| rnai knockdown of a salivary transcript leading to lethality in the pea aphid, acyrthosiphon pisum. | abstract injection of sirna (small interfering rna) into parthenogenetic adult pea aphids (acyrthosiphon pisum) is shown here to lead to depletion of a target salivary gland transcript. the sirna was generated from double stranded rna that covered most of the open reading frame of the transcript, which we have called coo2. the coo2 transcript level decreases dramatically over a 3-day period after injection of sirna. with a lag of 1 to 2 days, the sicoo2-rna injected insects died, on average 8 da ... | 0 | 20233093 |
| deep rna-seq profile reveals biodiversity, plant-microbe interactions and a large family of nbs-lrr resistance genes in walnut (juglans regia) tissues. | deep rna-seq profiling, a revolutionary method used for quantifying transcriptional levels, often includes non-specific transcripts from other co-existing organisms in spite of stringent protocols. using the recently published walnut genome sequence as a filter, we present a broad analysis of the rna-seq derived transcriptome profiles obtained from twenty different tissues to extract the biodiversity and possible plant-microbe interactions in the walnut ecosystem in california. since the residua ... | 2016 | 26883051 |
| insulin-related peptide 5 is involved in regulating embryo development and biochemical composition in pea aphid with wing polyphenism. | in aphids there is a fecundity-dispersal trade-off between wingless and winged morphs. recent research on the molecular mechanism of wing morphs associated with dispersal reveals that insulin receptors in the insulin signaling (is) pathway regulate alternation of wing morphs in planthoppers. however, little is known about whether genes in the is pathway are involved in developmental regulation in aphid nymphs with different wing morphs. in this study, we show that expression of the insulin-relat ... | 2016 | 26903881 |
| molecular characterization of the aphis gossypii olfactory receptor gene families. | the cotton aphid, aphis gossypii glover, is a polyphagous pest that inflicts great damage to cotton yields worldwide. antennal olfaction, which is extremely important for insect survival, mediates key behaviors such as host preference, mate choice, and oviposition site selection. in insects, odor detection is mediated by odorant receptors (ors) and ionotropic receptors (irs), which ensure the specificity of the olfactory sensory neuron responses. in this study, our aim is to identify chemosensor ... | 2014 | 24971460 |
| retargeting of the bacillus thuringiensis toxin cyt2aa against hemipteran insect pests. | although transgenic crops expressing bacillus thuringiensis (bt) toxins have been used successfully for management of lepidopteran and coleopteran pest species, the sap-sucking insects (hemiptera) are not particularly susceptible to bt toxins. to overcome this limitation, we demonstrate that addition of a short peptide sequence selected for binding to the gut of the targeted pest species serves to increase toxicity against said pest. insertion of a 12-aa pea aphid gut-binding peptide by adding t ... | 2013 | 23650347 |
| the evolution of the histone methyltransferase gene su(var)3-9 in metazoans includes a fusion with and a re-fission from a functionally unrelated gene. | in eukaryotes, histone h3 lysine 9 (h3k9) methylation is a common mechanism involved in gene silencing and the establishment of heterochromatin. the loci of the major heterochromatic h3k9 methyltransferase su(var)3-9 and the functionally unrelated gamma subunit of the translation initiation factor eif2 are fused in drosophila melanogaster. here we examined the phylogenetic distribution of this unusual gene fusion and the molecular evolution of the h3k9 hmtase su(var)3-9. | 2006 | 16512904 |
| expansion of genes encoding pirna-associated argonaute proteins in the pea aphid: diversification of expression profiles in different plastic morphs. | piwi-interacting rnas (pirnas) are known to regulate transposon activity in germ cells of several animal models that propagate sexually. however, the role of pirnas during asexual reproduction remains almost unknown. aphids that can alternate sexual and asexual reproduction cycles in response to seasonal changes of photoperiod provide a unique opportunity to study pirnas and the pirna pathway in both reproductive modes. taking advantage of the recently sequenced genome of the pea aphid acyrthosi ... | 2011 | 22162754 |
| 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 |
| evolutionary study of duplications of the mirna machinery in aphids associated with striking rate acceleration and changes in expression profiles. | the sequencing of the genome of the pea aphid acyrthosiphon pisum revealed an unusual expansion of the mirna machinery, with two argonaute-1, two dicer-1 and four pasha gene copies. in this report, we have undertaken a deeper evolutionary analysis of the phylogenetic timing of these gene duplications and of the associated selective pressures by sequencing the two copies of ago-1 and dcr-1 in different aphid species of the subfamily aphidinae. we have also carried out an analysis of the expressio ... | 2012 | 23145470 |
| parallel duplication and partial subfunctionalization of β-catenin/armadillo during insect evolution. | β-catenin is a multifunctional scaffolding protein with roles in wnt signaling, cell adhesion, and centrosome separation. here, we report on independent duplications of the insect β-catenin ortholog armadillo (arm) in the red flour beetle tribolium castaneum and the pea aphid acyrthosiphon pisum. detailed sequence analysis shows that in both species, one paralog lost critical residues of the α-catenin binding domain, which is essential for cell adhesion, and accumulated a dramatically higher num ... | 2011 | 21890476 |
| house fly (musca domestica l.) attraction to insect honeydew. | house flies are of major concern as vectors of food-borne pathogens to food crops. house flies are common pests on cattle feedlots and dairies, where they develop in and feed on animal waste. by contacting animal waste, house flies can acquire human pathogenic bacteria such as escherichia coli and salmonella spp., in addition to other bacteria, viruses, or parasites that may infect humans and animals. the subsequent dispersal of house flies from animal facilities to nearby agricultural fields co ... | 2015 | 25970333 |
| deep sequencing of organ- and stage-specific micrornas in the evolutionarily basal insect blattella germanica (l.) (dictyoptera, blattellidae). | micrornas (mirnas) have been reported as key regulators at post-transcriptional level in eukaryotic cells. in insects, most of the studies have focused in holometabolans while only recently two hemimetabolans (locusta migratoria and acyrthosiphon pisum) have had their mirnas identified. therefore, the study of the mirnas of the evolutionarily basal hemimetabolan blattella germanica may provide valuable insights on the structural and functional evolution of mirnas. | 2011 | 21552535 |
| genome-wide annotation and functional identification of aphid glut-like sugar transporters. | phloem feeding insects, such as aphids, feed almost continuously on plant phloem sap, a liquid diet that contains high concentrations of sucrose (a disaccharide comprising of glucose and fructose). to access the available carbon, aphids hydrolyze sucrose in the gut lumen and transport its constituent monosaccharides, glucose and fructose. although sugar transport plays a critical role in aphid nutrition, the molecular basis of sugar transport in aphids, and more generally across all insects, rem ... | 2014 | 25091229 |
| aphids: a model for polyphenism and epigenetics. | environmental conditions can alter the form, function, and behavior of organisms over short and long timescales, and even over generations. aphid females respond to specific environmental cues by transmitting signals that have the effect of altering the development of their offspring. these epigenetic phenomena have positioned aphids as a model for the study of phenotypic plasticity. the molecular basis for this epigenetic inheritance in aphids and how this type of inheritance system could have ... | 2012 | 22567389 |
| bioinformatic prediction, deep sequencing of micrornas and expression analysis during phenotypic plasticity in the pea aphid, acyrthosiphon pisum. | post-transcriptional regulation in eukaryotes can be operated through microrna (mirnas) mediated gene silencing. mirnas are small (18-25 nucleotides) non-coding rnas that play crucial role in regulation of gene expression in eukaryotes. in insects, mirnas have been shown to be involved in multiple mechanisms such as embryonic development, tissue differentiation, metamorphosis or circadian rhythm. insect mirnas have been identified in different species belonging to five orders: coleoptera, dipter ... | 2010 | 20444247 |
| transcriptome analysis of sexually dimorphic chinese white wax scale insects reveals key differences in developmental programs and transcription factor expression. | the chinese white wax scale insect, ericerus pela, represents one of the most dramatic examples of sexual dimorphism in any insect species. in this study, we showed that although e. pela males display complete metamorphosis similar to holometabolous insects, the species forms the sister group to acyrthosiphon pisum and cluster with hemimetabolous insects. the gene expression profile and gene ontology (go) analyses revealed that the two sexes engaged in distinct developmental programs. in particu ... | 2015 | 25634031 |
| molecular cloning, expression pattern and polymorphisms of nadph-cytochrome p450 reductase in the bird cherry-oat aphid rhopalosiphum padi (l.). | nadph-cytochrome p450 reductase (cpr) plays an important role in the cytochrome p450 (cyp)-mediated metabolism of endogenous and exogenous substrates. cpr has been found to be associated with insecticide metabolism and resistance in many insects. however, information regarding cpr in the bird cherry-oat aphid, rhopalosiphum padi, is unavailable. in the current study, a full-length cdna (2,476 bp) of cpr (rpcpr) encoding 681 amino acids was cloned from r. padi. nucleotide sequence and deduced ami ... | 2016 | 27124302 |
| feeding-based rna interference of a gap gene is lethal to the pea aphid, acyrthosiphon pisum. | the gap gene hunchback (hb) is a key regulator in the anteroposterior patterning of insects. loss-of-function of hb resulted in segmentation defects in the next generation. in this paper, hb expression level was investigated at different developmental stages of the pea aphid, acyrthosiphon pisum (ap). aphb mrna was most early detected at the first instar stage and showed an incontinuous increase in the whole life cycle. ingested rna interference was performed at the second instar stage to knockd ... | 2012 | 23144942 |
| modification of cry4aa toward improved toxin processing in the gut of the pea aphid, acyrthosiphon pisum. | aphids are sap-sucking insects (order: hemiptera) that cause extensive damage to a wide range of agricultural crops. our goal was to optimize a naturally occurring insecticidal crystalline (cry) toxins produced by the soil-dwelling bacterium bacillus thuringiensis for use against the pea aphid, acyrthosiphon pisum. on the basis that activation of the cry4aa toxin is a rate-limiting factor contributing to the relatively low aphicidal activity of this toxin, we introduced cathepsin l and cathepsin ... | 2016 | 27171411 |
| aphid polyphenisms: trans-generational developmental regulation through viviparity. | polyphenism, in which multiple discrete phenotypes develop from a single genotype, is considered to have contributed to the evolutionary success of aphids. of the various polyphenisms observed in the complex life cycle of aphids, the reproductive and wing polyphenisms seen in most aphid species are conspicuous. in reproductive polyphenism, the reproductive modes can change between viviparous parthenogenesis and sexual reproduction in response to the photoperiod. under short-day conditions in aut ... | 2014 | 24478714 |
| transcriptomic and proteomic analyses of seasonal photoperiodism in the pea aphid. | aphid adaptation to harsh winter conditions is illustrated by an alternation of their reproductive mode. aphids detect photoperiod shortening by sensing the length of the night and switch from viviparous parthenogenesis in spring and summer, to oviparous sexual reproduction in autumn. the photoperiodic signal is transduced from the head to the reproductive tract to change the fate of the future oocytes from mitotic diploid embryogenesis to haploid formation of gametes. this process takes place i ... | 2009 | 19788735 |
| the differential effect of low-dose mixtures of four pesticides on the pea aphid acyrthosiphon pisum. | the modes of action of most insecticides are known, but little information exists regarding the toxicological interactions involving insecticide mixtures at low doses. the effects of mixtures of four insecticides were investigated using lc10 values (concentration leading to 10% mortality), acetamiprid (ace, 0.235 µg/ml), chlorpyriphos (chl, 107.0 µg/ml), deltamethrin (del, 5.831 µg/ml), and fipronil (fip, 3.775 µg/ml) on the larvae of the pea aphid, acyrthosiphon pisum. after 24 h exposure, 6 of ... | 2016 | 27754329 |
| isolation and identification of culturable bacteria from honeydew of whitefly, bemisia tabaci (g.) (hemiptera: aleyrodidae). | bemisia tabaci (g.) is an important pest and a vector of gemini viruses infecting plants. during the process of feeding b. tabaci excretes honeydew which is rich in nutrients, and an excellent medium for microbial growth. recent report proved that volatile emitted by the honeydew associated bacteria of aphid, acyrthosiphon pisum harris was involved in natural enemy calling. thus understanding the honeydew associated bacteria is of paramount importance from the non-chemical method of insect pest ... | 2014 | 25606395 |
| new cyt-like δ-endotoxins from dickeya dadantii: structure and aphicidal activity. | in the track of new biopesticides, four genes namely cyta, cytb, cytc and cytd encoding proteins homologous to bacillus thuringiensis (bt) cyt toxins have been identified in the plant pathogenic bacteria dickeya dadantii genome. here we show that three cyt-like δ-endotoxins from d. dadantii (cyta, cytb and cytc) are toxic to the pathogen of the pea aphid acyrthosiphon pisum in terms of both mortality and growth rate. the phylogenetic analysis of the comprehensive set of cyt toxins available in g ... | 2015 | 25740111 |
| aphicidal efficacy of scorpion- and spider-derived neurotoxins. | insect-specific neurotoxins that act within the insect hemocoel (body cavity) represent an untapped resource for insect pest management. on the basis of recent advances made in development of appropriate delivery systems for transport of these toxins from the insect gut, across the gut epithelium to their target site, we screened neurotoxins derived from scorpion or spider venom for efficacy against the pea aphid, acyrthosiphon pisum, and the green peach aphid, myzus persicae. toxins were select ... | 2013 | 23651761 |
| the effects of bean leafroll virus on life history traits and host selection behavior of specialized pea aphid (acyrthosiphon pisum, hemiptera: aphididae) genotypes. | intraspecific specialization by insect herbivores on different host plant species contributes to the formation of genetically distinct "host races," but the effects of plant virus infection on interactions between specialized herbivores and their host plants have barely been investigated. using three genetically and phenotypically divergent pea aphid clones (acyrthosiphon pisum l.) adapted to either pea (pisum sativum l.) or alfalfa (medicago sativa l.), we tested how infection of these hosts by ... | 2017 | 28062535 |
| symbiont-mediated protection against fungal pathogens in pea aphids: a role for pathogen specificity? | here we show that a bacterial endosymbiont, regiella insecticola, protects pea aphids (acyrthosiphon pisum) from the aphid-specific fungal entomopathogen zoophthora occidentalis but not from the generalist insect fungal pathogen beauveria bassiana. this finding highlights the complex influence of fungi on the dynamics of this economically important agricultural pest. | 2013 | 23354709 |
| intraspecific genetic variation in hosts affects regulation of obligate heritable symbionts. | symbiotic relationships promote biological diversification by unlocking new ecological niches. over evolutionary time, hosts and symbionts often enter intimate and permanent relationships, which must be maintained and regulated for both lineages to persist. many insect species harbor obligate, heritable symbiotic bacteria that provision essential nutrients and enable hosts to exploit niches that would otherwise be unavailable. hosts must regulate symbiont population sizes, but optimal regulation ... | 2016 | 27799532 |
| stable isotope studies reveal pathways for the incorporation of non-essential amino acids in acyrthosiphon pisum (pea aphids). | plant roots incorporate inorganic nitrogen into the amino acids glutamine, glutamic acid, asparagine and aspartic acid, which together serve as the primary metabolites of nitrogen transport to other tissues. given the preponderance of these four amino acids, phloem sap is a nutritionally unbalanced diet for phloem-feeding insects. therefore, aphids and other phloem feeders typically rely on microbial symbionts for the synthesis of essential amino acids. to investigate the metabolism of the four ... | 2015 | 26632455 |
| do bacterial symbionts govern aphid's dropping behavior? | defensive symbiosis is amongst nature's most important interactions shaping the ecology and evolution of all partners involved. the pea aphid, acyrthosiphon pisum harris (hemiptera: aphididae), harbors one obligatory bacterial symbiont and up to seven different facultative symbionts, some of which are known to protect the aphid from pathogens, natural enemies, and other mortality factors. pea aphids typically drop off the plant when a mammalian herbivore approaches it to avoid incidental predati ... | 2015 | 26313964 |
| proton-dependent glutamine uptake by aphid bacteriocyte amino acid transporter apglnt1. | aphids house large populations of the gammaproteobacterial symbiont buchnera aphidicola in specialized bacteriocyte cells. the combined biosynthetic capability of the holobiont (acyrthosiphon pisum and buchnera) is sufficient for biosynthesis of all twenty protein coding amino acids, including amino acids that animals alone cannot synthesize; and that are present at low concentrations in a. pisum's plant phloem sap diet. collaborative holobiont amino acid biosynthesis depends on glutamine import ... | 2015 | 26028424 |
| detection and decay rates of prey and prey symbionts in the gut of a predator through metagenomics. | dna methods are useful to identify ingested prey items from the gut of predators, but reliable detection is hampered by low amounts of degraded dna. pcr-based methods can retrieve minute amounts of starting material but suffer from amplification biases and cross-reactions with the predator and related species genomes. here, we use pcr-free direct shotgun sequencing of total dna isolated from the gut of the harlequin ladybird harmonia axyridis at five time points after feeding on a single pea aph ... | 2015 | 25545417 |
| comparative transmission of two cucumber mosaic virus isolates by two color morphs of acyrthosiphon pisum (harris). | cucumber mosaic virus (cmv) is one of the most important legume-infecting viruses, which is transmitted effectively by pea aphid acyrthosiphon pisum (harris) (hem: aphididae). transmission efficiency of two cmv isolates (as and kh from cowpea and bean hosts, resp.) by red and green color morphs of pea aphid were evaluated on bean plants. triple-antibody sandwich elisa (tas-elisa) using cmv-specific monoclonal antibodies revealed that both cmv isolates belonged to the serotype ii. bean plants ino ... | 2012 | 22720705 |
| stem nematode counteracts plant resistance of aphids in alfalfa, medicago sativa. | plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. as plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. this study examined the effect of nematode-resistant var ... | 2014 | 25261892 |
| natural occurrence of entomophthoroid fungi of aphid pests on medicago sativa l. in argentina. | four species of entomophthoroid fungi, pandora neoaphidis (entomophthorales: entomophthoraceae), zoophthora radicans (entomophthorales: entomophthoraceae), entomophthora planchoniana (entomophthorales: entomophthoraceae) and neozygites fresenii (neozygitales: neozygitaceae) were found to infect aphis craccivora, therioaphis trifolii, and acyrthosiphon pisum and unidentified species of acyrthosiphon on lucerne in argentina. samples were collected from five sites (ceres, rafaela, sarmiento, monte ... | 2014 | 24721275 |
| peroxiredoxin 1 protects the pea aphid acyrthosiphon pisum from oxidative stress induced by micrococcus luteus infection. | reactive oxygen species (ross) are generated in organisms in response to infections caused by invading microbes. however, excessive ross will inflict oxidative damage on the host. peroxiredoxins (prxs) are antioxidative enzymes that may eliminate ross efficiently. in this study, apprx1 from the pea aphid acyrthosiphon pisum was cloned, and its function was investigated in vitro and in vivo. in the presence of dtt, recombinant apprx1 protein from escherichia coli showed antioxidative activity by ... | 2015 | 25817695 |
| exposure to bacterial signals does not alter pea aphids' survival upon a second challenge or investment in production of winged offspring. | pea aphids have an obligate nutritional symbiosis with the bacteria buchneraaphidicola and frequently also harbor one or more facultative symbionts. aphids are also susceptible to bacterial pathogen infections, and it has been suggested that aphids have a limited immune response towards such pathogen infections compared to other, more well-studied insects. however, aphids do possess at least some of the genes known to be involved in bacterial immune responses in other insects, and immune-compete ... | 2013 | 24009760 |
| influence of diet on fecundity, immune defense and content of 2-isopropyl-3-methoxypyrazine in harmonia axyridis pallas. | food type can affect all functional aspects of an insect's life. we investigated the effects of different diet regimes on life history parameters of the ladybird beetle harmonia axyridis. furthermore, we tested the importance of elytral color, sex, and diet on chemical and immune defense in this species. we also compared hemolymph from cohorts of h. axyridis and coccinella septempunctata (coleoptera: coccinellidae) fed different diets to examine effects on the 2-isopropyl-3-methoxypyrazine (ipmp ... | 2012 | 22648506 |
| characterization of a gene encoding prohibitin in silkworm, bombyx mori. | prohibitin (phb) is an evolutionarily conserved multifunctional protein with ubiquitous expression. however, its molecular roles are largely unknown. | 2012 | 22450364 |
| evidence of horizontal transfer of non-autonomous lep1 helitrons facilitated by host-parasite interactions. | horizontal transfer (ht) of transposable elements has been recognized to be a major force driving genomic variation and biological innovation of eukaryotic organisms. however, the mechanisms of ht in eukaryotes remain poorly appreciated. the non-autonomous helitron family, lep1, has been found to be widespread in lepidopteran species, and showed little interspecific sequence similarity of acquired sequences at 3' end, which makes lep1 a good candidate for the study of ht. in this study, we descr ... | 2014 | 24874102 |
| horizontal transfer of facultative endosymbionts is limited by host relatedness. | heritable microbial symbionts can have important effects on many aspects of their hosts' biology. acquisition of a novel symbiont strain can provide fitness benefits to the host, with significant ecological and evolutionary consequences. we measured barriers to horizontal transmission by artificially transferring facultative symbionts from the grain aphid, sitobion avenae, and five other aphid species into two clonal genotypes of s. avenae. we found the symbiont hamiltonella defensa establishes ... | 2015 | 26332792 |
| patterns, causes and consequences of defensive microbiome dynamics across multiple scales. | the microbiome can significantly impact host phenotypes and serve as an additional source of heritable genetic variation. while patterns across eukaryotes are consistent with a role for symbiotic microbes in host macroevolution, few studies have examined symbiont-driven host evolution or the ecological implications of a dynamic microbiome across temporal, spatial or ecological scales. the pea aphid, acyrthosiphon pisum, and its eight heritable bacterial endosymbionts have served as a model for s ... | 2015 | 25683348 |
| genetic variation in resistance and fecundity tolerance in a natural host-pathogen interaction. | individuals vary in their ability to defend against pathogens. determining how natural selection maintains this variation is often difficult, in part because there are multiple ways that organisms defend themselves against pathogens. one important distinction is between mechanisms of resistance that fight off infection, and mechanisms of tolerance that limit the impact of infection on host fitness without influencing pathogen growth. theory predicts variation among genotypes in resistance, but n ... | 2014 | 24689981 |
| protection against a fungal pathogen conferred by the aphid facultative endosymbionts rickettsia and spiroplasma is expressed in multiple host genotypes and species and is not influenced by co-infection with another symbiont. | many insects harbour facultative endosymbiotic bacteria, often more than one type at a time. these symbionts can have major effects on their hosts' biology, which may be modulated by the presence of other symbiont species and by the host's genetic background. we investigated these effects by transferring two sets of facultative endosymbionts (one hamiltonella and rickettsia, the other hamiltonella and spiroplasma) from naturally double-infected pea aphid hosts into five novel host genotypes of t ... | 2013 | 24118386 |
| unrelated facultative endosymbionts protect aphids against a fungal pathogen. | the importance of microbial facultative endosymbionts to insects is increasingly being recognized, but our understanding of how the fitness effects of infection are distributed across symbiont taxa is limited. in the pea aphid, some of the seven known species of facultative symbionts influence their host's resistance to natural enemies, including parasitoid wasps and a pathogenic fungus. here we show that protection against this entomopathogen, pandora neoaphidis, can be conferred by strains of ... | 2013 | 23137173 |
| automated solution-phase synthesis of insect glycans to probe the binding affinity of pea enation mosaic virus. | pea enation mosaic virus (pemv)--a plant rna virus transmitted exclusively by aphids--causes disease in multiple food crops. however, the aphid-virus interactions required for disease transmission are poorly understood. for virus transmission, pemv binds to a heavily glycosylated receptor aminopeptidase n in the pea aphid gut and is transcytosed across the gut epithelium into the aphid body cavity prior to release in saliva as the aphid feeds. to investigate the role of glycans in pemv-aphid int ... | 2015 | 26457763 |
| in vitro evidence supports membrane alanyl aminopeptidase n as a receptor for a plant virus in the pea aphid vector. | insect-borne plant viruses cause significant agricultural losses and jeopardize sustainable global food production. although blocking plant virus transmission would allow for crop protection, virus receptors in insect vectors are unknown. here we identify membrane alanyl aminopeptidase n (apn) as a receptor for pea enation mosaic virus (pemv) coat protein (cp) in the gut of the pea aphid, acyrthosiphon pisum, using a far-western blot method. pulldown and immunofluorescence binding assays and sur ... | 2015 | 26311872 |
| role of pea enation mosaic virus coat protein in the host plant and aphid vector. | understanding the molecular mechanisms involved in plant virus-vector interactions is essential for the development of effective control measures for aphid-vectored epidemic plant diseases. the coat proteins (cp) are the main component of the viral capsids, and they are implicated in practically every stage of the viral infection cycle. pea enation mosaic virus 1 (pemv1, enamovirus, luteoviridae) and pea enation mosaic virus 2 (pemv2, umbravirus, tombusviridae) are two rna viruses in an obligate ... | 2016 | 27869713 |
| monitoring of aphid flight activities in seed potato crops in serbia. | aphid flight activities in seed potato fields have been studied by the yellow water traps. it is a good method for monitoring aphids as vectors of viruses, but this study also showed it is a suitable method for insect-diversity research. during the four-year studies, over 11.500 specimens were collected and a total of 107 different taxa of aphids were identified. the most abundant species were polyphagous species, such as: acyrthosiphon pisum (haris), aphis fabae scopoli, aphis gossypii gloveran ... | 2013 | 24039529 |
| a recombinant fusion protein containing a spider toxin specific for the insect voltage-gated sodium ion channel shows oral toxicity towards insects of different orders. | recombinant fusion protein technology allows specific insecticidal protein and peptide toxins to display activity in orally-delivered biopesticides. the spider venom peptide δ-amaurobitoxin-pi1a, which targets insect voltage-gated sodium channels, was fused to the "carrier" snowdrop lectin (gna) to confer oral toxicity. the toxin itself (pi1a) and an amaurobitoxin/gna fusion protein (pi1a/gna) were produced using the yeast pichia pastoris as expression host. although both proteins caused mortali ... | 2014 | 24486516 |
| diversity, frequency and geographic distribution of facultative bacterial endosymbionts in introduced aphid pests. | facultative bacterial endosymbionts in insects have been under intense study during the last years. endosymbionts can modify the insect's phenotype, conferring adaptive advantages under environmental stress. this seems particularly relevant for a group of worldwide agricultural aphid pests, because endosymbionts modify key fitness related traits, including host plant use, protection against natural enemies and heat tolerance. aimed to understand the role of facultative endosymbionts on the succe ... | 2016 | 26773849 |
| inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes. | herbivorous insects frequently harbor bacterial symbionts that affect their ecology and evolution. aphids host the obligatory endosymbiont buchnera, which is required for reproduction, together with facultative symbionts whose frequencies vary across aphid populations. these maternally transmitted secondary symbionts have been particularly studied in the pea aphid, acyrthosiphon pisum, which harbors at least 8 distinct bacterial species (not counting buchnera) having environmentally dependent ef ... | 2014 | 24382700 |
| rhodnius prolixus supergene families of enzymes potentially associated with insecticide resistance. | chagas disease or american trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite, trypanosoma cruzi. once known as an endemic health problem of poor rural populations in latin american countries, it has now spread worldwide. the parasite is transmitted by triatomine bugs, of which rhodnius prolixus (hemiptera, reduviidae, triatominae) is one of the vectors and a model organism. this species occurs mainly in central and south american countries where the dise ... | 2016 | 26079630 |
| effects of a protease inhibitor protein from xenorhabdus bovienii on physiology of pea aphid (acyrthosiphon pisum). | the effects of a protease inhibitor protein from xenorhabdus bovienii strain xbi1 (xbpi-1) on biochemistry and physiology of pea aphid (acyrthosiphon pisum) were studied, and the effects of xbpi-1 on the activities of aphid aminopeptidase and the concentrations of carbohydrates, free amino acids and lipids in a. pisum were determined. the results showed that the activity of aminopeptidase was reduced 18.30% by xbpi-1 in vitro assays. in addition, the total sugar, glycogen, and lipid concentratio ... | 2014 | 24485320 |
| a new gene from xenorhabdus bovienii and its encoded protease inhibitor protein against acyrthosiphon pisum. | aphids are insect pests with significant importance worldwide for agricultural and horticultural crops. the chemical pesticides used to control aphids could result in pesticide residues in agricultural and horticultural products as well as in negative effects on the environment. therefore, alternative control methods are urgently needed. this study identified a new gene from strain bjfs526 of the symbiotic bacterium xenorhabdus bovienii and expressed the protease inhibitor protein encoded by the ... | 2012 | 22566467 |
| identification of potential early regulators of aphid resistance in medicago truncatula via transcription factor expression profiling. | *resistance to aphids has been identified in a number of plant species, yet the molecular mechanisms underlying aphid resistance remain largely unknown. *using high-throughput quantitative real-time pcr technology, the transcription profiles of 752 putative medicago truncatula transcription factor genes were analysed in a pair of susceptible and resistant closely related lines of m. truncatula following 6 and 12 h of bluegreen aphid (acyrthosiphon kondoi) infestation. *eighty-two transcription f ... | 2010 | 20345634 |
| a single gene, ain, in medicago truncatula mediates a hypersensitive response to both bluegreen aphid and pea aphid, but confers resistance only to bluegreen aphid. | biotic stress in plants frequently induces a hypersensitive response (hr). this distinctive reaction has been studied intensively in several pathosystems and has shed light on the biology of defence signalling. compared with microbial pathogens, relatively little is known about the role of the hr in defence against insects. reference genotype a17 of medicago truncatula gaertn., a model legume, responds to aphids of the genus acyrthosiphon with necrotic lesions resembling a hr. in this study, the ... | 2009 | 19690018 |
| 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 |
| multi-modal defenses in aphids offer redundant protection and increased costs likely impeding a protective mutualism. | 1.the pea aphid, acyrthosiphon pisum, maintains extreme variation in resistance to its most common parasitoid wasp enemy, aphidius ervi, which is sourced from two known mechanisms: protective bacterial symbionts, most commonly hamiltonella defensa, or endogenously encoded defenses. we have recently found that individual aphids may employ each defense individually, occasionally both defenses together, or neither. 2.in field populations, hamiltonella-infected aphids are found at low to moderate fr ... | 2017 | 28378393 |
| afidopyropen: new and potent modulator of insect transient receptor potential channels. | the commercial insecticides pymetrozine and pyrifluquinazon control plant-sucking pests by disturbing their coordination and ability to feed. we have previously shown that these compounds act by overstimulating and eventually silencing vanilloid-type transient receptor potential (trpv) channels, which consist of two proteins, nanchung and inactive, that are co-expressed exclusively in insect chordotonal stretch receptor neurons. here we show that a new insecticidal compound, afidopyropen, modula ... | 2017 | 28347703 |
| efficacy of rna interference knockdown using aerosolized short interfering rnas bound to nanoparticles in three diverse aphid species. | rna interference (rnai) has emerged as a promising method for validating gene function; however, its utility in nonmodel insects has proven problematic, with delivery methods being one of the main obstacles. this study investigates a novel method of rnai delivery in aphids, the aerosolization of short interfering rna (sirna)-nanoparticle complexes. by using nanoparticles as a sirna carrier, the likelihood of cellular uptake is increased, when compared to methods previously used in insects. to de ... | 2017 | 28314050 |
| secondary metabolites from the endophytic fungus talaromyces pinophilus. | endophytic fungi have a great influence on plant health and growth, and are an important source of bioactive natural compounds. organic extracts obtained from the culture filtrate of an endophytic strain of talaromyces pinophilus isolated from strawberry tree (arbutus unedo) were studied. metabolomic analysis revealed the presence of three bioactive metabolites, the siderophore ferrirubin, the platelet-aggregation inhibitor herquline b and the antibiotic 3-o-methylfunicone. the latter was the ma ... | 2017 | 28278635 |
| turning in mid-air allows aphids that flee the plant to avoid reaching the risky ground. | when forced to drop from the plant, flightless arboreal insects can avoid reaching the risky ground by maneuvering their body through the air. when wingless pea aphids (acyrthosiphon pisum) are threatened by natural enemies, they often drop off their host plant while assuming a stereotypic posture that rotates them in mid-air, aligning them with their feet pointing downwards. this position may increase their chances to re-cling onto lower plant parts and avoid facing the dangers on the ground, t ... | 2017 | 28261994 |
| genotype specificity among hosts, pathogens, and beneficial microbes influences the strength of symbiont-mediated protection. | the microbial symbionts of eukaryotes influence disease resistance in many host-parasite systems. symbionts show substantial variation in both genotype and phenotype, but it is unclear how natural selection maintains this variation. it is also unknown whether variable symbiont genotypes show specificity with the genotypes of hosts or parasites in natural populations. genotype by genotype interactions are a necessary condition for coevolution between interacting species. uncovering the patterns o ... | 2017 | 28252804 |
| characterisation, analysis of expression and localisation of circadian clock genes from the perspective of photoperiodism in the aphid acyrthosiphon pisum. | aphids are typical photoperiodic insects that switch from viviparous parthenogenetic reproduction typical of long day seasons to oviparous sexual reproduction triggered by the shortening of photoperiod in autumn yielding an overwintering egg in which an embryonic diapause takes place. while the involvement of the circadian clock genes in photoperiodism in mammals is well established, there is still some controversy on their participation in insects. the availability of the genome of the pea aphi ... | 2017 | 28235563 |
| life-history strategy determines constraints on immune function. | determining the factors governing investment in immunity is critical to understanding host-pathogen ecological and evolutionary dynamics. studies often consider disease resistance in the context of life-history theory, with the expectation that investment in immunity will be optimized in anticipation of disease risk. immunity, however, is constrained by context-dependent fitness costs. how the costs of immunity vary across life-history strategies has yet to be considered. pea aphids are typicall ... | 2017 | 28211052 |
| the dynamics of the defense strategy of pea induced by exogenous nitric oxide in response to aphid infestation. | the aim of this study was to investigate the effect of exogenous nitric oxide (no), i.e., s-nitrosoglutathione (gsno) and sodium nitroprusside (snp), on the metabolic status of pisum sativum l. cv. cysterski leaves infested by acyrthosiphon pisum harris, population demographic parameters and a. pisum feeding activity. a reduction in the level of semiquinone radicals in pea seedling leaves pretreated with exogenous no occurred 24 h after a. pisum infestation, which was earlier than in non-pretrea ... | 2017 | 28165429 |
| aphid heritable symbiont exploits defensive mutualism. | insects and other animals commonly form symbioses with heritable bacteria, which can exert large influences on host biology and ecology. the pea aphid, acyrthosiphon pisum, is a model for studying effects of infection with heritable facultative symbionts (hfs), and each of its seven common hfs species has been reported to provide resistance to biotic or abiotic stresses. however, one common hfs, called x-type, rarely occurs as a single infection in field populations and instead typically superin ... | 2017 | 28159793 |
| chemical composition and behavioral effects of five plant essential oils on the green pea aphid acyrthosiphon pisum (harris) (homoptera: aphididae). | essential oils (eos) from schinus molle, helichrysum gymnocephalum, cedrelopsis grevei and melaleuca viridiflora, four aromatic and medicinal plants, are commonly used in folk medicine. eos were characterized by gas chromatography-mass spectrometry (gc-ms) and quantified by gas chromatography-flame ionization detection (gc-fid); then evaluated for their behavioral effects on adults of the green pea aphid acyrthosiphon pisum (harris) using a perspex four-armed olfactometer in order to test the co ... | 2017 | 28122144 |
| a case for a joint strategy of diversified bet hedging and plasticity in the pea aphid wing polyphenism. | phenotypic plasticity and diversified bet hedging are strategies for coping with variable environments. plasticity is favoured when an organism can predict future conditions using environmental cues, while bet hedging is favoured when predictive cues are not available. theoretical analyses suggest that many organisms should use a mixture of both strategies, because environments often present both scenarios. here, we examine if the pea aphid wing polyphenism, a well-known case of plasticity, is p ... | 2016 | 28120801 |
| whole genome sequence of the soybean aphid, aphis glycines. | aphids are emerging as model organisms for both basic and applied research. of the 5,000 estimated species, only three aphids have published whole genome sequences: the pea aphid acyrthosiphon pisum, the russian wheat aphid, diuraphis noxia, and the green peach aphid, myzus persicae. we present the whole genome sequence of a fourth aphid, the soybean aphid (aphis glycines), which is an extreme specialist and an important invasive pest of soybean (glycine max). the availability of genomic resourc ... | 2017 | 28119199 |
| ecdysone signaling underlies the pea aphid transgenerational wing polyphenism. | the wing polyphenism of pea aphids is a compelling laboratory model with which to study the molecular mechanisms underlying phenotypic plasticity. in this polyphenism, environmental stressors such as high aphid density cause asexual, viviparous adult female aphids to alter the developmental fate of their embryos from wingless to winged morphs. this polyphenism is transgenerational, in that the pea aphid mother experiences the environmental signals, but it is her offspring that are affected. prev ... | 2017 | 28115695 |
| elevated carbon dioxide concentration reduces alarm signaling in aphids. | insects often rely on olfaction to communicate with conspecifics. while the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (e)-β-farnesene (eβf), (2) em ... | 2017 | 28097605 |
| corrigendum: optimization of agroinfiltration in pisum sativum provides a new tool for studying the salivary protein functions in the pea aphid complex. | [this corrects the article on p. 1171 in vol. 7, pmid: 27555856.]. | 2016 | 28077941 |
| aphid specialization on different summer hosts is associated with strong genetic differentiation and unequal symbiont communities despite a common mating habitat. | specialization on different host plants can promote evolutionary diversification of herbivorous insects. work on pea aphids (acyrthosiphon pisum) has contributed significantly to the understanding of this process, demonstrating that populations associated with different host plants exhibit performance trade-offs across hosts, show adaptive host choice and genetic differentiation and possess different communities of bacterial endosymbionts. populations specialized on different secondary host plan ... | 2017 | 28055138 |
| interactions of the asian lady beetle, harmonia axyridis (coleoptera: coccinellidae), and the north american native lady beetle, coccinella novemnotata (coleoptera: coccinellidae): prospects for recovery post-decline. | the decline of the north american native lady beetle, coccinella novemnotata herbst, is strongly correlated with the introduction of coccinella septempunctata l., and c. novemnotata are locally extirpated across much of the united states. since c. novemnotata's decline, the invasive harmonia axyridis pallas has become dominant in north america. this study investigated whether h. axyridis has the potential to impede the recovery of c. novemnotata populations. to determine how h. axyridis interact ... | 2017 | 28049630 |
| mechanisms underlying the nonconsumptive effects of parasitoid wasps on aphids. | natural enemies need not consume herbivores to suppress herbivore populations. behavioral interactions can adversely impact herbivore fitness from reduced time feeding, investment in defense, or injury from failed attacks. the importance of such "nonconsumptive effects" for herbivore suppression may vary across species based on the specificity and intensity of the herbivore defensive response. in a series of manipulative studies, we quantified the nature and consequences of nonconsumptive intera ... | 2017 | 28025222 |
| deciphering the function of octopaminergic signaling on wing polyphenism of the pea aphid acyrthosiphon pisum. | aphids exhibit wing polyphenism (winged or wingless) for adaption to predictable or temporally heterogeneous environmental changes; however, the underlying mechanism is still unclear. this morphological change could be stimulated by high aphid density, which in turn could affect octopaminergic signaling in aphids. octopamine is a neurotransmitter synthesized in insects that can modify their physiological metabolism, locomotion, and other behaviors. we designed experiments to determine whether oc ... | 2016 | 28018234 |
| molecular basis of alarm pheromone detection in aphids. | the sesquiterpene (e)-β-farnesene (ebf) is the alarm pheromone for many species of aphids [1]. when released from aphids attacked by parasitoids or predators, it alerts nearby conspecifics to escape by walking away and dropping off the host plant [2, 3]. the reception of alarm pheromone in aphids is accomplished through a highly sensitive chemosensory system. although olfaction-related gene families including odorant receptors (ors) and odorant-binding proteins (obps) have recently been identifi ... | 2017 | 27916525 |
| the microrna toolkit of insects. | is there a correlation between mirna diversity and levels of organismic complexity? exhibiting extraordinary levels of morphological and developmental complexity, insects are the most diverse animal class on earth. their evolutionary success was in particular shaped by the innovation of holometabolan metamorphosis in endopterygotes. previously, mirna evolution had been linked to morphological complexity, but astonishing variation in the currently available mirna complements of insects made this ... | 2016 | 27883064 |
| insect and plant-derived mirnas in greenbug (schizaphis graminum) and yellow sugarcane aphid (sipha flava) revealed by deep sequencing. | schizaphis graminum (green bug; gb) and sipha flava (yellow sugarcane aphid; ysa) are two cereal aphid species with broad host ranges capable of establishing on sorghum (sorghum bicolor) and several switchgrass (panicum virgatum) cultivars. switchgrass and sorghum are staple renewable bioenergy crops that are vulnerable to damage by aphids, therefore, identifying novel targets to control aphids has the potential to drastically improve yields and reduce losses in these bioenergy crops. despite th ... | 2017 | 27838454 |
| characterization of an insect heterodimeric voltage-gated sodium channel with unique alternative splicing mode. | recent discovery of the heterodimeric voltage-gated sodium channels (nav) in two aphid species, acyrthosiphon pisum and myzus persicae, aroused interest in exploring whether this kind of channel is conserved for aphids. herewith, we aim to provide evidence for the conservation of heterodimeric navs in aphids and investigate whether they have unique splicing patterns. we found that the only identifiable nav from toxoptera citricida consisted of two subunits, forming a heterodimeric nav, which car ... | 2017 | 27816572 |
| post-reproductive parthenogenetic pea aphids (acyrthosiphon pisum) are visually identifiable and disproportionately positioned distally to clonal colonies. | the role of kin-selection in the evolution of post-reproductive life is controversial. while anthropological and demographic studies strongly suggest that humans and a few other species experience kin selection for significant post-reproductive survival, these results are necessarily correlational. understanding could therefore be advanced by the development of a globally available, field and laboratory tractable experimental model of kin-selected post-reproductive survival. in only one inverteb ... | 2016 | 27812427 |
| genomic and cytogenetic localization of the carotenoid genes in the aphid genome. | data published in the scientific literature suggests a possible link between chromosomal rearrangements involving autosomes 1 and 3 and the presence of red morphs in the peach-potato aphid myzus persicae (sulzer). in order to begin a study of this relationship, we analysed the genomic and chromosomal location of genes involved in carotenoid biosynthesis in m. persicae and the pea aphid, acyrthosiphon pisum (harris), since carotenoids are the basis of the colour in many aphid species. genomic ana ... | 2016 | 27585067 |
| heat shock protein 83 plays pleiotropic roles in embryogenesis, longevity, and fecundity of the pea aphid acyrthosiphon pisum. | heat shock protein 83 (hsp83) is homologous to the chaperone hsp90. it has pleiotropic functions in drosophila melanogaster, including the control of longevity and fecundity, and facilitates morphological evolution by buffering cryptic deleterious mutations in wild populations. in the pea aphid acyrthosiphon pisum, hsp83 expression is moderately induced by bacterial infection but upregulated more strongly in response to heat stress and fungal infection. stress-inducible heat shock proteins are o ... | 2017 | 27743033 |
| dropping behavior in the pea aphid (hemiptera: aphididae): how does environmental context affect antipredator responses? | the pea aphid acyrthosiphon pisum : harris (hemiptera: aphididae) is a phloem-feeding insect whose antipredator defenses include kicking, walking away, and dropping from the plant. aphid dropping, a risky and energetically costly antipredator behavior, can be increased by the release of aphid alarm pheromone; there is also evidence that insect density and plant health can affect the likelihood of aphids engaging in this behavior. we investigated whether interactions between alarm cues, insect de ... | 2016 | 27638950 |
| strategies used by two apterous strains of the pea aphid acyrthosiphon pisum for passive dispersal. | wingless forms of aphids are relatively sedentary, and have a limited ability to migrate or disperse. however, they can drop off hosts or walk away if disturbed, or their food quality or quantity become deteriorated. earlier, we found that the pea aphid, acyrthosiphon pisum (harris, 1776), could use differed strategies to escape danger and locate new host plants. to determine the mechanisms behind the different strategies, we undertook a series of studies including the aphids' host location, ene ... | 2016 | 27628035 |
| systemic stereoselectivity study of flufiprole: stereoselective bioactivity, acute toxicity and environmental fate. | in this study, the stereoselectivity of flufiprole enantiomers in regards to their bioactivity, acute toxicity and environmental fate is reported for the first time. four types of representative insects (plutella xylostella, nilaparvata lugens, mythimna separata and acyrthosiphon pisum) were used to investigate enantioselective bioactivity. acute toxicities of flufiprole enantiomers toward two non-target organisms were also evaluated. moreover, stereoselective degradation in four vegetables unde ... | 2016 | 27585281 |
| optimization of agroinfiltration in pisum sativum provides a new tool for studying the salivary protein functions in the pea aphid complex. | aphids are piercing-sucking insect pests and feed on phloem sap. during feeding, aphids inject a battery of salivary proteins into host plant. some of these proteins function like effectors of microbial pathogens and influence the outcome of plant-aphid interactions. the pea aphid (acyrthosiphon pisum) is the model aphid and encompasses multiple biotypes each specialized to one or a few legume species, providing an opportunity to investigate the underlying mechanisms of the compatibility between ... | 2016 | 27555856 |
| targeted re-sequencing confirms the importance of chemosensory genes in aphid host race differentiation. | host-associated races of phytophagous insects provide a model for understanding how adaptation to a new environment can lead to reproductive isolation and speciation, ultimately enabling us to connect barriers to gene flow to adaptive causes of divergence. the pea aphid (acyrthosiphon pisum) comprises host races specializing on legume species and provides a unique system for examining the early stages of diversification along a gradient of genetic and associated adaptive divergence. as host choi ... | 2017 | 27552184 |
| dropping behaviour of pea aphid nymphs increases their development time and reduces their reproductive capacity as adults. | background. many aphid species, including the pea aphid acyrthosiphon pisum, exhibit a behaviour where they drop or fall from their host plant, a commonly used strategy to avoid predation, parasitism or physical disturbance. we hypothesised that there was a physiological non-consumptive cost due to such dropping behaviour because aphids would expend energy re-establishing themselves on a host plant and also lose feeding time. methods. we evaluated this non-consumptive cost by determining the dev ... | 2016 | 27547545 |
| winged pea aphids can modify phototaxis in different development stages to assist their host distribution. | the pea aphid, acyrthosiphon pisum (harris) (hemiptera: aphididae), shows wing polyphenism (winged and wingless morphs) in its life cycle. the winged morph is adapted for dispersal; its two developmental adult stages (for dispersal and reproduction) are based on its breeding periods. the two morphs show different phototactic behavior and the winged can change its preference to light according to the developmental stages. to determine the mechanism and ecological functions of phototaxis for a. pi ... | 2016 | 27531980 |
| consequences of coinfection with protective symbionts on the host phenotype and symbiont titres in the pea aphid system. | symbiotic associations between microbes and insects are widespread, and it is frequent that several symbionts share the same host individual. hence, interactions can occur between these symbionts, influencing their respective abundance within the host with consequences on its phenotype. here, we investigate the effects of multiple infections in the pea aphid, acyrthosiphon pisum, which is the host of an obligatory and several facultative symbionts. in particular, we study the influence of a coin ... | 2016 | 27514019 |
| genetic mapping of a major resistance gene to pea aphid (acyrthosipon pisum) in the model legume medicago truncatula. | resistance to the australian pea aphid (pa; acyrthosiphon pisum) biotype in cultivar jester of the model legume medicago truncatula is mediated by a single dominant gene and is phloem-mediated. the genetic map position for this resistance gene, apr (acyrthosiphon pisum resistance), is provided and shows that apr maps 39 centimorgans (cm) distal of the a. kondoi resistance (akr) locus, which mediates resistance to a closely related species of the same genus bluegreen aphid (a. kondoi). the apr re ... | 2016 | 27483247 |
| glucosinolates from host plants influence growth of the parasitic plant cuscuta gronovii and its susceptibility to aphid feeding. | parasitic plants acquire diverse secondary metabolites from their hosts, including defense compounds that target insect herbivores. however, the ecological implications of this phenomenon, including the potential enhancement of parasite defenses, remain largely unexplored. we studied the translocation of glucosinolates from the brassicaceous host plant arabidopsis (arabidopsis thaliana) into parasitic dodder vines (convolvulaceae; cuscuta gronovii) and its effects on the parasite itself and on d ... | 2016 | 27482077 |
| differential gene expression according to race and host plant in the pea aphid. | host-race formation in phytophagous insects is thought to provide the opportunity for local adaptation and subsequent ecological speciation. studying gene expression differences amongst host races may help to identify phenotypes under (or resulting from) divergent selection and their genetic, molecular and physiological bases. the pea aphid (acyrthosiphon pisum) comprises host races specializing on numerous plants in the fabaceae and provides a unique system for examining the early stages of div ... | 2016 | 27474484 |
| foxl2 and its relatives are evolutionary conserved players in gonadal sex differentiation. | foxl2 is a member of the large family of forkhead box (fox) domain transcription factors. it emerged during the last 15 years as a key player in ovarian differentiation and oogenesis in vertebrates and especially mammals. this review focuses on foxl2 genes in light of recent findings on their evolution, expression, and implication in sex differentiation in animals in general. homologs of foxl2 and its paralog foxl3 are found in all metazoans, but their gene evolution is complex, with multiple ga ... | 2016 | 27441599 |
| cytochrome p450 gene, cyp4g51, modulates hydrocarbon production in the pea aphid, acyrthosiphon pisum. | terrestrial insects deposit a layer of hydrocarbons (hcs) as waterproofing agents on their epicuticle. the insect-specific cyp4g genes, subfamily members of p450, have been found in all insects with sequenced genomes to date. they are critical for hc biosynthesis in drosophila; however, their functional roles in other insects including the piercing-sucking hemipterous aphids remain unknown. in this study, we presented the molecular characterization and a functional study of the cyp4g51 gene in t ... | 2016 | 27425674 |
| the genomewide transcriptional response underlying the pea aphid wing polyphenism. | phenotypic plasticity is a key life history strategy used by many plants and animals living in heterogeneous environments. a multitude of studies have investigated the costs and limits of plasticity, as well as the conditions under which it evolves. much less well understood are the molecular genetic mechanisms that enable an organism to sense its environment and respond in a plastic manner. the pea aphid wing polyphenism is a compelling laboratory model to study these mechanisms. in this polyph ... | 2016 | 27393739 |
| hoverfly preference for high honeydew amounts creates enemy-free space for aphids colonizing novel host plants. | the existence of an enemy-free space can play an important role in aphid host race formation processes, but little is known about the mechanisms that create an area of low predation pressure on particular host plants. in this paper, we identify a mechanism generating lower predation pressure that promotes the maintenance of the different host races of the pea aphid (acyrthosiphon pisum) complex, a well-studied model for ecological speciation. the pea aphid consists of at least 15 genetically dis ... | 2016 | 27328648 |