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Takema Fukatsu - One of the best experts on this subject based on the ideXlab platform.

  • Genome Analysis of "Candidatus Regiella insecticola" Strain TUt, Facultative Bacterial Symbiont of the Pea Aphid Acyrthosiphon pisum.
    Microbiology resource announcements, 2020
    Co-Authors: Naruo Nikoh, Ryuichi Koga, Tsutomu Tsuchida, Masahira Hattori, Kenshiro Oshima, Takema Fukatsu
    Abstract:

    ABSTRACT The genome of “Candidatus Regiella insecticola” strain TUt, a facultative bacterial symbiont of the pea aphid Acyrthosiphon pisum, was analyzed. We determined a 2.5-Mb draft genome consisting of 14 contigs; this will contribute to the understanding of the symbiont, which underpins various ecologically adaptive traits of the host insect.

  • genome sequence of candidatus serratia symbiotica strain is a facultative bacterial symbiont of the pea aphid Acyrthosiphon pisum
    Microbiology resource announcements, 2019
    Co-Authors: Naruo Nikoh, Ryuichi Koga, Masahira Hattori, Takema Fukatsu, Kenshiro Oshima
    Abstract:

    ABSTRACT “Candidatus Serratia symbiotica” is a facultative bacterial symbiont of aphids that affects various ecological traits of the host insects. Here, we report the complete genome sequence of “Candidatus Serratia symbiotica” strain IS, consisting of a 2,736,352-bp chromosome and an 82,605-bp plasmid, from the pea aphid Acyrthosiphon pisum.

  • a full length cdna resource for the pea aphid Acyrthosiphon pisum
    Insect Molecular Biology, 2010
    Co-Authors: Stephen Richards, Andrew Cree, Mizue Morioka, Shuji Shigenobu, Toshiaki Kudo, Takema Fukatsu, Richard A. Gibbs, Shin-ya Miyagishima, David L. Stern
    Abstract:

    Large collections of full-length cDNAs are important resources for genome annotation and functional genomics. We report the creation of a collection of 50 599 full-length cDNA clones from the pea aphid, Acyrthosiphon pisum. Sequencing from 5′ and 3′ ends of the clones generated 97 828 high-quality expressed sequence tags, representing approximately 9000 genes. These sequences were imported to AphidBase and are shown to play crucial roles in both automatic gene prediction and manual annotation. Our detailed analyses demonstrated that the full-length cDNAs can further improve gene models and can even identify novel genes that are not included in the current version of the official gene set. This full-length cDNA collection can be utilized for a wide variety of functional studies, serving as a community resource for the study of the functional genomics of the pea aphid.

  • 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
    Applied and Environmental Microbiology, 2007
    Co-Authors: T L Wilkinson, Ryuichi Koga, Takema Fukatsu
    Abstract:

    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.

  • characterization of a facultative endosymbiotic bacterium of the pea aphid Acyrthosiphon pisum
    Microbial Ecology, 2005
    Co-Authors: Ryuichi Koga, Xianying Meng, T Tsuchida, Tadao Matsumoto, Takema Fukatsu
    Abstract:

    The pea aphid U-type symbiont (PAUS) was investigated to characterize its microbiological properties. Fluorescence in situ hybridization (FISH) and electron microscopy revealed that PAUS was a rod-shaped bacterium found in three different locations in the body of the pea aphid Acyrthosiphon pisum: sheath cells, secondary mycetocytes, and hemolymph. Artificial transfer experiments revealed that PAUS could establish stable infection and vertical transmission when introduced into uninfected pea aphids. When 28 aphid species collected in Japan were subjected to a diagnostic PCR assay, four species of the subfamily Aphidinae (Aphis citricola, Aphis nerii, Macrosiphum avenae, and Uroleucon giganteus) and a species of the subfamily Pemphiginae (Colopha kansugei) were identified to be PAUS-positive. The sporadic incidences of PAUS infection without reflecting the aphid phylogeny can be best explained by occasional horizontal transfers of the symbiont across aphid lineages.

Ryuichi Koga - One of the best experts on this subject based on the ideXlab platform.

Angela E Douglas - One of the best experts on this subject based on the ideXlab platform.

  • the physiology of sterol nutrition in the pea aphid Acyrthosiphon pisum
    Journal of Insect Physiology, 2012
    Co-Authors: Sophie Bouvaine, Spencer T Behmer, Marieline Faure, Robert J. Grebenok, Angela E Douglas
    Abstract:

    The phloem sap of fava bean (Vicia faba) plants utilized by the pea aphid Acyrthosiphon pisum contains three sterols, cholesterol, stigmasterol and sitosterol, in a 2:2:1 ratio. To investigate the nutritional value of these sterols, pea aphids were reared on chemically-defined diets containing each sterol at 0.1, 1 and 10 μg ml−1 with a sterol-free diet as control. Larval growth rate and aphid lifespan did not vary significantly across the diets, indicating that sterol reserves can buffer some performance indices against a shortfall in dietary sterol over at least one generation. However, lifetime reproductive output was depressed in aphids on diets containing stigmasterol or no sterol, relative to diets supplemented with cholesterol or sitosterol. The cholesterol density of embryos in teneral adults was significantly higher than in the total body; and the number and biomass of embryos in aphids on diets with stigmasterol and no sterols were reduced relative to diets with cholesterol or sitosterol, indicating that the reproductive output of the pea aphid can be limited by the amount and composition of dietary sterol. In a complementary RNA-seq analysis of pea aphids reared on plants and diets with different sterol contents, 7.6% of the 17,417 detected gene transcripts were differentially expressed. Transcript abundance of genes with annotated function in sterol utilization did not vary significantly among treatments, suggesting that the metabolic response to dietary sterol may be mediated primarily at the level of enzyme function or metabolite concentration.

  • Acyrthosiphon pisum aqp2 a multifunctional insect aquaglyceroporin
    Biochimica et Biophysica Acta, 2012
    Co-Authors: Ally J Shakesby, Angela E Douglas, Jin Ha Hwang, Won Gyu Choi, Natalia Martinkova
    Abstract:

    Annotation of the recently sequenced genome of the pea aphid (Acyrthosiphon pisum) identified a gene ApAQP2 (ACYPI009194, Gene ID: 100168499) with homology to the Major Intrinsic Protein/aquaporin superfamily of membrane channel proteins. Phylogenetic analysis suggests that ApAQP2 is a member of an insect-specific clade of this superfamily. Homology model structures of ApAQP2 showed a novel array of amino acids comprising the substrate selectivity-determining “aromatic/arginine” region of the putative transport pore. Subsequent characterization of the transport properties of ApAQP2 upon expression in Xenopus oocytes supports an unusual substrate selectivity profile. Water permeability analyses show that the ApAQP2 protein exhibits a robust mercury-insensitive aquaporin activity. However unlike the water-specific ApAQP1 protein, ApAQP2 forms a multifunctional transport channel that shows a wide permeability profile to a range of linear polyols, including the potentially biologically relevant substrates glycerol, mannitol and sorbitol. Gene expression analysis indicates that ApAQP2 is highly expressed in the insect bacteriocytes (cells bearing the symbiotic bacteria Buchnera) and the fat body. Overall the results demonstrate that ApAQP2 is a novel insect aquaglyceroporin which may be involved in water and polyol transport in support of the Buchnera symbiosis and aphid osmoregulation.

  • the secreted salivary proteome of the pea aphid Acyrthosiphon pisum characterised by mass spectrometry
    Proteomics, 2009
    Co-Authors: James C Carolan, Angela E Douglas, Carol I J Fitzroy, Peter D Ashton, T L Wilkinson
    Abstract:

    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 five proteins are not homologous to any previously described sequence and included an abundant salivary protein (represented by ACYPI009881), with a predicted length of 1161 amino acids and high serine, tyrosine and cysteine content. A. pisum feeds on plant phloem sap and the metalloproteases and regucalcin (a putative calcium-binding protein) are predicted determinants of sustained feeding, by inactivation of plant protein defences and inhibition of calcium-mediated occlusion of phloem sieve elements, respectively. The amino acid composition of ACYPI009881 suggests a role in the aphid salivary sheath that protects the aphid mouthparts from plant defences, and the oxidoreductase may promote gelling of the sheath protein or mediate oxidative detoxification of plant allelochemicals. Further salivary proteins are expected to be identified as more sensitive MS technologies are developed.

  • molecular characterisation of a candidate gut sucrase in the pea aphid Acyrthosiphon pisum
    Insect Biochemistry and Molecular Biology, 2007
    Co-Authors: Daniel R G Price, D A Ashford, Harry V Isaacs, Mary Elizabeth Pownall, John A. Gatehouse, Alison J Karley, Hillary S Wilkinson, Angela E Douglas
    Abstract:

    The hydrolysis of sucrose, the principal dietary source of carbon for aphids, is catalysed by a gut α-glucosidase/transglucosidase activity. An α-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 (mature protein). It has amino acid sequence similarity to α-glucosidases (EC 3.2.1.20) of glycoside hydrolase family 13 in other insects. The predicted APS1 protein contains two domains: an N-terminal catalytic domain, and a C-terminal hydrophobic domain. In situ localisation and RT-PCR studies revealed that APS1 mRNA was expressed in the gut distal to the stomach, the same localisation as sucrase activity. When expressed heterologously in Xenopus embryos, APS1 was membrane-bound and had sucrase activity. It is concluded that APS1 is a dominant, and possibly sole, protein mediating sucrase activity in the aphid gut.

  • facultative secondary bacterial symbionts and the nutrition of the pea aphid Acyrthosiphon pisum
    Physiological Entomology, 2006
    Co-Authors: Angela E Douglas, C L M J Francois, L B Minto
    Abstract:

    Facultative ‘secondary’ bacterial symbionts influence various traits of aphids, including plant utilization patterns and resistance to parasitoids. The present study is designed to test the hypothesis that these multiple effects are underlain by symbiont-mediated changes to the aphid requirement for the dominant dietary nutrients, sucrose and amino acids. The performance of pea aphids (Acyrthosiphon pisum) on chemically defined diets of systematically altered sucrose and amino acid content varies among eight parthenogenetic clones, with a pattern that does not match the aphid complements of secondary symbionts, Hamiltonella defensa, Regiella insecticola and Serratia symbiotica. Aphid performance is reduced, increased and unaffected by elimination of S. symbiotica, R. insecticola and H. defensa, respectively, but with no significant effect on the range of diets on which aphids performed well. It is concluded that the impact of secondary symbionts on aphid traits is most unlikely to have a purely nutritional basis.

Wolfgang W. Weisser - One of the best experts on this subject based on the ideXlab platform.

  • juvenile hormone titres and winged offspring production do not correlate in the pea aphid Acyrthosiphon pisum
    Journal of Insect Physiology, 2008
    Co-Authors: Ezra G Schwartzberg, Grit Kunert, Stephanie A Westerlund, Klaus H Hoffmann, Wolfgang W. Weisser
    Abstract:

    Abstract 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 small insects such as aphids. Using a novel LC–MS approach we were able to quantify JH III in pea aphids that were either producing a high proportion of winged morphs among their offspring or mainly unwinged offspring. We measured JH III titres by pooling the hemolymph of 12 or fewer individuals (1 μL hemolymph) treated identically. Levels of JH ranged from 30 to 163 pg/μL. While aphids in the two treatments strongly differed in the proportion of winged morphs among their offspring, their JH III titres did not differ significantly. There was also no correlation between JH III titre and the proportion of winged offspring in induced aphids. This supports earlier findings that wing dimorphism in aphids may be regulated by other physiological mechanisms.

  • alarm pheromone emission by pea aphid Acyrthosiphon pisum clones under predation by lacewing larvae
    Entomologia Experimentalis Et Applicata, 2008
    Co-Authors: Ezra G Schwartzberg, Grit Kunert, Jonathan Gershenzon, Ursula S R Rose, Wolfgang W. Weisser
    Abstract:

    Genetic variation in anti-predator traits has been shown for a variety of species. Aphid alarm pheromone, ( E )- β -farnesene, is released by attacked aphids and causes a variety of behavioral defense reactions in the signal receivers. In pea aphids, Acyrthosiphon pisum Harris (Homoptera: Aphididae), ( E )- β -farnesene mediates the production of winged offspring in the presence of natural enemies. While variation in the propensity for pea aphids to produce winged offspring is well-documented, little quantitative information is available about clonal differences in ( E )- β -farnesene emission or the amount of alarm pheromone released in aphid colonies. We tested the wing induction response of four clones when attacked by a predatory lacewing larva, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and found that three of the four clones increased the proportion of winged offspring under predator attack. We then investigated the emission of aphid alarm pheromone of these clones of pea aphid under attack. Alarm pheromone emission in aphid colonies of initially 25 adults varied from 81.2 to 10 851.0 ng per aphid colony over 24 h. There were no differences between clones in total emission or in emission per consumption event. These results show that there is substantial variability in alarm pheromone emission within clones and that the propensity to produce winged offspring in some clones is not a simple function of the propensity of alarm pheromone production in these clones.

  • real time analysis of alarm pheromone emission by the pea aphid Acyrthosiphon pisum under predation
    Journal of Chemical Ecology, 2008
    Co-Authors: Ezra G Schwartzberg, Grit Kunert, Claudia Stephan, Wilhelm Boland, Jonathan Gershenzon, Anja David, Ursula S R Rose, Wolfgang W. Weisser
    Abstract:

    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)-s-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 a rapid gas chromatography technique (zNose™) to monitor headspace emissions. After an initial burst, EBF volatilization declined exponentially, and detectable amounts were still present after 30 min in most cases. Total emission of EBF averaged 16.33 ± 1.54 ng and ranged from 1.18 to 48.85 ng. Emission was higher in nymphs as compared to adults. No differences between pea aphid life stages were detected for their speed of alarm signal emission in response to lacewing larvae attack. This is the first time that alarm pheromone emission from single aphids has been reported.

  • Density dependence of the alarm pheromone effect in pea aphids, Acyrthosiphon pisum (Sternorrhyncha: Aphididae)
    European Journal of Entomology, 2007
    Co-Authors: Grit Kunert, Janett Trautsch, Wolfgang W. Weisser
    Abstract:

    The aphid alarm pheromone is known to trigger wing induction in pea aphids (Acyrthosiphon pisum). In reaction to alarm pheromone, aphids drop off the plant or walk away. While searching for a new feeding site they repeatedly encounter other members of the aphid colony and this increased contact rate is assumed to be important for wing induction ("pseudo-crowding" hypothesis). Because the encounter rate is a function of aphid colony size, wing induction in aphids in the presence of a predator should be a function of the number of aphids on the plant. We placed two, seven or 13 adult pea aphids on bean plants, and exposed the different-sized colonies to synthetic alarm pheromone to test the density-dependence of predator-induced wing induction. The mean percentage of winged morphs among the offspring produced on the plants ranged from 10 to 80 percent and increased both with aphid number and exposure to alarm pheromone. There was no synergy between aphid number and alarm pheromone exposure indi- cating that both factors are additive. The implications for aphid metapopulation dynamics are discussed.

Gonzalez Gonzalez Mauricio - One of the best experts on this subject based on the ideXlab platform.

  • Caracterización de la resistencia de plantas de guisantes (pisum sativum) a dos biotipos de pulgón del guisante (Acyrthosiphon pisum).
    2020
    Co-Authors: Gonzalez Gonzalez Mauricio
    Abstract:

    [ES] Una de las plagas más importantes del mundo son los pulgones, que atacan numerosas plantas de importancia agronómica. Plantas resistentes de cultivos han surgido como una solución alternativa y sostenible para el uso de plaguicidas contra los pulgones. Esta resistencia puede explicarse como el resultado de una alteración en el comportamiento de estos insectos que afecta principalmente la elección del huésped y el comportamiento de alimentación (antixenosis), o al afectar el desarrollo de la fisiología del pulgón (antibiosis). Para identificar y caracterizar el tipo de resistencia en la interacción pisum sativum-Acyrthosiphon pisum, realizamos dos experimentos. El primero, que compara la actividad de dos biotipos de A. pisum (pulgones rosados y verdes vinculados a diferentes plantas de la raza huésped), comportamiento de alimentación (es decir, hipótesis de antixenosis) a través de la técnica EPG en diferentes plantas de P. sativum (susceptibles y resistentes). En el segundo experimento, se criaron larvas en cada planta durante un período de 8 días para comparar su desarrollo fisiológico a través de una configuración de peso corporal (es decir, hipótesis de antibiosis). Los resultados de este trabajo nos permitieron concluir que la resistencia obtenida en las plantas ensayadas de P. sativum no puede explicarse por un mecanismo de antixenosis para el biotipo verde de A. pisum, al menos en plantas no infestadas durante las primeras 8 horas de contacto con pulgones. Por el contrario, la resistencia generalizada que mostró P. sativum contra el biotipo rosado de A. pisum puede explicarse a través de una antixenosis localizada en el nivel del mesófilo y/o floema, que podría explicar el bajo desarrollo de las larvas expresado como medidas de peso corporal después de 8 días. Esto indica que la resistencia vegetal de estas plantas afectó a cada biotipo de manera diferente.[EN] One of the most important pests worldwide are aphids, which attack numerous plants of agronomic importance. Resistant cultivars of crops have emerged as an alternative and sustainable solution to pesticide use against aphids. This resistance can be explained as the result of an alteration in the behavior of these insects mainly affecting the host choice and feeding behavior (antixenosis), or by affecting the aphid physiology development (antibiosis). To identify and characterize the kind of resistance in pisum sativum-Acyrthosiphon pisum interaction we performed two experiments. The first one, comparing the performance of two biotypes of A. pisum (pink and green aphids linked to different host race plants) feeding behavior (i.e. antixenosis hypothesis) through the EPG technique on different cultivars of P. sativum (susceptible and resistant). In the second experiment, larvae were reared on each cultivar for a period of 8 days to compare their physiology development through a bodyweight setup (i.e. antibiosis hypothesis). The results of this work allowed us to conclude that the resistance on the tested cultivars of P. sativum can t be explained by a mechanism of antixenosis for the green biotype of A. pisum at least on uninfested plants during the first 8 hours of contact with aphids. On the contrary, the generalized resistance that P. sativum displayed against the pink biotype of A. pisum can be explained through an antixenosis located at the mesophyll and/or phloem level, which could reflect the low larval development expressed as bodyweight measurements after 8 days. This indicates that the plant resistance of these cultivars affected each biotype differently.Gonzalez Gonzalez, M. (2019). Caracterización de la resistencia de plantas de guisantes (pisum sativum) a dos biotipos de pulgón del guisante (Acyrthosiphon pisum). http://hdl.handle.net/10251/134060TFG

  • Caracterización de la resistencia de plantas de guisantes (pisum sativum) a dos biotipos de pulgón del guisante (Acyrthosiphon pisum)
    'Universitat Politecnica de Valencia', 2020
    Co-Authors: Gonzalez Gonzalez Mauricio
    Abstract:

    [ES] Una de las plagas más importantes del mundo son los pulgones, que atacan numerosas plantas de importancia agronómica. Plantas resistentes de cultivos han surgido como una solución alternativa y sostenible para el uso de plaguicidas contra los pulgones. Esta resistencia puede explicarse como el resultado de una alteración en el comportamiento de estos insectos que afecta principalmente la elección del huésped y el comportamiento de alimentación (antixenosis), o al afectar el desarrollo de la fisiología del pulgón (antibiosis). Para identificar y caracterizar el tipo de resistencia en la interacción pisum sativum-Acyrthosiphon pisum, realizamos dos experimentos. El primero, que compara la actividad de dos biotipos de A. pisum (pulgones rosados y verdes vinculados a diferentes plantas de la raza huésped), comportamiento de alimentación (es decir, hipótesis de antixenosis) a través de la técnica EPG en diferentes plantas de P. sativum (susceptibles y resistentes). En el segundo experimento, se criaron larvas en cada planta durante un período de 8 días para comparar su desarrollo fisiológico a través de una configuración de peso corporal (es decir, hipótesis de antibiosis). Los resultados de este trabajo nos permitieron concluir que la resistencia obtenida en las plantas ensayadas de P. sativum no puede explicarse por un mecanismo de antixenosis para el biotipo verde de A. pisum, al menos en plantas no infestadas durante las primeras 8 horas de contacto con pulgones. Por el contrario, la resistencia generalizada que mostró P. sativum contra el biotipo rosado de A. pisum puede explicarse a través de una antixenosis localizada en el nivel del mesófilo y/o floema, que podría explicar el bajo desarrollo de las larvas expresado como medidas de peso corporal después de 8 días. Esto indica que la resistencia vegetal de estas plantas afectó a cada biotipo de manera diferente.[EN] One of the most important pests worldwide are aphids, which attack numerous plants of agronomic importance. Resistant cultivars of crops have emerged as an alternative and sustainable solution to pesticide use against aphids. This resistance can be explained as the result of an alteration in the behavior of these insects mainly affecting the host choice and feeding behavior (antixenosis), or by affecting the aphid physiology development (antibiosis). To identify and characterize the kind of resistance in pisum sativum-Acyrthosiphon pisum interaction we performed two experiments. The first one, comparing the performance of two biotypes of A. pisum (pink and green aphids linked to different host race plants) feeding behavior (i.e. antixenosis hypothesis) through the EPG technique on different cultivars of P. sativum (susceptible and resistant). In the second experiment, larvae were reared on each cultivar for a period of 8 days to compare their physiology development through a bodyweight setup (i.e. antibiosis hypothesis). The results of this work allowed us to conclude that the resistance on the tested cultivars of P. sativum can t be explained by a mechanism of antixenosis for the green biotype of A. pisum at least on uninfested plants during the first 8 hours of contact with aphids. On the contrary, the generalized resistance that P. sativum displayed against the pink biotype of A. pisum can be explained through an antixenosis located at the mesophyll and/or phloem level, which could reflect the low larval development expressed as bodyweight measurements after 8 days. This indicates that the plant resistance of these cultivars affected each biotype differently.Gonzalez Gonzalez, M. (2019). Caracterización de la resistencia de plantas de guisantes (pisum sativum) a dos biotipos de pulgón del guisante (Acyrthosiphon pisum). Universitat Politècnica de València. http://hdl.handle.net/10251/134060TFG