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Amparo Latorre - One of the best experts on this subject based on the ideXlab platform.
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New Clues about the Evolutionary History of Metabolic Losses in Bacterial Endosymbionts, Provided by the Genome of Buchnera aphidicola from the Aphid Cinara tujafilina
Applied and environmental microbiology, 2011Co-Authors: Araceli Lamelas, Andres Moya, María José Gosalbes, Amparo LatorreAbstract:The symbiotic association between aphids (Homoptera) and Buchnera aphidicola (Gammaproteobacteria) started about 100 to 200 million years ago. As a consequence of this relationship, the bacterial genome has undergone a prominent size reduction. The downsize genome process starts when the bacterium enters the host and will probably end with its extinction and replacement by another healthier bacterium or with the establishment of metabolic complementation between two or more bacteria. Nowadays, several complete genomes of Buchnera aphidicola from four different aphid species (Acyrthosiphon pisum, Schizaphis graminum, Baizongia pistacea, and Cinara cedri) have been fully sequenced. C. cedri belongs to the subfamily Lachninae and harbors two coprimary bacteria that fulfill the metabolic needs of the whole consortium: B. aphidicola with the smallest genome reported so far and “Candidatus Serratia symbiotica.” In addition, Cinara tujafilina, another member of the subfamily Lachninae, closely related to C. cedri, also harbors “Ca. Serratia symbiotica” but with a different phylogenetic status than the one from C. cedri. In this study, we present the complete genome sequence of B. aphidicola from C. tujafilina and the phylogenetic analysis and comparative genomics with the other Buchnera genomes. Furthermore, the gene repertoire of the last common ancestor has been inferred, and the evolutionary history of the metabolic losses that occurred in the different lineages has been analyzed. Although stochastic gene loss plays a role in the genome reduction process, it is also clear that metabolism, as a functional constraint, is also a powerful evolutionary force in insect endosymbionts.
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New Insights on the Evolutionary History of Aphids and Their Primary Endosymbiont Buchnera aphidicola
International journal of evolutionary biology, 2011Co-Authors: Vicente Pérez-brocal, Andres Moya, Rosario Gil, Amparo LatorreAbstract:Since the establishment of the symbiosis between the ancestor of modern aphids and their primary endosymbiont, Buchnera aphidicola, insects and bacteria have coevolved. Due to this parallel evolution, the analysis of bacterial genomic features constitutes a useful tool to understand their evolutionary history. Here we report, based on data from B. aphidicola, the molecular evolutionary analysis, the phylogenetic relationships among lineages and a comparison of sequence evolutionary rates of symbionts of four aphid species from three subfamilies. Our results support previous hypotheses of divergence of B. aphidicola and their host lineages during the early Cretaceous and indicate a closer relationship between subfamilies Eriosomatinae and Lachninae than with the Aphidinae. They also reveal a general evolutionary pattern among strains at the functional level. We also point out the effect of lifecycle and generation time as a possible explanation for the accelerated rate in B. aphidicola from the Lachninae.
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Genome reduction of the aphid endosymbiont Buchnera aphidicola in a recent evolutionary time scale.
Gene, 2006Co-Authors: Laura Gomez-valero, Francisco J. Silva, J.c. Simon, Amparo LatorreAbstract:Genome reduction, a typical feature of symbiotic bacteria, was analyzed in the last stages of evolution of Buchnera aphidicola, the primary aphid endosymbiont, in two neutrally evolving regions: the pseudogene cmk and an intergenic region. These two regions were examined in endosymbionts from several lineages of their aphid host Rhopalosiphum padi, and different species of the same genus, whose divergence times ranged from 0.62 to 19.51 million years. Estimates of nucleotide substitution rates were between 4.3 and 6.7×10 �9 substitution/site/year, with G or C nucleotides being substituted around four times more frequently than A or T. Two different types of indel events were detected, of which many were small (1–10 nt) but one was large (about 200 nucleotides).With respect to the large one and considering the proportion and size of the deletions and insertions, the reduction rate was 1.3×10 �8 lost nucleotides/site/year. We propose a stepwise scenario for the last stages of evolution
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a small microbial genome the end of a long symbiotic relationship
Science, 2006Co-Authors: Vicente Perezbrocal, Andres Moya, Francisco J. Silva, Marina Postigo, Araceli Lamelas, Silvia Ramos, Jose Manuel Michelena, Amparo LatorreAbstract:Intracellular bacteria are characterized by genome reduction. The 422,434–base pair genome of Buchnera aphidicola BCc, primary endosymbiont of the aphid Cinara cedri, is ∼200 kilobases smaller than the previously sequenced B. aphidicola genomes. B. aphidicola BCc has lost most metabolic functions, including the ability to synthesize the essential amino acid tryptophan and riboflavin. In addition, most retained genes are evolving rapidly. Possibly, B. aphidicola BCc is losing its symbiotic capacity and is being complemented (and might be replaced) by the highly abundant coexisting secondary symbiont.
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A small microbial genome: the end of a long symbiotic relationship?
Science (New York N.Y.), 2006Co-Authors: Vicente Pérez-brocal, Andres Moya, Francisco J. Silva, Rosario Gil, Marina Postigo, Araceli Lamelas, Silvia Ramos, Jose Manuel Michelena, Amparo LatorreAbstract:Intracellular bacteria are characterized by genome reduction. The 422,434-base pair genome of Buchnera aphidicola BCc, primary endosymbiont of the aphid Cinara cedri, is approximately 200 kilobases smaller than the previously sequenced B. aphidicola genomes. B. aphidicola BCc has lost most metabolic functions, including the ability to synthesize the essential amino acid tryptophan and riboflavin. In addition, most retained genes are evolving rapidly. Possibly, B. aphidicola BCc is losing its symbiotic capacity and is being complemented (and might be replaced) by the highly abundant coexisting secondary symbiont.
Paul Baumann - One of the best experts on this subject based on the ideXlab platform.
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Detection of Messenger RNA Transcribed from Genes Encoding Enzymes of Amino Acid Biosynthesis in Buchnera aphidicola (Endosymbiont of Aphids)
Current microbiology, 1999Co-Authors: Linda Baumann, Paul Baumann, Mylo Ly ThaoAbstract:The aphid Schizaphis graminum is dependent on Buchnera aphidicola, a prokaryotic endosymbiont. One of the functions of the endosymbiont is the synthesis of essential amino acids for the aphid host. Previously we have found that B. aphidicola has many of the genes that encode enzymes of amino acid biosynthesis. Using reverse transcriptase and the polymerase chain reaction, we have detected messenger RNA corresponding to genes involved in the synthesis of tryptophan, isoleucine, valine, leucine, and histidine.
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Buchnera aphidicola(Aphid Endosymbiont) Contains Genes Encoding Enzymes of Histidine Biosynthesis
Current microbiology, 1998Co-Authors: Marta A Clark, Linda Baumann, Paul BaumannAbstract:Buchnera aphidicola is an endosymbiont of aphids. One of its functions appears to be the synthesis of essential amino acids for the aphid host. A 12.8-kilobase B. aphidicola DNA fragment has been cloned and sequenced. It contains genes encoding all of the enzymes required for the biosynthesis of the essential amino acid histidine. The order of the genes, hisGDCBHAFI, is the same as that found in Escherichia coli and is consistent with their constituting a single transcription unit. The DNA fragment also contained genes involved in aromatic amino acid biosynthesis (aroC), the oxidative pentose pathway ( gnd), and 28-deoxyribonucleotide metabolism (dcd), as well as a tRNA synthase (metG). Buchnera aphidicola is a prokaryotic, non-culturable symbiont found in specialized cells (bacteriocytes) within the body cavity of the aphid, Schizaphis graminum. Aphids, like other insects, require ten preformed amino acids, and there is evidence that one of the functions of the endosymbiont is the synthesis of these amino acids for the aphid host (for reviews see (3, 9, 10)). Nucleotide (nt) sequence analysis of the endosymbiont genome can reveal its metabolic potential. A partial sequence of the B. aphidicola genome has indicated that it has genes for a variety of core functions including DNA synthesis, transcription, translation, energy-yielding metabolism, cell wall synthesis, and cell division (4, 5). Unlike the parasites Mycoplasma genitalium(11) and Borrelia burg- dorferi (12), which lack genes for enzymes involved in amino acid biosynthesis, B. aphidicola has genes coding for enzymes involved in the biosynthesis of the essential amino acids tryptophan, isoleucine, valine, leucine, and lysine (4, 5, 8, 14). These findings are consistent with the potential of B. aphidicola to overproduce these amino acids for the aphid host. In the case of tryptophan and leucine biosyntheses, the endosymbiont has genetic modi- fications resulting in amplification of genes coding for a limiting regulated enzyme (4, 5) or an increase in the number of copies of genes coding for enzymes of a
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Sequence analysis of a DNA fragment from Buchnera aphidicola (Aphid Endosymbiont) containing the genes dapD-htrA-ilvI-ilvH-ftsL-ftsI-murE
Current microbiology, 1998Co-Authors: Mylo Ly Thao, Paul BaumannAbstract:Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. One of the endosymbiont's functions is the synthesis of branched-chain amino acids. A 9.7-kilobase B. aphidicola chromosomal DNA fragment was cloned and sequenced and found to contain genes encoding acetohydroxy acid synthase (ilvIH), the first enzyme of the parallel pathway of isoleucine and valine biosynthesis. Previously we have detected ilvC and ilvD, encoding the two other enzymes of this pathway. In addition the DNA fragment contained genes for cell division (ftsL, ftsI), murein biosynthesis (murE), lysine biosynthesis (dapD) and a periplasmic protease (htrA). In these properties B. aphidicola resembles free-living bacteria.
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Characterization of ftsZ, the cell division gene of Buchnera aphidicola (endosymbiont of aphids) and detection of the product.
Current microbiology, 1998Co-Authors: Linda Baumann, Paul BaumannAbstract:Buchnera aphidicola, the endosymbiont of the aphid Schizaphis graminum, contains the gene ftsZ, which codes for a protein involved in the initiation of septum formation during cell division. With immunological techniques, this protein has been detected in cell-free extracts of the endosymbiont. Nucleotide sequence determination of a 6.4-kilobase B. aphidicola DNA fragment has indicated that, as in E. coli, ftsZ is adjacent to genes coding for other cell division proteins as well as genes involved in murein synthesis (murC–ddlB–ftsA–ftsZ). Although B. aphidicola ftsZ is expressed in E. coli, it cannot complement E. coli ftsZ mutants. High levels of B. aphidicola FtsZ results in the formation of long filamentous E. coli cells, suggesting that this protein interferes with cell division. The presence of FtsZ indicates that in this, as well as in many other previously described properties, B. aphidicola resembles free-living bacteria.
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Sequence Analysis of a 34.7-kb DNA Segment from the Genome of Buchnera aphidicola (Endosymbiont of Aphids) Containing groEL, dnaA, the atp operon, gidA, and rho
Current microbiology, 1998Co-Authors: Marta A Clark, Linda Baumann, Paul BaumannAbstract:Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. From past and present nucleotide sequence analyses of the B. aphidicola genome, we have assembled a 34.7-kilobase (kb) DNA segment. This segment contains genes coding for 32 open reading frames (ORFs), which corresponded to 89.9% of the DNA. All of these ORFs could be identified with homologous regions of the Escherichia coli genome. The order of the genes with established functions was groELS–trmE–rnpA–rpmH–dnaA–dnaN–gyrB–atpCDGAHFEB–gidA–fdx–hscA– hscB–nifS–ilvDC–rep–trxA–rho. The order of genes in small DNA fragments was conserved in both B. aphidicola and E. coli. Most of these fragments were in approximately the same region of the E. coli genome. The latter organism, however, contained many additional inserted genes within and between the fragments. The results of the B. aphidicola genome analyses indicate that the endosymbiont has many properties of free-living bacteria.
Nancy A. Moran - One of the best experts on this subject based on the ideXlab platform.
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isolation of the Buchnera aphidicola flagellum basal body complexes from the Buchnera membrane
PLOS ONE, 2021Co-Authors: Matthew J. Schepers, Nancy A. Moran, James N. Yelland, David W. TaylorAbstract:Buchnera aphidicola is an intracellular bacterial symbiont of aphids and maintains a small genome of only 600 kbps. Buchnera is thought to maintain only genes relevant to the symbiosis with its aphid host. Curiously, the Buchnera genome contains gene clusters coding for flagellum basal body structural proteins and for flagellum type III export machinery. These structures have been shown to be highly expressed and present in large numbers on Buchnera cells. No recognizable pathogenicity factors or secreted proteins have been identified in the Buchnera genome, and the relevance of this protein complex to the symbiosis is unknown. Here, we show isolation of Buchnera flagellum basal body proteins from the cellular membrane of Buchnera, confirming the enrichment of flagellum basal body proteins relative to other proteins in the Buchnera proteome. This will facilitate studies of the structure and function of the Buchnera flagellum structure, and its role in this model symbiosis.
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Isolation of the Buchnera aphidicola flagellum basal body from the Buchnera membrane
2021Co-Authors: Matthew J. Schepers, Nancy A. Moran, James N. Yelland, David W. TaylorAbstract:Abstract Buchnera aphidicola is an intracellular bacterial symbiont of aphids and maintains a small genome of only 600 kbps. Buchnera is thought to maintain only genes relevant to the symbiosis with its aphid host. Curiously, the Buchnera genome contains gene clusters coding for flagellum basal body structural proteins and for flagellum type III export machinery. These structures have been shown to be highly expressed and present in large numbers on Buchnera cells. No recognizable pathogenicity factors or secreted proteins have been identified in the Buchnera genome, and the relevance of this protein complex to the symbiosis is unknown. Here, we show isolation of Buchnera flagella from the cellular membrane of Buchnera, confirming the enrichment of flagellum proteins relative to other proteins in the Buchnera proteome. This will facilitate studies of the structure and function of the Buchnera flagellum structure, and its role in this model symbiosis.
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genome evolution of the obligate endosymbiont Buchnera aphidicola
Molecular Biology and Evolution, 2019Co-Authors: Hyunjin Park, Rebecca A Chong, Nancy A. MoranAbstract:An evolutionary consequence of uniparentally transmitted symbiosis is degradation of symbiont genomes. We use the system of aphids and their maternally inherited obligate endosymbiont, Buchnera aphidicola, to explore the evolutionary process of genome degradation. We compared complete genome sequences for 39 Buchnera strains, including 23 newly sequenced symbiont genomes from diverse aphid hosts. We reconstructed the genome of the most recent shared Buchnera ancestor, which contained 616 protein-coding genes, and 39 RNA genes. The extent of subsequent gene loss varied across lineages, resulting in modern genomes ranging from 412 to 646 kb and containing 354-587 protein-coding genes. Loss events were highly nonrandom across loci. Genes involved in replication, transcription, translation, and amino acid biosynthesis are largely retained, whereas genes underlying ornithine biosynthesis, stress responses, and transcriptional regulation were lost repeatedly. Aside from losses, gene order is almost completely stable. The main exceptions involve movement between plasmid and chromosome locations of genes underlying tryptophan and leucine biosynthesis and supporting nutrition of aphid hosts. This set of complete genomes enabled tests for signatures of positive diversifying selection. Of 371 Buchnera genes tested, 29 genes show strong support for ongoing positive selection. These include genes encoding outer membrane porins that are expected to be involved in direct interactions with hosts. Collectively, these results indicate that extensive genome reduction occurred in the ancestral Buchnera prior to aphid diversification and that reduction has continued since, with losses greater in some lineages and for some loci.
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a dual genome microarray for the pea aphid acyrthosiphon pisum and its obligate bacterial symbiont Buchnera aphidicola
BMC Genomics, 2006Co-Authors: Alex C C Wilson, Helen E. Dunbar, Gregory K Davis, Wayne B Hunter, David L Stern, Nancy A. MoranAbstract:The best studied insect-symbiont system is that of aphids and their primary bacterial endosymbiont Buchnera aphidicola. Buchnera inhabits specialized host cells called bacteriocytes, provides nutrients to the aphid and has co-speciated with its aphid hosts for the past 150 million years. We have used a single microarray to examine gene expression in the pea aphid, Acyrthosiphon pisum, and its resident Buchnera. Very little is known of gene expression in aphids, few studies have examined gene expression in Buchnera, and no study has examined simultaneously the expression profiles of a host and its symbiont. Expression profiling of aphids, in studies such as this, will be critical for assigning newly discovered A. pisum genes to functional roles. In particular, because aphids possess many genes that are absent from Drosophila and other holometabolous insect taxa, aphid genome annotation efforts cannot rely entirely on homology to the best-studied insect systems. Development of this dual-genome array represents a first attempt to characterize gene expression in this emerging model system. We chose to examine heat shock response because it has been well characterized both in Buchnera and in other insect species. Our results from the Buchnera of A. pisum show responses for the same gene set as an earlier study of heat shock response in Buchnera for the host aphid Schizaphis graminum. Additionally, analyses of aphid transcripts showed the expected response for homologs of known heat shock genes as well as responses for several genes with unknown functional roles. We examined gene expression under heat shock of an insect and its bacterial symbiont in a single assay using a dual-genome microarray. Further, our results indicate that microarrays are a useful tool for inferring functional roles of genes in A. pisum and other insects and suggest that the pea aphid genome may contain many gene paralogs that are differentially regulated.
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Low and homogeneous copy number of plasmid-borne symbiont genes affecting host nutrition in Buchnera aphidicola of the aphid Uroleucon ambrosiae.
Molecular ecology, 2003Co-Authors: Gordon R. Plague, Colin Dale, Nancy A. MoranAbstract:The bacterial endosymbiont of aphids, Buchnera aphidicola, often provides amino acids to its hosts. Plasmid amplification of leucine (leuABCD) and tryptophan (trpEG) biosynthesis genes may be a mechanism by which some Buchnera over-produce these nutrients. We used quantitative polymerase chain reaction to assess the leuABCD/trpEG copy variability within Uroleucon ambrosiae, an aphid with a wide diet breadth and range. Both leuABCD and trpEG abundances are: (i) similar for aphids across 15 populations, and (ii) low compared to Buchnera from other aphid species (particularly trpEG). Consequently, the plasmid location of trpEG combined with Buchnera's chromosomal polyploidy may functionally limit, rather than increase, tryptophan production within Uroleucon ambrosiae.
Francisco J. Silva - One of the best experts on this subject based on the ideXlab platform.
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Genome reduction of the aphid endosymbiont Buchnera aphidicola in a recent evolutionary time scale
Gene, 2007Co-Authors: Laura Gomez-valero, Francisco J. Silva, J.c. Simon, Amandine LatorreAbstract:Genome reduction, a typical feature of symbiotic bacteria, was analyzed in the last stages of evolution of Buchnera aphidicola, the primary aphid endosymbiont, in two neutrally evolving regions: the pseudogene cmk and an intergenic region. These two regions were examined in endosymbionts from several lineages of their aphid host Rhopalosiphum padi, and different species of the same genus, whose divergence times ranged from 0.62 to 19.51 million years. Estimates of nucleotide substitution rates were between 4.3 and 6.7 x 10(-9) substitution/site/year, with G or C nucleotides being substituted around four times more frequently than A or T. Two different types of indel events were detected, of which many were small (1-10 nt) but one was large (about 200 nucleotides). With respect to the large one and considering the proportion and size of the deletions and insertions, the reduction rate was 1.3 x 10(-8) lost nucleotides/site/year. We propose a stepwise scenario for the last stages of evolution in B. aphidicola: together with a very slow and gradual degradation, considerable indels would punctually emerge. The only restriction to large deletion fixation is that the lost fragment does not contain essential genes.
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Genome reduction of the aphid endosymbiont Buchnera aphidicola in a recent evolutionary time scale.
Gene, 2006Co-Authors: Laura Gomez-valero, Francisco J. Silva, J.c. Simon, Amparo LatorreAbstract:Genome reduction, a typical feature of symbiotic bacteria, was analyzed in the last stages of evolution of Buchnera aphidicola, the primary aphid endosymbiont, in two neutrally evolving regions: the pseudogene cmk and an intergenic region. These two regions were examined in endosymbionts from several lineages of their aphid host Rhopalosiphum padi, and different species of the same genus, whose divergence times ranged from 0.62 to 19.51 million years. Estimates of nucleotide substitution rates were between 4.3 and 6.7×10 �9 substitution/site/year, with G or C nucleotides being substituted around four times more frequently than A or T. Two different types of indel events were detected, of which many were small (1–10 nt) but one was large (about 200 nucleotides).With respect to the large one and considering the proportion and size of the deletions and insertions, the reduction rate was 1.3×10 �8 lost nucleotides/site/year. We propose a stepwise scenario for the last stages of evolution
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a small microbial genome the end of a long symbiotic relationship
Science, 2006Co-Authors: Vicente Perezbrocal, Andres Moya, Francisco J. Silva, Marina Postigo, Araceli Lamelas, Silvia Ramos, Jose Manuel Michelena, Amparo LatorreAbstract:Intracellular bacteria are characterized by genome reduction. The 422,434–base pair genome of Buchnera aphidicola BCc, primary endosymbiont of the aphid Cinara cedri, is ∼200 kilobases smaller than the previously sequenced B. aphidicola genomes. B. aphidicola BCc has lost most metabolic functions, including the ability to synthesize the essential amino acid tryptophan and riboflavin. In addition, most retained genes are evolving rapidly. Possibly, B. aphidicola BCc is losing its symbiotic capacity and is being complemented (and might be replaced) by the highly abundant coexisting secondary symbiont.
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A small microbial genome: the end of a long symbiotic relationship?
Science (New York N.Y.), 2006Co-Authors: Vicente Pérez-brocal, Andres Moya, Francisco J. Silva, Rosario Gil, Marina Postigo, Araceli Lamelas, Silvia Ramos, Jose Manuel Michelena, Amparo LatorreAbstract:Intracellular bacteria are characterized by genome reduction. The 422,434-base pair genome of Buchnera aphidicola BCc, primary endosymbiont of the aphid Cinara cedri, is approximately 200 kilobases smaller than the previously sequenced B. aphidicola genomes. B. aphidicola BCc has lost most metabolic functions, including the ability to synthesize the essential amino acid tryptophan and riboflavin. In addition, most retained genes are evolving rapidly. Possibly, B. aphidicola BCc is losing its symbiotic capacity and is being complemented (and might be replaced) by the highly abundant coexisting secondary symbiont.
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Plasmids in the aphid endosymbiont Buchnera aphidicola with the smallest genomes. A puzzling evolutionary story.
Gene, 2006Co-Authors: Rosario Gil, Francisco J. Silva, Vicente Pérez-brocal, Beatriz Sabater-muñoz, Amparo LatorreAbstract:Buchnera aphidicola, the primary endosymbiont of aphids, has undergone important genomic and biochemical changes as an adaptation to intracellular life. The most important structural changes include a drastic genome reduction and the amplification of genes encoding key enzymes for the biosynthesis of amino acids by their translocation to plasmids. Molecular characterization through different aphid subfamilies has revealed that the genes involved in leucine and tryptophan biosynthesis show a variable fate, since they can be located on plasmids or on the chromosome in different lineages. This versatility contrasts with the genomic stasis found in three distantly related B. aphidicola strains already sequenced. We present the analysis of three B. aphidicola strains (BTg, BCt and BCc) belonging to aphids from different tribes of the subfamily Lachninae, that was estimated to harbour the bacteria with the smallest genomes. The presence of both leucine and tryptophan plasmids in BTg, a chimerical leucine-tryptophan plasmid in BCt, and only a leucine plasmid in BCc, indicates the existence of many recombination events in a recA minus bacterium. In addition, these B. aphidicola plasmids are the simplest described in this species, indicating that plasmids are also involved in the genome shrinkage process.
Alex C C Wilson - One of the best experts on this subject based on the ideXlab platform.
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ontogenetic differences in localization of glutamine transporter apglnt1 in the pea aphid demonstrate that mechanisms of host symbiont integration are not similar in the maternal versus embryonic bacteriome
Evodevo, 2016Co-Authors: Daniel R G Price, Athula H Wikramanayake, Chunche Chang, Alex C C WilsonAbstract:Background Obligate intracellular symbionts of insects are metabolically and developmentally integrated with their hosts. Typically, reproduction fails in many insect nutritional endosymbioses when host insects are cured of their bacterial symbionts, and yet remarkably little is known about the processes that developmentally integrate host and symbiont. Here in the best studied insect obligate intracellular symbiosis, that of the pea aphid, Acyrthosiphon pisum, with the gammaproteobacterium Buchnera aphidicola, we tracked the expression and localization of amino acid transporter ApGLNT1 gene products during asexual embryogenesis. Recently being characterized as a glutamine transporter, ApGLNT1 has been proposed to be a key regulator of amino acid biosynthesis in A. pisum bacteriocytes. To determine when this important mediator of the symbiosis becomes expressed in aphid embryonic bacteriocytes, we applied whole-mount in situ hybridization and fluorescent immunostaining with a specific anti-ApGLNT1 antibody to detect the temporal and spatial expression of ApGLNT1 gene products during asexual embryogenesis.
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Comparative analysis of genome sequences from four strains of the Buchnera aphidicola Mp endosymbion of the green peach aphid, Myzus persicae
BMC genomics, 2013Co-Authors: Zhijie Jiang, Georg Jander, Derek H. Jones, Sawsan Khuri, Nicholas F. Tsinoremas, Tania Wyss, Alex C C WilsonAbstract:Background Myzus persicae, the green peach aphid, is a polyphagous herbivore that feeds from hundreds of species of mostly dicot crop plants. Like other phloem-feeding aphids, M. persicae rely on the endosymbiotic bacterium, Buchnera aphidicola (Buchnera Mp), for biosynthesis of essential amino acids and other nutrients that are not sufficiently abundant in their phloem sap diet. Tobacco-specialized M. persicae are typically red and somewhat distinct from other lineages of this species. To determine whether the endosymbiotic bacteria of M. persicae could play a role in tobacco adaptation, we sequenced the Buchnera Mp genomes from two tobacco-adapted and two non-tobacco M. persicae lineages.
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genomic revelations of a mutualism the pea aphid and its obligate bacterial symbiont
Cellular and Molecular Life Sciences, 2011Co-Authors: Shuji Shigenobu, Alex C C WilsonAbstract:The symbiosis of the pea aphid Acyrthosphion pisum with the bacterium Buchnera aphidicola APS represents the best-studied insect obligate symbiosis. Here we present a refined picture of this symbiosis by linking pre-genomic observations to new genomic data that includes the complete genomes of the eukaryotic and prokaryotic symbiotic partners. In doing so, we address four issues central to understanding the patterns and processes operating at the A. pisum/Buchnera APS interface. These four issues include: (1) lateral gene transfer, (2) host immunity, (3) symbiotic metabolism, and (4) regulation.
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genomic insight into the amino acid relations of the pea aphid acyrthosiphon pisum with its symbiotic bacterium Buchnera aphidicola
Insect Molecular Biology, 2010Co-Authors: Alex C C Wilson, Federica Calevro, Hubert Charles, Stefano Colella, P F Kushlan, Sandy J Macdonald, Peter D Ashton, Gerard Febvay, Georg Jander, J. F. SchwartzAbstract:The pea aphid genome includes 66 genes contributing to amino acid biosynthesis and 93 genes to amino acid degradation. In several respects, the pea aphid gene inventory complements that of its symbiotic bacterium, Buchnera aphidicola (Buchnera APS). Unlike other insects with completely sequenced genomes, the pea aphid lacks the capacity to synthesize arginine, which is produced by Buchnera APS. However, consistent with other insects, it has genes coding for individual reactions in essential amino acid biosynthesis, including threonine dehydratase and branched-chain amino acid aminotransferase, which are not coded in the Buchnera APS genome. Overall the genome data suggest that the biosynthesis of certain essential amino acids is shared between the pea aphid and Buchnera APS, providing the opportunity for precise aphid control over Buchnera metabolism.
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a dual genome microarray for the pea aphid acyrthosiphon pisum and its obligate bacterial symbiont Buchnera aphidicola
BMC Genomics, 2006Co-Authors: Alex C C Wilson, Helen E. Dunbar, Gregory K Davis, Wayne B Hunter, David L Stern, Nancy A. MoranAbstract:The best studied insect-symbiont system is that of aphids and their primary bacterial endosymbiont Buchnera aphidicola. Buchnera inhabits specialized host cells called bacteriocytes, provides nutrients to the aphid and has co-speciated with its aphid hosts for the past 150 million years. We have used a single microarray to examine gene expression in the pea aphid, Acyrthosiphon pisum, and its resident Buchnera. Very little is known of gene expression in aphids, few studies have examined gene expression in Buchnera, and no study has examined simultaneously the expression profiles of a host and its symbiont. Expression profiling of aphids, in studies such as this, will be critical for assigning newly discovered A. pisum genes to functional roles. In particular, because aphids possess many genes that are absent from Drosophila and other holometabolous insect taxa, aphid genome annotation efforts cannot rely entirely on homology to the best-studied insect systems. Development of this dual-genome array represents a first attempt to characterize gene expression in this emerging model system. We chose to examine heat shock response because it has been well characterized both in Buchnera and in other insect species. Our results from the Buchnera of A. pisum show responses for the same gene set as an earlier study of heat shock response in Buchnera for the host aphid Schizaphis graminum. Additionally, analyses of aphid transcripts showed the expected response for homologs of known heat shock genes as well as responses for several genes with unknown functional roles. We examined gene expression under heat shock of an insect and its bacterial symbiont in a single assay using a dual-genome microarray. Further, our results indicate that microarrays are a useful tool for inferring functional roles of genes in A. pisum and other insects and suggest that the pea aphid genome may contain many gene paralogs that are differentially regulated.
