| evolutionary relationships of three new species of enterobacteriaceae living as symbionts of aphids and other insects. | ecological studies on three bacterial lineages symbiotic in aphids have shown that they impose a variety of effects on their hosts, including resistance to parasitoids and tolerance to heat stress. phylogenetic analyses of partial sequences of gyrb and reca are consistent with previous analyses limited to 16s rrna gene sequences and yield improved confidence of the evolutionary relationships of these symbionts. all three symbionts are in the enterobacteriaceae. one of the symbionts, here given t ... | 2005 | 15933033 |
| population dynamics of defensive symbionts in aphids. | vertically transmitted micro-organisms can increase in frequency in host populations by providing net benefits to hosts. while laboratory studies have identified diverse beneficial effects conferred by inherited symbionts of insects, they have not explicitly examined the population dynamics of mutualist symbiont infection within populations. in the pea aphid, acyrthosiphon pisum, the inherited facultative symbiont, hamiltonella defensa, provides protection against parasitism by the wasp, aphidiu ... | 2008 | 18029301 |
| the striking case of tryptophan provision in the cedar aphid cinara cedri. | buchnera aphidicola bcc has lost its symbiotic role as the tryptophan supplier to the aphid cinara cedri. we report the presence of a plasmid in this endosymbiont that contains the trpeg genes. the remaining genes for the pathway (trpdcba) are located on the chromosome of the secondary endosymbiont "candidatus serratia symbiotica." thus, we propose that a symbiotic consortium is necessary to provide tryptophan. | 2008 | 18586942 |
| the genome of buchnera aphidicola from the aphid cinara tujafilina provides new clues about the evolutionary history of metabolic losses in bacterial endosymbionts. | the symbiotic association between aphids (homoptera) and buchnera aphidicola (γ-proteobacteria) started about 100-200 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, sever ... | 2011 | 21571878 |
| comparative genomics of serratia spp.: two paths towards endosymbiotic life. | symbiosis is a widespread phenomenon in nature, in which insects show a great number of these associations. buchnera aphidicola, the obligate endosymbiont of aphids, coexists in some species with another intracellular bacterium, serratia symbiotica. of particular interest is the case of the cedar aphid cinara cedri, where b. aphidicola bcc and s. symbiotica scc need each other to fulfil their symbiotic role with the insect. moreover, various features seem to indicate that s. symbiotica scc is cl ... | 2012 | 23077583 |
| infection dynamic of symbiotic bacteria in the pea aphid acyrthosiphon pisum gut and host immune response at the early steps in the infection process. | in addition to its obligatory symbiont buchnera aphidicola, the pea aphid acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. belonging to a genus where many members have been described as pathogen in invertebrates, serratia symbiotica is one of the most common facultative partners found in aphids. the recent discovery of strains able to grow outside their host allowed us to simulate environmental acqu ... | 2015 | 25811863 |
| snapshots of a shrinking partner: genome reduction in serratia symbiotica. | genome reduction is pervasive among maternally-inherited endosymbiotic organisms, from bacteriocyte- to gut-associated ones. this genome erosion is a step-wise process in which once free-living organisms evolve to become obligate associates, thereby losing non-essential or redundant genes/functions. serratia symbiotica (gammaproteobacteria), a secondary endosymbiont present in many aphids (hemiptera: aphididae), displays various characteristics that make it a good model organism for studying gen ... | 2016 | 27599759 |
| 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 |
| aphid facultative symbionts reduce survival of the predatory lady beetle hippodamia convergens. | non-essential facultative endosymbionts can provide their hosts with protection from parasites, pathogens, and predators. for example, two facultative bacterial symbionts of the pea aphid (acyrthosiphon pisum), serratia symbiotica and hamiltonella defensa, protect their hosts from parasitism by two species of parasitoid wasp. previous studies have not explored whether facultative symbionts also play a defensive role against predation in this system. we tested whether feeding on aphids harboring ... | 2014 | 24555501 |
| settling down: the genome of serratia symbiotica from the aphid cinara tujafilina zooms in on the process of accommodation to a cooperative intracellular life. | particularly interesting cases of mutualistic endosymbioses come from the establishment of co-obligate associations of more than one species of endosymbiotic bacteria. throughout symbiotic accommodation from a free-living bacterium, passing through a facultative stage and ending as an obligate intracellular one, the symbiont experiences massive genomic losses and phenotypic adjustments. here, we scrutinized the changes in the coevolution of serratia symbiotica and buchnera aphidicola endosymbion ... | 2014 | 24951564 |
| the cellular immune response of the pea aphid to foreign intrusion and symbiotic challenge. | recent studies suggest that the pea aphid (acyrthosiphon pisum) has low immune defenses. however, its immune components are largely undescribed, and notably, extensive characterization of circulating cells has been missing. here, we report characterization of five cell categories in hemolymph of adults of the ll01 pea aphid clone, devoid of secondary symbionts (ss): prohemocytes, plasmatocytes, granulocytes, spherulocytes and wax cells. circulating lipid-filed wax cells are rare; they otherwise ... | 2012 | 22848726 |
| bacteria associated with gut lumen of camponotus japonicus mayr. | camponotus ants harbor the obligate intracellular endosymbiont blochmannia in their midgut bacteriocytes, but little is known about intestinal bacteria living in the gut lumen. in this paper we reported the results of a survey of the intestinal microflora of camponotus japonicus mayr based on small-subunit rrna genes (16s rrnas) polymerase chain reaction (pcr)-restriction fragment-length polymorphism analysis of worker guts. from 107 clones, 11 different restriction fragment-length polymorphism ... | 2011 | 22217755 |
| Serratia symbiotica from the aphid Cinara cedri: a missing link from facultative to obligate insect endosymbiont. | The genome sequencing of Buchnera aphidicola BCc from the aphid Cinara cedri, which is the smallest known Buchnera genome, revealed that this bacterium had lost its symbiotic role, as it was not able to synthesize tryptophan and riboflavin. Moreover, the biosynthesis of tryptophan is shared with the endosymbiont Serratia symbiotica SCc, which coexists with B. aphidicola in this aphid. The whole-genome sequencing of S. symbiotica SCc reveals an endosymbiont in a stage of genome reduction that is ... | 2011 | 22102823 |
| responses of the pea aphid transcriptome to infection by facultative symbionts. | serratia symbiotica is a facultative symbiont of pea aphids (acyrthosiphon pisum) that provides tolerance to heat stress. although the phenotypic effects of facultative symbionts upon hosts have been studied in some detail, little is known about the molecular and genomic basis of these interactions. previous studies show a large impact of s. symbiotica upon the aphid metabolome. whole-genome transcriptional profiling and next-generation sequencing demonstrated expression of 94% of refseq genes f ... | 2011 | 21382108 |
| massive genomic decay in serratia symbiotica, a recently evolved symbiont of aphids. | all vertically transmitted bacterial symbionts undergo a process of genome reduction over time, resulting in tiny, gene-dense genomes. comparison of genomes of ancient bacterial symbionts gives only limited information about the early stages in the transition from a free-living to symbiotic lifestyle because many changes become obscured over time. here, we present the genome sequence for the recently evolved aphid symbiont serratia symbiotica. the s. symbiotica genome exhibits several of the hal ... | 2011 | 21266540 |
| isolation, pure culture and characterization of serratia symbiotica, the r-type of secondary endosymbionts of the black bean aphid aphis fabae. | an intracellular symbiotic bacterium was isolated from the flora of a natural clone of the black bean aphid aphis fabae. the strain was able to grow freely in aerobic condition on a rich medium containing 1% of each of following substrates; dextrose, yeast extract and peptone of casein. pure culture was achieved through the use of solid-phase culture on the same medium and was designated cwbi-2.3t. 16s ribosomal dna sequence analysis revealed that cwbi-2.3t strain was a member of the gamma-3 sub ... | 2010 | 20870890 |
| aphid reproductive investment in response to mortality risks. | aphids are striking in their prodigious reproductive capacity and reliance on microbial endosymbionts, which provision their hosts with necessary amino acids and provide protection against parasites and heat stress. perhaps as a result of this bacterial dependence, aphids have limited immune function that may leave them vulnerable to bacterial pathogens. an alternative, non-immunological response that may be available to infected aphids is to increase reproduction, thereby ameliorating fitness l ... | 2010 | 20716370 |
| effects of facultative symbionts and heat stress on the metabolome of pea aphids. | we examined metabolite pools of pea aphids with different facultative symbiont infections, and characterized their effects on aphid metabolism in baseline and heat stress conditions. the bacterial symbiont serratia symbiotica protects aphid hosts from the detrimental results of heat stress and shields the obligate symbiont buchnera from effects of heat. we investigated whether broad effects on metabolism might correlate with this protection. both facultative symbiont infection and heat treatment ... | 2010 | 19907504 |
| two species of symbiotic bacteria present in the soybean aphid (hemiptera: aphididae). | aphids, which feed solely on plant phloem sap, have developed symbiotic associations with bacteria that provide them with the amino acids that are lacking in phloem. three soybean aphid (aphis glycines mat samura) populations were screened for the presence of buchnera aphidicola and three common species of secondary aphid symbionts (serratia symbiotica, hamiltonella defensa, and regiella insecticola). diagnostic polymerase chain reaction and subsequent dna sequencing showed the presence of two s ... | 2009 | 19791603 |
| a strain of the bacterial symbiont regiella insecticola protects aphids against parasitoids. | aphids commonly harbour facultative bacterial endosymbionts and may benefit from their presence through increased resistance to parasitoids. this has been demonstrated for hamiltonella defensa and serratia symbiotica, while a third common endosymbiont, regiella insecticola, did not provide such protection. however, this symbiont was recently detected in a highly resistant clone of the peach-potato aphid, myzus persicae, from australia. to test if resistance was indeed conferred by the endosymbio ... | 2010 | 19776066 |
| evolution and diversity of facultative symbionts from the aphid subfamily lachninae. | many aphids harbor a variety of endosymbiotic bacteria. the functions of these symbionts can range from an obligate nutritional role to a facultative role in protecting their hosts against environmental stresses. one such symbiont is "candidatus serratia symbiotica," which is involved in defense against heat and potentially also in aphid nutrition. lachnid aphids have been the focus of several recent studies investigating the transition of this symbiont from a facultative symbiont to an obligate ... | 2009 | 19542349 |
| evolution of the secondary symbiont "candidatus serratia symbiotica" in aphid species of the subfamily lachninae. | buchnera aphidicola bcc, the primary endosymbiont of the aphid cinara cedri (subfamily lachninae), is losing its symbiotic capacity and might be replaced by the coresident "candidatus serratia symbiotica." phylogenetic and morphological analyses within the subfamily lachninae indicate two different "ca. serratia symbiotica" lineages and support the longtime coevolution of both symbionts in c. cedri. | 2008 | 18502932 |
| role of host nutrition in symbiont regulation: impact of dietary nitrogen on proliferation of obligate and facultative bacterial endosymbionts of the pea aphid acyrthosiphon pisum. | the impact of host nutrition on symbiont regulation in the pea aphid acyrthosiphon pisum was investigated. the population density of the obligate symbiont buchnera aphidicola positively correlated with dietary nitrogen levels. in contrast, the population density of the facultative symbiont serratia symbiotica increased in aphids reared on low-nitrogen diets, indicating distinct regulatory mechanisms in the same insect host. | 2007 | 17158610 |
| costs and benefits of a superinfection of facultative symbionts in aphids. | symbiotic associations between animals and inherited micro-organisms are widespread in nature. in many cases, hosts may be superinfected with multiple inherited symbionts. acyrthosiphon pisum (the pea aphid) may harbour more than one facultative symbiont (called secondary symbionts) in addition to the obligate primary symbiont, buchnera aphidicola. previously we demonstrated that, in a controlled genetic background, a. pisum infected with either serratia symbiotica or hamiltonella defensa (calle ... | 2006 | 16720402 |
| whole-genome sequence of serratia symbiotica strain cwbi-2.3t, a free-living symbiont of the black bean aphid aphis fabae. | the gammaproteobacterium serratia symbiotica is one of the major secondary symbionts found in aphids. here, we report the draft genome sequence of s. symbiotica strain cwbi-2.3(t), previously isolated from the black bean aphid aphis fabae. the 3.58-mb genome sequence might provide new insights to understand the evolution of insect-microbe symbiosis. | 2014 | 25146134 |
| 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 |
| happens in the best of subfamilies: establishment and repeated replacements of co-obligate secondary endosymbionts within lachninae aphids. | virtually all aphids maintain an obligate mutualistic symbiosis with bacteria from the buchnera genus, which produce essential nutrients for their aphid hosts. most aphids from the lachninae subfamily have been consistently found to house additional endosymbionts, mainly serratia symbiotica. this apparent dependence on secondary endosymbionts was proposed to have been triggered by the loss of the riboflavin biosynthetic capability by buchnera in the lachninae last common ancestor. however, an in ... | 2017 | 27902872 |
| exploring the bacterial microbiota associated with native south american species of aphis (hemiptera: aphididae). | aphids harbor a variety of bacterial endosymbionts, including the obligate symbiont buchnera aphidicola and diverse facultative symbionts. the former supplies its host with essential amino acids. the latter are not indispensable for insect survival, but often improve their host's fitness. to date, the study of such associations was restricted to aphids of holarctic origin. the bacterial microbiota of seven aphis species from argentina was investigated. the presence of b. aphidicola was assessed ... | 2014 | 24736017 |
| 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 |
| assessment of a 16s rrna amplicon illumina sequencing procedure for studying the microbiome of a symbiont-rich aphid genus. | the bacterial communities inhabiting arthropods are generally dominated by a few endosymbionts that play an important role in the ecology of their hosts. rather than comparing bacterial species richness across samples, ecological studies on arthropod endosymbionts often seek to identify the main bacterial strains associated with each specimen studied. the filtering out of contaminants from the results and the accurate taxonomic assignment of sequences are therefore crucial in arthropod microbiom ... | 2016 | 26458227 |
| buchnera has changed flatmate but the repeated replacement of co-obligate symbionts is not associated with the ecological expansions of their aphid hosts. | symbiotic associations with bacteria have facilitated important evolutionary transitions in insects and resulted in long-term obligate interactions. recent evidence suggests that these associations are not always evolutionarily stable and that symbiont replacement, and/or supplementation of an obligate symbiosis by an additional bacterium, has occurred during the history of many insect groups. yet, the factors favouring one symbiont over another in this evolutionary dynamic are not well understo ... | 2016 | 27862540 |
| reinventing the wheel and making it round again: evolutionary convergence in buchnera-serratia symbiotic consortia between the distantly related lachninae aphids tuberolachnus salignus and cinara cedri. | virtually all aphids (aphididae) harbor buchnera aphidicola as an obligate endosymbiont to compensate nutritional deficiencies arising from their phloem diet. many species within the lachninae subfamily seem to be consistently associated also with serratia symbiotica we have previously shown that both cinara (cinara) cedri and cinara (cupressobium) tujafilina (lachninae: eulachnini tribe) have indeed established co-obligate associations with both buchnera and s. symbiotica however, while buchner ... | 2016 | 27190007 |
| seasonal changes in the endosymbiotic consortia of aphids from the genus cinara. | buchnera aphidicola is the primary endosymbiont of aphids with which it maintains an obligate mutualistic symbiotic relationship. insects also maintain facultative symbiotic relationships with secondary symbionts, and serratia symbiotica is the most common in aphids. the presence of both symbionts in aphids of the subfamily lachninae has been widely studied by our group. we examined two closely related aphids, cinara tujafilina and c. cedri in the present study. even though both b. aphidicola st ... | 2016 | 27297891 |
| 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 |
| ecological factors influencing the beneficial endosymbionts of the hemlock woolly adelgid (hemiptera: adelgidae). | bacterial endosymbionts of sap-sucking insects provide their host with a number of beneficial qualities, including the supply of nutrition, defense against parasitoids, and protection from heat stress. damage to these bacterial associates can therefore have a negative impact on the fitness of their insect host. we evaluated observational and experimental factors regarding the non-native hemlock woolly adelgid (adelges tsugae annand) (hemiptera: adelgidae) to help understand the roles of its thre ... | 2017 | 28791805 |
| toward a better understanding of the mechanisms of symbiosis: a comprehensive proteome map of a nascent insect symbiont. | symbiotic bacteria are common in insects and can affect various aspects of their hosts' biology. although the effects of insect symbionts have been clarified for various insect symbiosis models, due to the difficulty of cultivating them in vitro, there is still limited knowledge available on the molecular features that drive symbiosis. serratia symbiotica is one of the most common symbionts found in aphids. the recent findings of free-living strains that are considered as nascent partners of aph ... | 2017 | 28503376 |