Highly Reduced Complementary Genomes of Dual Bacterial Symbionts in the Mulberry Psyllid Anomoneura mori.

The genomes of obligately host-restricted bacteria suffer from accumulating mildly deleterious mutations, resulting in marked size reductions. Psyllids (Hemiptera) are phloem sap-sucking insects with a specialized organ called the bacteriome, which typically harbors two vertically transmitted bacterial symbionts: the primary symbiont "Candidatus Carsonella ruddii" (Gammaproteobacteria) and a secondary symbiont that is phylogenetically diverse among psyllid lineages. The genomes of several Carsonella lineages were revealed to be markedly reduced (158-174‍ ‍kb), AT-rich (14.

A limited concentration range of diaphorin, a polyketide produced by a bacterial symbiont of the Asian citrus psyllid, promotes the gene expression with bacterial ribosomes.

Diaphorin is a polyketide produced by " Profftella armatura" (), an obligate symbiont of a devastating agricultural pest, the Asian citrus psyllid (Hemiptera: Psyllidae). Physiological concentrations of diaphorin, which contains at levels as high as 2-20 mM, are inhibitory to various eukaryotes and () but promote the growth and metabolic activity of (). Our previous study demonstrated that 5-mM diaphorin, which exhibits significant inhibitory and promoting effects on cultured and , respectively, inhibits gene expression utilizing purified and ribosomes.

Ultrastructure of the bacteriome and bacterial symbionts in the Asian citrus psyllid, .

Omics analyses suggested a mutually indispensable tripartite association among the host and organelle-like bacteriome associates, and , which are vertically transmitted through host generations. This relationship is based on the metabolic complementarity among these organisms, which is partly enabled by horizontal gene transfer between partners. However, little was known about the fine morphology of the symbionts and the bacteriome, the interface among these organisms.

Diaphorin, a polyketide produced by a bacterial endosymbiont of the Asian citrus psyllid, adversely affects the in vitro gene expression with ribosomes from Escherichia coli and Bacillus subtilis.

Diaphorin is a polyketide produced by "Candidatus Profftella armatura" (Gammaproteobacteria), an obligate mutualist of an important agricultural pest, the Asian citrus psyllid Diaphorina citri (Hemiptera). Our previous study demonstrated that diaphorin, at physiological concentrations in D. citri, inhibits the growth and cell division of Bacillus subtilis (Firmicutes) but promotes the growth and metabolic activity of Escherichia coli (Gammaproteobacteria).

16S rRNA Gene Sequencing of Six Psyllid Species of the Family Carsidaridae Identified Various Bacteria Including Symbiopectobacterium.

Psyllids (Hemiptera: Sternorrhyncha: Psylloidea) are plant sap-sucking insects that are closely associated with various microbes. To obtain a more detailed understanding of the ecological and evolutionary behaviors of microbes in Psylloidea, the bacterial populations of six psyllid species, belonging to the family Carsidaridae, were analyzed using high-throughput amplicon sequencing of the 16S rRNA gene. The majority of the secondary symbionts identified in the present study were gammaproteobacteria, particularly those of the order Enterobacterales, including Arsenophonus and Sodalis, which are lineages found in a wide variety of insect hosts.

High-resolution Microbiome Analyses of Nine Psyllid Species of the Family Triozidae Identified Previously Unrecognized but Major Bacterial Populations, including Liberibacter and Wolbachia of Supergroup O.

Psyllids (Hemiptera: Sternorrhyncha: Psylloidea) are plant sap-sucking insects that include important agricultural pests. To obtain insights into the ecological and evolutionary behaviors of microbes, including plant pathogens, in Psylloidea, high-resolution ana-lyses of the microbiomes of nine psyllid species belonging to the family Triozidae were performed using high-throughput amplicon sequencing of the 16S rRNA gene. Analyses identified various bacterial populations, showing that all nine psyllids have at least one secondary symbiont, along with the primary symbiont "Candidatus Carsonella ruddii" (Gammaproteobacteria: Oceanospirillales: Halomonadaceae).

Diaphorin, a Polyketide Produced by a Bacterial Symbiont of the Asian Citrus Psyllid, Inhibits the Growth and Cell Division of Bacillus subtilis but Promotes the Growth and Metabolic Activity of Escherichia coli.

Diaphorin is a polyketide produced by " Profftella armatura" (: ), an obligate symbiont of a notorious agricultural pest, the Asian citrus psyllid Diaphorina citri (Hemiptera: Psyllidae). Diaphorin belongs to the pederin family of bioactive agents found in various host-symbiont systems, including beetles, lichens, and sponges, harboring phylogenetically diverse bacterial producers. Previous studies showed that diaphorin, which is present in D.

Extreme Polyploidy of , an Organelle-Like Bacterium with a Drastically Reduced Genome.

Polyploidy is the state of having multiple copies of the genome within a nucleus or a cell, which has repeatedly evolved across the domains of life. Whereas most bacteria are monoploid, some bacterial species and endosymbiotic organelles that are derived from bacteria are stably polyploid. In the present study, using absolute quantitative PCR, we assessed the ploidy of Candidatus Carsonella ruddii (Gammaproteobacteria, Oceanospirillales), the obligate symbiont of the hackberry petiole gall psyllid, Pachypsylla venusta (Hemiptera, Psylloidea).

Microbiome analyses of 12 psyllid species of the family Psyllidae identified various bacteria including Fukatsuia and Serratia symbiotica, known as secondary symbionts of aphids.

Background: Psyllids (Hemiptera: Psylloidea) comprise a group of plant sap-sucking insects that includes important agricultural pests. They have close associations not only with plant pathogens, but also with various microbes, including obligate mutualists and facultative symbionts. Recent studies are revealing that interactions among such bacterial populations are important for psyllid biology and host plant pathology.

Comparative Genomics Underlines Multiple Roles of Profftella, an Obligate Symbiont of Psyllids: Providing Toxins, Vitamins, and Carotenoids.

The Asian citrus psyllid Diaphorina citri (Insecta: Hemiptera: Psylloidea), a serious pest of citrus species worldwide, harbors vertically transmitted intracellular mutualists, Candidatus Profftella armatura (Profftella_DC, Gammaproteobacteria: Burkholderiales) and Candidatus Carsonella ruddii (Carsonella_DC, Gammaproteobacteria: Oceanospirillales). Whereas Carsonella_DC is a typical nutritional symbiont, Profftella_DC is a unique defensive symbiont with organelle-like features, including intracellular localization within the host, perfect infection in host populations, vertical transmission over evolutionary time, and drastic genome reduction down to much less than 1 Mb. Large parts of the 460-kb genome of Profftella_DC are devoted to genes for synthesizing a polyketide toxin; diaphorin.

16S rRNA Sequencing Detected Profftella, Liberibacter, Wolbachia, and Diplorickettsia from Relatives of the Asian Citrus Psyllid.

The Asian citrus psyllid Diaphorina citri (Hemiptera: Psylloidea) is a serious pest of citrus species worldwide because it transmits Candidatus Liberibacter spp. (Alphaproteobacteria: Rhizobiales), the causative agents of the incurable citrus disease, huanglongbing or greening disease. Diaphorina citri possesses a specialized organ called a bacteriome, which harbors vertically transmitted intracellular mutualists, Ca.

Concentration and distribution of diaphorin, and expression of diaphorin synthesis genes during Asian citrus psyllid development.

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Psylloidea: Liviidae) is an important pest of citrus species worldwide because it transmits Candidatus Liberibacter spp. (Alphaproteobacteria); the causative agents of an incurable citrus disease known as huanglongbing or greening disease. D.

Diaphorin, a polyketide produced by a bacterial symbiont of the Asian citrus psyllid, kills various human cancer cells.

Diaphorin is a polyketide produced by Candidatus Profftella armatura (Betaproteobacteria), an organelle-like defensive symbiont harbored by a plant sap-sucking insect, Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae). Diaphorin belongs to the pederin family, a group of compounds that share much of their core structure with that of pederin, which is characterized by two dihydropyran rings bridged by an N-acyl aminal. Most members of this family have potent antitumor activity, making them promising anticancer drug candidates.

Diaphorin, a polyketide synthesized by an intracellular symbiont of the Asian citrus psyllid, is potentially harmful for biological control agents.

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Psylloidea: Liviidae) is an important pest of citrus species worldwide because it transmits Candidatus Liberibacter spp. (Alphaproteobacteria), the causative agents of an incurable citrus disease known as huanglongbing or greening disease. Diaphorina citri possesses a vertically-transmitted intracellular symbiont, Candidatus Profftella armatura (Betaproteobacteria), which produces diaphorin, a polyketide that is significantly toxic to mammalian cells.

Behavior of bacteriome symbionts during transovarial transmission and development of the Asian citrus psyllid.

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is a serious pest worldwide, transmitting Candidatus Liberibacter spp. (Alphaproteobacteria), the causative agents of a devastating citrus disease known as huanglongbing or greening disease. In a symbiotic organ called the bacteriome, D.

Horizontal gene transfers in insects.

Horizontal gene transfer is the transfer of genetic material across species boundaries. Although horizontal gene transfers are relatively rare in animals, the recent rapid accumulation of genomic data has identified increasing amounts of exogenous DNA inserts in insect genomes. Most of the horizontally acquired sequences appear to be non-functional; however, there is growing evidence that some genes are truly expressed and confer novel functions on the recipient insects.

[New insights from infection-specific gene expression network].

Most of our current knowledge about the gene regulation of pathogen comes from studies with in vitro conditions that mimic their host environments, revealing many types of virulence genes and their regulatory network. Recent advances in DNA sequencing and techniques for transcriptome analysis allow us to identify pathogenic genes specifically expressed in vivo. Analyses for gene expression of pathogens in response to the host environment, including immune response and change of bacterial flora during infection, provide clues to understanding the underlying events to establish the infectious diseases.

Parallel histories of horizontal gene transfer facilitated extreme reduction of endosymbiont genomes in sap-feeding insects.

Bacteria confined to intracellular environments experience extensive genome reduction. In extreme cases, insect endosymbionts have evolved genomes that are so gene-poor that they blur the distinction between bacteria and endosymbiotically derived organelles such as mitochondria and plastids. To understand the host's role in this extreme gene loss, we analyzed gene content and expression in the nuclear genome of the psyllid Pachypsylla venusta, a sap-feeding insect that harbors an ancient endosymbiont (Carsonella) with one of the most reduced bacterial genomes ever identified.

Horizontal gene acquisition of Liberibacter plant pathogens from a bacteriome-confined endosymbiont of their psyllid vector.

he Asian citrus psyllid Diaphorina citri is a notorious agricultural pest that transmits the phloem-inhabiting alphaproteobacterial 'Candidatus Liberibacter asiaticus' and allied plant pathogens, which cause the devastating citrus disease called Huanglongbing or greening disease. D. citri harbors two distinct bacterial mutualists in the symbiotic organ called bacteriome: the betaproteobacterium 'Candidatus Profftella armatura' in the syncytial cytoplasm at the center of the bacteriome, and the gammaproteobacterium 'Candidatus Carsonella ruddii' in uninucleate bacteriocytes.

Defensive bacteriome symbiont with a drastically reduced genome.

Diverse insect species harbor symbiotic bacteria, which play important roles such as provisioning nutrients and providing defense against natural enemies [1-6]. Whereas nutritional symbioses are often indispensable for both partners, defensive symbioses tend to be of a facultative nature [1-12]. The Asian citrus psyllid Diaphorina citri is a notorious agricultural pest that transmits Liberibacter spp.

Bacterial genes in the aphid genome: absence of functional gene transfer from Buchnera to its host.

Genome reduction is typical of obligate symbionts. In cellular organelles, this reduction partly reflects transfer of ancestral bacterial genes to the host genome, but little is known about gene transfer in other obligate symbioses. Aphids harbor anciently acquired obligate mutualists, Buchnera aphidicola (Gammaproteobacteria), which have highly reduced genomes (420-650 kb), raising the possibility of gene transfer from ancestral Buchnera to the aphid genome.

Immunity and other defenses in pea aphids, Acyrthosiphon pisum.

Background: Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements underlying responses to pathogens, parasites and stresses. At the center of pathogen-induced immune responses are signaling pathways triggered by the recognition of fungal, bacterial and viral signatures. These pathways result in the production of response molecules, such as antimicrobial peptides and lysozymes, which degrade or destroy invaders.

Aphids acquired symbiotic genes via lateral gene transfer.

Background: Aphids possess bacteriocytes, which are cells specifically differentiated to harbour the obligate mutualist Buchnera aphidicola (gamma-Proteobacteria). Buchnera has lost many of the genes that appear to be essential for bacterial life. From the bacteriocyte of the pea aphid Acyrthosiphon pisum, we previously identified two clusters of expressed sequence tags that display similarity only to bacterial genes.

Genomics and evolution of heritable bacterial symbionts.

Insect heritable symbionts have proven to be ubiquitous, based on molecular screening of various insect lineages. Recently, molecular and experimental approaches have yielded an immensely richer understanding of their diverse biological roles, resulting in a burgeoning research literature. Increasingly, commonalities and intermediates are being discovered between categories of symbionts once considered distinct: obligate mutualists that provision nutrients, facultative mutualists that provide protection against enemies or stress, and symbionts such as Wolbachia that manipulate reproductive systems.