scholarly journals Bacterial symbionts in insects or the story of communities affecting communities

2011 ◽  
Vol 366 (1569) ◽  
pp. 1389-1400 ◽  
Author(s):  
Julia Ferrari ◽  
Fabrice Vavre
Keyword(s):  
Bacterial Communities ◽  
Horizontal Transmission ◽  
Model Systems ◽  
Community Genetics ◽  
Bacterial Symbionts ◽  
Ideal Model ◽  
Host Genotype ◽  
Or Gene ◽  
Dynamic Communities ◽  
The Cost

Bacterial symbionts are widespread in insects and other animals. Most of them are predominantly vertically transmitted, along with their hosts' genes, and thus extend the heritable genetic variation present in one species. These passengers have a variety of repercussions on the host's phenotypes: besides the cost imposed on the host for maintaining the symbiont population, they can provide fitness advantages to the host or manipulate the host's reproduction. We argue that insect symbioses are ideal model systems for community genetics. First, bacterial symbionts directly or indirectly affect the interactions with other species within a community. Examples include their involvement in modifying the use of host plants by phytophagous insects, in providing resistance to natural enemies, but also in reducing the global genetic diversity or gene flow between populations within some species. Second, one emerging picture in insect symbioses is that many species are simultaneously infected with more than one symbiont, which permits studying the factors that shape bacterial communities; for example, horizontal transmission, interactions between host genotype, symbiont genotype and the environment and interactions among symbionts. One conclusion is that insects' symbiotic complements are dynamic communities that affect and are affected by the communities in which they are embedded.

scholarly journals The Importance of Environmentally Acquired Bacterial Symbionts for the Squash Bug (Anasa tristis), a Significant Agricultural Pest

2021 ◽  
Vol 12 ◽  
Author(s):  
Tarik S. Acevedo ◽  
Gregory P. Fricker ◽  
Justine R. Garcia ◽  
Tiffanie Alcaide ◽  
Aileen Berasategui ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Horizontal Transmission ◽  
Bacterial Symbionts ◽  
Complete Understanding ◽  
Anasa Tristis ◽  
Squash Bug ◽  
The Family ◽  
Insect Symbionts ◽  
Midgut Crypts ◽  
Bacterial Plant Pathogen

Most insects maintain associations with microbes that shape their ecology and evolution. Such symbioses have important applied implications when the associated insects are pests or vectors of disease. The squash bug, Anasa tristis (Coreoidea: Coreidae), is a significant pest of human agriculture in its own right and also causes damage to crops due to its capacity to transmit a bacterial plant pathogen. Here, we demonstrate that complete understanding of these insects requires consideration of their association with bacterial symbionts in the family Burkholderiaceae. Isolation and sequencing of bacteria housed in the insects’ midgut crypts indicates that these bacteria are consistent and dominant members of the crypt-associated bacterial communities. These symbionts are closely related to Caballeronia spp. associated with other true bugs in the superfamilies Lygaeoidea and Coreoidea. Fitness assays with representative Burkholderiaceae strains indicate that the association can significantly increase survival and decrease development time, though strains do vary in the benefits that they confer to their hosts, with Caballeronia spp. providing the greatest benefit. Experiments designed to assess transmission mode indicate that, unlike many other beneficial insect symbionts, the bacteria are not acquired from parents before or after hatching but are instead acquired from the environment after molting to a later developmental stage. The bacteria do, however, have the capacity to escape adults to be transmitted to later generations, leaving the possibility for a combination of indirect vertical and horizontal transmission.

scholarly journals The dilution effect limits plasmid horizontal transmission in multispecies bacterial communities

Microbiology ◽  
2021 ◽  
Vol 167 (9) ◽  
Author(s):  
Anastasia Kottara ◽  
Laura Carrilero ◽  
Ellie Harrison ◽  
James P. J. Hall ◽  
Michael A. Brockhurst
Keyword(s):  
Host Species ◽  
Bacterial Communities ◽  
Horizontal Transmission ◽  
Dilution Effect ◽  
Infection Risk ◽  
Host Cells ◽  
Evolutionary Innovation ◽  
Genomic Divergence ◽  
Plasmid Diversity ◽  
Plasmid Conjugation

By transferring ecologically important traits between species, plasmids drive genomic divergence and evolutionary innovation in their bacterial hosts. Bacterial communities are often diverse and contain multiple coexisting plasmids, but the dynamics of plasmids in multi-species communities are poorly understood. Here, we show, using experimental multi-species communities containing two plasmids, that bacterial diversity limits the horizontal transmission of plasmids due to the ‘dilution effect’; this is an epidemiological phenomenon whereby living alongside less proficient host species reduces the expected infection risk for a focal host species. In addition, plasmid horizontal transmission was also affected by plasmid diversity, such that the rate of plasmid conjugation was reduced from co-infected host cells carrying both plasmids. In diverse microbial communities, plasmid spread may be limited by the dilution effect and plasmid–plasmid interactions, reducing the rate of horizontal transmission.

scholarly journals On mechanisms of trophic cascade caused by anti-predation response in food chain systems

2020 ◽  
Vol 1 (2) ◽  
pp. 1-27
Author(s):  
Yang Wang ◽  
Xingfu Zou
Keyword(s):  
Food Chain ◽  
Trophic Cascade ◽  
Predation Rate ◽  
Model Systems ◽  
Large Carnivores ◽  
Response Level ◽  
Population Sizes ◽  
The Cost ◽  
The Impact ◽  
D Model

Motivated by a recent field study [Nat. Commun. 7(2016), 10698] on the impact of fear of large carnivores on the populations in a cascading ecosystem of food chain type with the large carnivores as the top predator, in this paper we propose two model systems in the form of ordinary differential equations to mechanistically explore the cascade of such a fear effect. The models are of the Lotka-Volterra type, one is three imensional and the other four dimensional. The 3-D model only considers the cost of the anti-predation response reflected in the decrease of the production, while the 4-D model considers also the benefit of the response in reducing the predation rate, in addition to the cost by reducing the production. We perform a thorough analysis on the dynamics of the two models. The results reveal that the 3-D model and 4-model demonstrate opposite patterns for trophic cascade in terms of the dependence of population sizes for each species at the co-existence equilibrium on the anti-predation response level parameter, and such a difference is attributed to whether or not there is a benefit for the anti-predation response by the meso-carnivore species.

scholarly journals Endophytic bacterial communities of oilseed rape associate with genotype-specific resistance against Verticillium longisporum

2019 ◽  
Vol 96 (1) ◽  
Author(s):  
Stefanie P Glaeser ◽  
Iulian Gabur ◽  
Hossein Haghighi ◽  
Jens-Ole Bartz ◽  
Peter Kämpfer ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Relative Abundance ◽  
Bacterial Communities ◽  
Quantitative Resistance ◽  
Bacterial Community Composition ◽  
Phylogenetic Group ◽  
Rrna Gene ◽  
Host Genotype ◽  
Brassica Napus L ◽  
Verticillium Longisporum

ABSTRACT Associations of endophytic bacterial community composition of oilseed rape (Brassica napus L.) with quantitative resistance against the soil-borne fungal pathogen Verticillium longisporum was assessed by 16S rRNA gene amplicon sequencing in roots and hypocotyls of four plant lines with contrasting genetic composition in regard to quantitative resistance reactions. The plant compartment was found to be the dominating driving factor for the specificity of bacterial communities in healthy plants. Furthermore, V. longisporum infection triggered a stabilization of phylogenetic group abundance in replicated samples suggesting a host genotype-specific selection. Genotype-specific associations with bacterial phylogenetic group abundance were identified by comparison of plant genotype groups (resistant versus susceptible) and treatment groups (healthy versus V. longisporum-infected) allowing dissection into constitutive and induced directional association patterns. Relative abundance of Flavobacteria, Pseudomonas, Rhizobium and Cellvibrio was associated with resistance/susceptibility. Relative abundance of Flavobacteria and Cellvibrio was increased in resistant genotypes according to their known ecological functions. In contrast, a higher relative abundance of Pseudomonas and Rhizobium, which are known to harbor many species with antagonistic properties to fungal pathogens, was found to be associated with susceptibility, indicating that these groups do not play a major role in genetically controlled resistance of oilseed rape against V. longisporum.

scholarly journals Negative Fitness Consequences and Transmission Dynamics of a Heritable Fungal Symbiont of a Parasitic Wasp

2009 ◽  
Vol 75 (10) ◽  
pp. 3115-3119 ◽  
Author(s):  
Cara M. Gibson ◽  
Martha S. Hunter
Keyword(s):  
Competitive Ability ◽  
Horizontal Transmission ◽  
Parasitic Wasp ◽  
Experimental Tests ◽  
Bacterial Symbionts ◽  
Fitness Costs ◽  
Fungal Symbiont ◽  
Fitness Consequences ◽  
Single Host ◽  
Host Ecology

ABSTRACT Heritable bacterial symbionts are widespread in insects and can have many important effects on host ecology and fitness. Fungal symbionts are also important in shaping their hosts' behavior, interactions, and evolution, but they have been largely overlooked. Experimental tests to determine the relevance of fungal symbionts to their insect hosts are currently extremely rare, and to our knowledge, there have been no such tests for strictly predacious insects. We investigated the fitness consequences for a parasitic wasp (Comperia merceti) of an inherited fungal symbiont in the Saccharomycotina (Ascomycota) that was long presumed to be a mutualist. In comparisons of wasp lines with and without this symbiont, we found no evidence of mutualism. Instead, there were significant fitness costs to the wasps in the presence of the yeast; infected wasps attacked fewer hosts and had longer development times. We also examined the relative competitive abilities of the larval progeny of infected and uninfected mothers, as well as horizontal transmission of the fungal symbiont among larval wasps that shared a single host cockroach egg case. We found no difference in larval competitive ability when larvae whose infection status differed shared a single host. We did find high rates of horizontal transmission of the fungus, and we suggest that this transmission is likely responsible for the maintenance of this infection in wasp populations.

Transitions in symbiosis: evidence for environmental acquisition & social transmission within a clade of heritable symbionts

2020 ◽  
Author(s):  
Georgia C Drew ◽  
Giles E Budge ◽  
Crystal L Frost ◽  
Peter Neumann ◽  
Stefanos Siozios ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Fluorescent In Situ Hybridization ◽  
Horizontal Transmission ◽  
Bacterial Symbionts ◽  
Free Living ◽  
Social Contacts ◽  
Obligate Mutualism ◽  
Environmental Microbes

AbstractA dynamic continuum exists from free-living environmental microbes to strict host associated symbionts that are vertically inherited. However, knowledge of the forces that drive transitions in the modes by which symbioses form is lacking. Arsenophonus is a diverse clade of bacterial symbionts, comprising reproductive parasites to coevolving obligate mutualists, in which the predominant mode of transmission is vertical. We describe a symbiosis between a member of the genus Arsenophonus and the Western honey bee. We then present multiple lines of evidence that this symbiont deviates from a heritable model of transmission. Field sampling uncovered marked spatial and seasonal dynamics in symbiont prevalence, and rapid infection loss events were observed in field colonies and individuals in the laboratory. Fluorescent in-situ hybridization showed Arsenophonus localised in the gut, and detection of the bacterium was rare in screens of early honey bee life stages. We directly show horizontal transmission of Arsenophonus between bees under varying social conditions. We conclude that honey bees acquire Arsenophonus through a combination of environmental exposure and social contacts. Together these findings uncover a key link in the Arsenophonus clades trajectory from free-living ancestral life to obligate mutualism, and provide a foundation for studying transitions in symbiotic lifestyle.

Age, gut location and diet impact the gut microbiome of a tropical herbivorous surgeonfish

2019 ◽  
Author(s):  
Lara Parata ◽  
Shaun Nielsen ◽  
Xing Xing ◽  
Torsten Thomas ◽  
Suhelen Egan ◽  
...  
Keyword(s):  
Coral Reef ◽  
Gastrointestinal Tract ◽  
Bacterial Community ◽  
Gut Microbiota ◽  
Bacterial Communities ◽  
Food Source ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Bacterial Symbionts ◽  
Adult Fish

Abstract Herbivorous fishes play important ecological roles in coral reefs by consuming algae that can otherwise outcompete corals, but we know little about the gut microbiota that facilitates this process. This study focussed on the gut microbiota of an ecologically important coral reef fish, the convict surgeonfish Acanthurus triostegus. We sought to understand how the microbiome of this species varies along its gastrointestinal tract and how it varies between juvenile and adult fish. Further, we examined if the bacteria associated with the diet consumed by juveniles contributes to the gut microbiota. 16S rRNA gene amplicon sequencing showed that bacterial communities associated with the midgut and hindgut regions were distinct between adults and juveniles, however, no significant differences were seen for gut wall samples. The microbiota associated with the epilithic algal food source was similar to that of the juvenile midgut and gut wall but differed from the microbiome of the hindgut. A core bacterial community including members of taxa Epulopiscium and Brevinemataceae was observed across all gastrointestinal and diet samples, suggesting that these bacterial symbionts can be acquired by juvenile convict surgeonfish horizontally via their diet and then are retained into adulthood.

scholarly journals Bacteria regulate choanoflagellate development with lipid activators, inhibitors, and synergists

2016 ◽  
Author(s):  
Arielle Woznica ◽  
Alexandra M. Cantley ◽  
Christine Beemelmanns ◽  
Elizaveta Freinkman ◽  
Jon Clardy ◽  
...  
Keyword(s):  
Model Systems ◽  
Bacterial Symbionts ◽  
Bioactive Lipids ◽  
Multicellular Development ◽  
Complex Interactions ◽  
Environmental Bacteria ◽  
Animal Hosts ◽  
Inducing Factors ◽  
Insight Into ◽  
Relevant Interaction

AbstractIn choanoflagellates, the closest living relatives of animals, multicellular “rosette” development is regulated by environmental bacteria. The simplicity of this evolutionarily-relevant interaction provides an opportunity to identify the molecules and regulatory logic underpinning bacterial regulation of development. We find that the rosette-inducing bacterium Algoriphagus machipongonensis produces three structurally divergent classes of bioactive lipids that, together, activate, enhance, and inhibit rosette development in the choanoflagellate S. rosetta. One class of molecules, the lysophosphatidylethanolamines (LPEs), elicits no response on its own, but synergizes with activating sulfonolipid rosette inducing factors (RIFs) to recapitulate the full bioactivity of live Algoriphagus. LPEs, while ubiquitous in bacteria and eukaryotes, have not previously been implicated in the regulation of a host-microbe interaction. This study reveals that multiple bacterially-produced lipids converge to activate, enhance, and inhibit multicellular development in a choanoflagellate.Significance StatementBacterial symbionts profoundly influence the biology of their animal hosts, yet complex interactions between animals and their resident bacteria often make it challenging to characterize the molecules and mechanisms. Simple model systems can reveal fundamental processes underlying interactions between eukaryotes and their associated microbial communities, and provide insight into how bacteria regulate animal biology. In this study we isolate and characterize bacterial molecules that regulate multicellular development in the closest living relatives of animals, the choanoflagellate. We find that multiple bacterially-derived lipids converge to activate, enhance, and inhibit choanoflagellate multicellular development.

scholarly journals Evaluation of a new probiotic concept for broilers

2020 ◽  
Author(s):  
S. L. Jørgensen ◽  
L. L. Poulsen ◽  
M. Bisgaard ◽  
H. Christensen
Keyword(s):  
Pathogenic Bacteria ◽  
Horizontal Transmission ◽  
Lactobacillus Rhamnosus ◽  
Probiotic Strain ◽  
Average Weight ◽  
Normal Range ◽  
Multiple Introductions ◽  
E Coli ◽  
Probiotic Strains ◽  
The Cost

SUMMARYProbiotics were introduced as a spray directly in the hatcher when chickens started to leave the eggs which potentially could reduce the horizontal transmission and colonization with pathogenic bacteria. The single introduction of probiotics could limit the cost compared to multiple introductions with feed and/or water. A mixture of five probiotic strains belonging to Escherichia coli, Enterococcus faecalis, Lactobacillus agilis and Lactobacillus rhamnosus was tested with two independent flocks of broilers (Ross 308). For each experiment, a comparison was made to an untreated control flock on the same farm. At day 14 of production the probiotic strains were re-isolated from ileum of euthanized chickens. The first week mortality was slightly increased in the probiotic flock (0.42%) compared to the control (0.35%) in experiment 1, however, it was higher in the control flock (1.45%) compared to the probiotic flock (1.12%) in experiment 2. The average weight of chickens that could be slaughtered for consumption was increased by 3.5% in the probiotic flocks compared to the control flocks, resulting in a 1.9% higher total weight of slaughtered chickens in the probiotics treated flocks compared to the control as a mean of the two experiments. The number of condemned animals was within the normal range for the production system and could not directly be related to effects of probiotics. Although one probiotic strain of E. coli was isolated from dead animals, the probiotics did not affect the proportion of chickens which died due to E. coli during the first week compared to the control.Primary audienceplant managers, veterinarians, nutritionists

scholarly journals The importance of environmentally-acquired bacterial symbionts for the squash bug (Anasa tristis), a significant agricultural pest

2021 ◽  
Author(s):  
Tarik S. Acevedo ◽  
Gregory P. Fricker ◽  
Justine R Garcia ◽  
Tiffany Alcaide ◽  
Aileen Berasategui ◽  
...  
Keyword(s):  
Horizontal Transmission ◽  
Development Stage ◽  
Bacterial Symbionts ◽  
Complete Understanding ◽  
Anasa Tristis ◽  
Squash Bug ◽  
The Family ◽  
Insect Symbionts ◽  
Midgut Crypts ◽  
Bacterial Plant Pathogen

Most insects maintain associations with microbes that shape their ecology and evolution. Such symbioses have important applied implications when the associated insects are pests or vectors of disease. The squash bug, Anasa tristis (Coreoidea: Coreidae), is a significant pest of human agriculture in its own right and also causes damage to crops due to its capacity to transmit a bacterial plant pathogen. Here, we demonstrate that complete understanding of these insects requires consideration of their association with bacterial symbionts in the family Burkholderiaceae. Isolation and sequencing of bacteria housed in midgut crypts in these insects indicates that these bacteria are consistent and dominant members of the crypt-associated bacterial communities. These symbionts are closely related to Caballeronia spp. associated other true bugs in the superfamiles Lygaeoidea and Coreoidea. Fitness assays with representative Burkholderiaceae strains indicate that the association can significantly increase survival and decrease development time, though strains do vary in the benefits that they confer to their hosts, with Caballeronia spp. providing the greatest benefit. Experiments designed to assess transmission mode indicate that unlike many other beneficial insect symbionts, the bacteria are not acquired from parents before or after hatching but are instead acquired from the environment after molting to a later development stage. The bacteria do, however, have the capacity to escape adults to be transmitted to later generations, leaving the possibility for a combination of indirect vertical and horizontal transmission.

Sign in / Sign up

Export Citation Format

Share Document