect body fluids. water cycling from the distal to proximal regions of the gut is believed to contribute to the osmoregulation of aphids and other phloem-feeding insects, with the high flux of water mediated by a membrane-associated aquaporin. a putative aquaporin referred to as apaqp1 was identified by rt-pcr of rna isolated from the guts of pea aphids acyrthosiphon pisum. the apaqp1 protein has a predicted molecular ma ... | 2009 | 18983920 |
| baculovirus-expressed virus-like particles of pea enation mosaic virus vary in size and encapsidate baculovirus mrnas. | pea enation mosaic virus (pemv: family luteoviridae) is transmitted in a persistent, circulative manner by aphids. we inserted cdnas encoding the structural proteins of pemv, the coat protein (cp) and coat protein-read through domain (cprt) into the genome of the baculovirus autographa californica multiple nucleopolyhedrovirus with and without a histidine tag or an upstream kozak consensus sequence. the sf21 cell line provided the highest level of cp expression of the cell lines tested and resul ... | 2009 | 19013202 |
| the impact of floral resources and omnivory on a four trophic level food web. | omnivory is common among arthropods, but little is known about how availability of plant resources and prey affects interactions between species operating at the third and fourth trophic level. we used laboratory and field cage experiments to investigate how the provision of flowers affects an omnivorous lacewing, micromus tasmaniae (hemerobiidae) and its parasitoid anacharis zealandica (figitidae). the adult lacewing is a true omnivore that feeds on both floral resources and aphids, whereas the ... | 2009 | 19063752 |
| resource competition and shared natural enemies in experimental insect communities. | much theory has been developed to explore how competition for shared resources (exploitation competition) or the presence of shared natural enemies (apparent competition) might structure insect and other communities. it is harder to predict what happens when both processes operate simultaneously. we describe an experiment that attempted to explore how shared natural enemies and resource competition structured a simple experimental insect community. replicated communities were assembled in popula ... | 2009 | 19082628 |
| developmental expression of apnanos during oogenesis and embryogenesis in the parthenogenetic pea aphid acyrthosiphon pisum. | among genes that are preferentially expressed in germ cells, nanos and vasa are the two most conserved germline markers in animals. both genes are usually expressed in germ cells in the adult gonads, and often also during embryogenesis. both nanos-first or vasa-first expression patterns have been observed in embryos, implying that the molecular networks governing germline development vary among species. previously we identified apvasa, a vasa homologue expressed in germ cells throughout all deve ... | 2009 | 19123140 |
| symbiotic bacteria enable insect to use a nutritionally inadequate diet. | animals generally require a dietary supply of various nutrients (vitamins, essential amino acids, etc.) because their biosynthetic capabilities are limited. the capacity of aphids to use plant phloem sap, with low essential amino acid content, has been attributed to their symbiotic bacteria, buchnera aphidicola, which can synthesize these nutrients; but this has not been demonstrated empirically. we demonstrate here that phloem sap obtained from the severed stylets of pea aphids acyrthosiphon pi ... | 2009 | 19129128 |
| effect of wild flowers on oviposition of hippodamia variegata (coleoptera: coccinellidae) in the laboratory. | marginal vegetation in crops is very important for natural enemies and their pest control capacity. the effects of brassica nigra l. (brassicaceae), daucus carota l. (apiaceae), and sonchus oleraceous l. (asteraceae) flowers as supplemental food on the number of eggs laid during 7 d and on the preoviposition time in hippodamia variegata (goeze, 1777) were studied in the laboratory under conditions of several densities of acyrthosiphon pisum (harris, 1776). the results show the presence of flower ... | 2008 | 19133458 |
| host range expansion of an introduced insect pest through multiple colonizations of specialized clones. | asexuality confers demographic advantages to invasive taxa, but generally limits adaptive potential for colonizing of new habitats. therefore, pre-existing adaptations and habitat tolerance are essential in the success of asexual invaders. we investigated these key factors of invasiveness by assessing reproductive modes and host-plant adaptations in the pea aphid, acyrthosiphon pisum, a pest recently introduced into chile. the pea aphid encompasses lineages differing in their reproductive mode, ... | 2008 | 19140984 |
| the dynamics and time scale of ongoing genomic erosion in symbiotic bacteria. | among cellular organisms, symbiotic bacteria provide the extreme examples of genome degradation and reduction. however, only isolated snapshots of eroding symbiont genomes have previously been available. we documented the dynamics of symbiont genome evolution by sequencing seven strains of buchnera aphidicola from pea aphid hosts. we estimated a spontaneous mutation rate of at least 4 x 10(-9) substitutions per site per replication, which is more than 10 times as high as the rates previously est ... | 2009 | 19150844 |
| do plant viruses facilitate their aphid vectors by inducing symptoms that alter behavior and performance? | aphids can respond both positively and negatively to virus-induced modifications of the shared host plant. it can be speculated that viruses dependent on aphids for their transmission might evolve to induce changes in the host plant that attract aphids and improve their performance, subsequently enhancing the success of the pathogen itself. we studied how pea aphids [acyrthosiphon pisum (harris)] responded to infection of tic beans (vicia faba l.) by three viruses with varying degrees of depende ... | 2008 | 19161702 |
| pea aphid as both host and vector for the phytopathogenic bacterium pseudomonas syringae. | aphids are widespread agricultural pests that are capable of disseminating plant viral diseases; however, despite coming into frequent contact with epiphytic bacteria, aphids are considered to have no role in bacterial transmission. here, we demonstrate the ability of pea aphids to vector the phytopathogen pseudomonas syringae pv. syringae b728a (psyb728a). while feeding on plants colonized by epiphytic bacteria, aphids acquire the bacteria, which colonize the digestive tract, multiply, and are ... | 2009 | 19201955 |
| allelic and genotypic diversity in long-term asexual populations of the pea aphid, acyrthosiphon pisum in comparison with sexual populations. | many aphid species exhibit geographical variation in the mode of reproduction that ranges from cyclical parthenogenesis with a sexual phase to obligate parthenogenesis (asexual reproduction). theoretical studies predict that organisms reproducing asexually should maintain higher allelic diversity per locus but lower genotypic diversity than organisms reproducing sexually. to corroborate this hypothesis, we evaluated genotypic and allelic diversities in the sexual and asexual populations of the p ... | 2009 | 19207245 |
| the insect caspases. | developmental and tissue homeostasis is a delicate balance between cell proliferation and cell death. the activation of caspases, a conserved family of cysteine proteases, is a main event in the initiation and execution of programmed cell death. while caspases have been characterized from many organisms, comparatively little is known about insect caspases. in drosophila melanogaster, seven caspases have been characterized; three initiators and four effectors. in mosquitoes, several putative casp ... | 2009 | 19212814 |
| a positive trait-mediated indirect effect involving the natural enemies of competing herbivores. | trait-mediated indirect effects can have important effects on food web dynamics but are still poorly understood in the field. in a previous population cage study of a small community of aphids and an aphid natural enemy it was found that a trait-mediated indirect effect involving the natural enemy's behaviour was key to understanding community persistence. here evidence is presented that a related phenomenon involving some of the same species occurs in the field. surveys showed that two species ... | 2009 | 19214584 |
| genotypic variation and the role of defensive endosymbionts in an all-parthenogenetic host-parasitoid interaction. | models of host-parasite coevolution predict pronounced genetic dynamics if resistance and infectivity are genotype-specific or associated with costs, and if selection is fueled by sufficient genetic variation. we addressed these assumptions in the black bean aphid, aphis fabae, and its parasitoid lysiphlebus fabarum. parasitoid genotypes differed in infectivity and host clones exhibited huge variation for susceptibility. this variation occurred at two levels. clones harboring hamiltonella defens ... | 2009 | 19228189 |
| a fragile metabolic network adapted for cooperation in the symbiotic bacterium buchnera aphidicola. | in silico analyses provide valuable insight into the biology of obligately intracellular pathogens and symbionts with small genomes. there is a particular opportunity to apply systems-level tools developed for the model bacterium escherichia coli to study the evolution and function of symbiotic bacteria which are metabolically specialised to overproduce specific nutrients for their host and, remarkably, have a gene complement that is a subset of the e. coli genome. | 2009 | 19232131 |
| the readthrough domain of pea enation mosaic virus coat protein is not essential for virus stability in the hemolymph of the pea aphid. | a fraction of the coat protein (cp) subunits in virions of members of the family luteoviridae contain a c-terminal extension called the readthrough domain (rtd). the rtd is necessary for persistent aphid transmission, but its role is unknown. it has been reported to be required for virion stability in the hemolymph. here, we tested whether this was the case for pea enation mosaic virus (pemv) virions in the pea aphid (acyrthosiphon pisum) using rna1delta, a natural deletion mutant lacking the mi ... | 2009 | 19240978 |
| species response to environmental change: impacts of food web interactions and evolution. | how environmental change affects species abundances depends on both the food web within which species interact and their potential to evolve. using field experiments, we investigated both ecological and evolutionary responses of pea aphids (acyrthosiphon pisum), a common agricultural pest, to increased frequency of episodic heat shocks. one predator species ameliorated the decrease in aphid population growth with increasing heat shocks, whereas a second predator did not, with this contrast cause ... | 2009 | 19265021 |
| aphids acquired symbiotic genes via lateral gene transfer. | aphids possess bacteriocytes, which are cells specifically differentiated to harbour the obligate mutualist buchnera aphidicola (gamma-proteobacteria). buchnera has lost many of the genes that appear to be essential for bacterial life. from the bacteriocyte of the pea aphid acyrthosiphon pisum, we previously identified two clusters of expressed sequence tags that display similarity only to bacterial genes. southern blot analysis demonstrated that they are encoded in the aphid genome. in this stu ... | 2009 | 19284544 |
| host races of the pea aphid acyrthosiphon pisum differ in male wing phenotypes. | the evolution of reproductive isolation without geographic isolation (sympatric speciation) has recently gained strong theoretical and empirical supports. it is now widely admitted that many host-specific phytophagous insect species have arisen through shifting and adapting to new plants. the pea aphid acyrthosiphon pisum has received considerable attention in this context and is now considered as a probable case of incipient sympatric speciation through host specialization. in europe, three hos ... | 2010 | 19323853 |
| discrimination of alarm pheromone (e)-beta-farnesene by aphid odorant-binding proteins. | obps have been recently demonstrated to be required for odour perception in insects and directly involved in odour discrimination. in aphids they might represent new interesting targets for the control of their population in agriculture. based on sequence information available in the est database, we have cloned four genes encoding odorant-binding proteins (obp) in acyrthosiphon pisum and homologous genes in other aphid species. unlike obps from other orders of insects, that are greatly divergen ... | 2009 | 19328854 |
| hitching a lift on the road to speciation. | understanding how speciation can take place in the presence of homogenizing gene flow remains a major challenge in evolutionary biology. in the early stages of ecological speciation, reproductive isolation between populations occupying different habitats is expected to be concentrated around genes for local adaptation. these genomic regions will show high divergence while gene exchange in other regions of the genome should continue relatively unimpaired, resulting in low levels of differentiatio ... | 2008 | 19378398 |
| a continuum of genetic divergence from sympatric host races to species in the pea aphid complex. | sympatric populations of insects adapted to different host plants, i.e., host races, are good models to investigate how natural selection can promote speciation in the face of ongoing gene flow. however, host races are documented in very few model systems and their gradual evolution into good species, as assumed under a darwinian view of species formation, lacks strong empirical support. we aim at resolving this uncertainty by investigating host specialization and gene flow among populations of ... | 2009 | 19380742 |
| the secreted salivary proteome of the pea aphid acyrthosiphon pisum characterised by mass spectrometry. | nine proteins secreted in the saliva of the pea aphid acyrthosiphon pisum were identified by a proteomics approach using ge-lc-ms/ms and lc-ms/ms, with reference to est and genomic sequence data for a. pisum. four proteins were identified by their sequences: a homolog of angiotensin-converting enzyme (an m2 metalloprotease), an m1 zinc-dependant metalloprotease, a glucose-methanol-choline (gmc)-oxidoreductase and a homolog to regucalcin (also known as senescence marker protein 30). the other fiv ... | 2009 | 19402045 |
| lateral gene transfer between prokaryotes and multicellular eukaryotes: ongoing and significant? | the expansion of genome sequencing projects has produced accumulating evidence for lateral transfer of genes between prokaryotic and eukaryotic genomes. however, it remains controversial whether these genes are of functional importance in their recipient host. nikoh and nakabachi, in a recent paper in bmc biology, take a first step and show that two genes of bacterial origin are highly expressed in the pea aphid acyrthosiphon pisum. active gene expression of transferred genes is supported by thr ... | 2009 | 19416510 |
| effects of bacillus thuringiensis delta-endotoxins on the pea aphid (acyrthosiphon pisum). | four bacillus thuringiensis delta-endotoxins, cry3a, cry4aa, cry11aa, and cyt1aa, were found to exhibit low to moderate toxicity on the pea aphid, acyrthosiphon pisum, in terms both of mortality and growth rate. cry1ab was essentially nontoxic except at high rates. to demonstrate these effects, we had to use exhaustive buffer-based controls. | 2009 | 19447954 |
| similar patterns of linkage disequilibrium and nucleotide diversity in native and introduced populations of the pea aphid, acyrthosiphon pisum. | the pea aphid, acyrthosiphon pisum, is an emerging genomic model system for studies of polyphenisms, bacterial symbioses, host-plant specialization, and the vectoring of plant viruses. here we provide estimates of nucleotide diversity and linkage disequilibrium (ld) in native (european) and introduced (united states) populations of the pea aphid. because introductions can cause population bottlenecks, we hypothesized that u.s. populations harbor lower levels of nucleotide diversity and higher le ... | 2009 | 19470181 |
| acid-base-driven matrix-assisted mass spectrometry for targeted metabolomics. | the ability to charge huge biomolecules without breaking them apart has made matrix-assisted laser desorption/ionization (maldi) mass spectrometry an indispensable tool for biomolecular analysis. conventional, empirically selected matrices produce abundant matrix ion clusters in the low-mass region (<500 da), hampering the application of maldi-ms to metabolomics. an ionization mode of maild, a rational protocol for matrix selection based on brønsted-lowry acid-base theory and its application to ... | 2009 | 19520825 |
| large gene family expansions and adaptive evolution for odorant and gustatory receptors in the pea aphid, acyrthosiphon pisum. | gaining insight into the mechanisms of chemoreception in aphids is of primary importance for both integrative studies on the evolution of host plant specialization and applied research in pest control management because aphids rely on their sense of smell and taste to locate and assess their host plants. we made use of the recent genome sequence of the pea aphid, acyrthosiphon pisum, to address the molecular characterization and evolution of key molecular components of chemoreception: the odoran ... | 2009 | 19542205 |
| impact of environmental stress on aphid clonal resistance to parasitoids: role of hamiltonella defensa bacterial symbiosis in association with a new facultative symbiont of the pea aphid. | resistance to endoparasitoids in aphids involves complex interactions between insect and microbial players. it is now generally accepted that the facultative bacterial symbiont hamiltonella defensa of the pea aphid acyrthosiphon pisum is implicated in its resistance to the parasitoid aphidius ervi. it has also been shown that heat negatively affects pea aphid resistance, suggesting the thermosensitivity of its defensive symbiosis. here we examined the effects of heat and uv-b on the resistance o ... | 2009 | 19545573 |
| effects of manduca sexta allatostatin and an analog on the pea aphid acyrthosiphon pisum (hemiptera: aphididae) and degradation by enzymes from the aphid gut. | the c-type allatostatin, manduca sexta allatostatin (manse-as) and the analog delta r(3)delta r(5)manse-as, where r residues were replaced by their d-isomers, were tested for oral toxicity against the pea aphid acyrthosiphon pisum (harris) by incorporation into an artificial diet. both peptides had significant dose-dependent feeding suppression effects, resulting in mortality, reduced growth and fecundity compared with control insects. the delta r(3)delta r(5)manse-as analog had an estimated lc( ... | 2010 | 19560498 |
| morph-dependent expression and subcellular localization of host serine carboxypeptidase in bacteriocytes of the pea aphid associated with degradation of the endosymbiotic bacterium buchnera. | pea aphids form a mutualistic association with the endosymbiotic bacterium buchnera, which is harbored in specialized host cells called bacteriocytes. the adult aphids display dimorphism in which there are winged and wingless morphs. we previously reported that the buchnera density in bacteriocytes of the winged morph (alate) decreases around final ecdysis, whereas that in the wingless morph (aptera) does not decrease; the decrease in density in alatae is accompanied by activation of the host ly ... | 2009 | 19583501 |
| antifeedant activity and high mortality in the pea aphid acyrthosiphon pisum (hemiptera: aphidae) induced by biostable insect kinin analogs. | the insect kinins are multifunctional neuropeptides found in a variety of arthropod species, including the pea aphid acyrthosiphon pisum (hemiptera: aphidae). a series of biostable insect kinin analogs based on the shared c-terminal pentapeptide core region were fed in solutions of artificial diet to the pea aphid over a period of 3 days and evaluated for antifeedant and aphicidal activity. the analogs contained either alpha,alpha-disubstituted or beta-amino acids in key positions to enhance res ... | 2010 | 19596392 |
| evolution of the gene lineage encoding the carbon dioxide receptor in insects. | a heterodimer of the insect chemoreceptors gr21a and gr63a has been shown to be the carbon dioxide receptor in drosophila melanogaster (meigen) (diptera: drosophilidae). comparison of the genes encoding these two proteins across the 12 available drosophilid fly genomes allows refined definition of their n-termini. these genes are highly conserved, along with a paralog of gr21a, in the anopheles gambiae, aedes aegypti, and culex pipiens mosquitoes, as well as in the silk moth bombyx mori and the ... | 2009 | 19613462 |
| profiling the repertoire of phenotypes influenced by environmental cues that occur during asexual reproduction. | the aphid acyrthosiphon pisum population is composed of different morphs, such as winged and wingless parthenogens, males, and sexual females. the combined effect of reduced photoperiodicity and cold in fall triggers the apparition of sexual morphs. in contrast they reproduce asexually in spring and summer. in our current study, we provide evidence that clonal individuals display phenotypic variability within asexual morph categories. we describe that clones sharing the same morphological featur ... | 2009 | 19635846 |
| reconstitution of authentic nanovirus from multiple cloned dnas. | we describe a new plant single-stranded dna (ssdna) virus, a nanovirus isolate originating from the faba bean in ethiopia. we applied rolling circle amplification (rca) to extensively copy the individual circular dnas of the nanovirus genome. by sequence analyses of more than 208 individually cloned genome components, we obtained a representative sample of eight polymorphic swarms of circular dnas, each about 1 kb in size. from these heterogeneous dna populations after rca, we inferred consensus ... | 2009 | 19656882 |