scholarly journals Predicting distributions of Wolbachia strains through host ecological contact -- who's manipulating whom?

2021 ◽  
Author(s):  
Clive Darwell ◽  
Daniel Souto-Villaros ◽  
Jan Michalek ◽  
Sotiria Boutsi ◽  
Brus Iusa ◽  
...  
Keyword(s):  
Cytoplasmic Incompatibility ◽  
Wolbachia Infection ◽  
Sympatric Species ◽  
Third Party ◽  
Ecological Context ◽  
Fig Wasps ◽  
Hybrid Fitness ◽  
Trade Off ◽  
Predictive Algorithm ◽  
Offspring Mortality

Barriers to gene-flow within populations, typically in response to divergent selection, are often mediated via third-party interactions. Under these conditions speciation is inextricably linked to ecological context. We present a novel framework for studying arthropod speciation as mediated by Wolbachia, a microbial endosymbiont capable of causing host cytoplasmic incompatibility (CI) via alternative strain associations. Building on empirical findings, our model predicts that sympatric host sister-species harbour paraphyletic strains that provide CI, while well-defined congeners in ecological contact and recently diverged noninteracting congeners are uninfected due to Wolbachia redundancy. We argue that Wolbachia may provide an adaptive advantage when coupled with reduced hybrid fitness (via trait mismatching), by facilitating assortative mating between co-occurring divergent phenotypes – the contact contingency hypothesis. To test this, we applied a custom-built predictive algorithm to empirical data from host-specific pollinating fig wasps, achieving ≤88.46% accuracy. We then considered post-zygotic offspring mortality during CI matings by developing a model featuring fitness clines across oviposition resources. This oviposition trade-off model, tested through simulation, favoured CI at realistic conspecific mating frequencies despite fecundity losses. We demonstrate that a rules-based algorithm accurately predicts Wolbachia infection status. This has implications among other systems where closely-related sympatric species encounter adaptive disadvantage through hybridisation.

scholarly journals Predicting distributions of Wolbachia strains through host ecological contact -- who's manipulating whom?

2021 ◽  
Author(s):  
Clive Darwell ◽  
Daniel Souto-Vilaros ◽  
Jan Michalek ◽  
Sotiria Boutsi ◽  
Brus Iusa ◽  
...  
Keyword(s):  
Cytoplasmic Incompatibility ◽  
Sympatric Species ◽  
Third Party ◽  
Infection Status ◽  
Ecological Context ◽  
Fig Wasps ◽  
Hybrid Fitness ◽  
Trade Off ◽  
Predictive Algorithm ◽  
Offspring Mortality

Barriers to gene-flow within populations, typically in response to divergent selection, are often mediated via third-party interactions. Under these conditions speciation is inextricably linked to ecological context. We present a novel framework for studying arthropod speciation as mediated by Wolbachia, a microbial endosymbiont capable of causing host cytoplasmic incompatibility (CI) via alternative strain associations. Building on empirical findings, our model predicts that sympatric host sister-species harbour paraphyletic strains that provide CI, while well-defined congeners in ecological contact and recently diverged noninteracting congeners are uninfected due to Wolbachia redundancy. We argue that Wolbachia may provide an adaptive advantage when coupled with reduced hybrid fitness (via trait mismatching), by facilitating assortative mating between co-occurring divergent phenotypes – the contact contingency hypothesis. To test this, we applied a custom-built predictive algorithm to empirical data from host-specific pollinating fig wasps, achieving ≤88.46% accuracy. We then considered post-zygotic offspring mortality during CI matings by developing a model featuring fitness clines across oviposition resources. This oviposition trade-off model, tested through simulation, favoured CI at realistic conspecific mating frequencies despite fecundity losses. We demonstrate that a rules-based algorithm accurately predicts Wolbachia infection status. This has implications among other systems where closely-related sympatric species encounter adaptive disadvantage through hybridisation.

scholarly journals Predicting distributions of Wolbachia strains through host ecological contact -- who's manipulating whom?

2021 ◽  
Author(s):  
Clive Darwell ◽  
Daniel Souto-Vilaros ◽  
Jan Michalek ◽  
Sotiria Boutsi ◽  
Brus Iusa ◽  
...  
Keyword(s):  
Cytoplasmic Incompatibility ◽  
Sympatric Species ◽  
Third Party ◽  
Infection Status ◽  
Ecological Context ◽  
Fig Wasps ◽  
Hybrid Fitness ◽  
Trade Off ◽  
Predictive Algorithm ◽  
Offspring Mortality

Barriers to gene-flow within populations, typically in response to divergent selection, are often mediated via third-party interactions. Under these conditions speciation is inextricably linked to ecological context. We present a novel framework for studying arthropod speciation as mediated by Wolbachia, a microbial endosymbiont capable of causing host cytoplasmic incompatibility (CI) via alternative strain associations. Building on empirical findings, our model predicts that sympatric host sister-species harbour paraphyletic strains that provide CI, while well-defined congeners in ecological contact and recently diverged noninteracting congeners are uninfected due to Wolbachia redundancy. We argue that Wolbachia may provide an adaptive advantage when coupled with reduced hybrid fitness (via trait mismatching), by facilitating assortative mating between co-occurring divergent phenotypes – the contact contingency hypothesis. To test this, we applied a custom-built predictive algorithm to empirical data from host-specific pollinating fig wasps, achieving ≤88.46% accuracy. We then considered post-zygotic offspring mortality during CI matings by developing a model featuring fitness clines across oviposition resources. This oviposition trade-off model, tested through simulation, favoured CI at realistic conspecific mating frequencies despite fecundity losses. We demonstrate that a rules-based algorithm accurately predicts Wolbachia infection status. This has implications among other systems where closely-related sympatric species encounter adaptive disadvantage through hybridisation.

Wolbachia and Cytoplasmic Incompatibility in the CaliforniaCulex pipiensMosquito Species Complex: Parameter Estimates and Infection Dynamics in Natural Populations

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 2029-2038 ◽  
Author(s):  
Jason L Rasgon ◽  
Thomas W Scott
Keyword(s):  
Species Complex ◽  
Cytoplasmic Incompatibility ◽  
Natural Populations ◽  
Wolbachia Infection ◽  
Field Conditions ◽  
Parameter Estimates ◽  
Infection Prevalence ◽  
Infection Frequency ◽  
Specific Pcr ◽  
Vector Borne

AbstractBefore maternally inherited bacterial symbionts like Wolbachia, which cause cytoplasmic incompatibility (CI; reduced hatch rate) when infected males mate with uninfected females, can be used in a program to control vector-borne diseases it is essential to understand their dynamics of infection in natural arthropod vector populations. Our study had four goals: (1) quantify the number of Wolbachia strains circulating in the California Culex pipiens species complex, (2) investigate Wolbachia infection frequencies and distribution in natural California populations, (3) estimate the parameters that govern Wolbachia spread among Cx. pipiens under laboratory and field conditions, and (4) use these values to estimate equilibrium levels and compare predicted infection prevalence levels to those observed in nature. Strain-specific PCR, wsp gene sequencing, and crossing experiments indicated that a single Wolbachia strain infects Californian Cx. pipiens. Infection frequency was near or at fixation in all populations sampled for 2 years along a >1000-km north-south transect. The combined statewide infection frequency was 99.4%. Incompatible crosses were 100% sterile under laboratory and field conditions. Sterility decreased negligibly with male age in the laboratory. Infection had no significant effect on female fecundity under laboratory or field conditions. Vertical transmission was >99% in the laboratory and ∼98.6% in the field. Using field data, models predicted that Wolbachia will spread to fixation if infection exceeds an unstable equilibrium point above 1.4%. Our estimates accurately predicted infection frequencies in natural populations. If certain technical hurdles can be overcome, our data indicate that Wolbachia can invade vector populations as part of an applied transgenic strategy for vector-borne disease reduction.

scholarly journals The Biochemistry of Cytoplasmic Incompatibility Caused by Endosymbiotic Bacteria

Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 852
Author(s):  
Hongli Chen ◽  
Mengwen Zhang ◽  
Mark Hochstrasser
Keyword(s):  
Molecular Mechanisms ◽  
Protein Pair ◽  
Cytoplasmic Incompatibility ◽  
Wolbachia Infection ◽  
Threshold Level ◽  
Upstream Gene ◽  
Arthropod Species ◽  
Bacterial Endosymbionts ◽  
Inducing Factors ◽  
New Research

Many species of arthropods carry maternally inherited bacterial endosymbionts that can influence host sexual reproduction to benefit the bacterium. The most well-known of such reproductive parasites is Wolbachia pipientis. Wolbachia are obligate intracellular α-proteobacteria found in nearly half of all arthropod species. This success has been attributed in part to their ability to manipulate host reproduction to favor infected females. Cytoplasmic incompatibility (CI), a phenomenon wherein Wolbachia infection renders males sterile when they mate with uninfected females, but not infected females (the rescue mating), appears to be the most common. CI provides a reproductive advantage to infected females in the presence of a threshold level of infected males. The molecular mechanisms of CI and other reproductive manipulations, such as male killing, parthenogenesis, and feminization, have remained mysterious for many decades. It had been proposed by Werren more than two decades ago that CI is caused by a Wolbachia-mediated sperm modification and that rescue is achieved by a Wolbachia-encoded rescue factor in the infected egg. In the past few years, new research has highlighted a set of syntenic Wolbachia gene pairs encoding CI-inducing factors (Cifs) as the key players for the induction of CI and its rescue. Within each Cif pair, the protein encoded by the upstream gene is denoted A and the downstream gene B. To date, two types of Cifs have been characterized based on the enzymatic activity identified in the B protein of each protein pair; one type encodes a deubiquitylase (thus named CI-inducing deubiquitylase or cid), and a second type encodes a nuclease (named CI-inducing nuclease or cin). The CidA and CinA proteins bind tightly and specifically to their respective CidB and CinB partners. In transgenic Drosophila melanogaster, the expression of either the Cid or Cin protein pair in the male germline induces CI and the expression of the cognate A protein in females is sufficient for rescue. With the identity of the Wolbachia CI induction and rescue factors now known, research in the field has turned to directed studies on the molecular mechanisms of CI, which we review here.

scholarly journals Limited intrinsic postzygotic reproductive isolation despite chromosomal rearrangements between closely related sympatric species of small ermine moths (Lepidoptera: Yponomeutidae)

2019 ◽  
Vol 128 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Katerina H Hora ◽  
František Marec ◽  
Peter Roessingh ◽  
Steph B J Menken
Keyword(s):  
Reproductive Isolation ◽  
Parental Species ◽  
Meiotic Chromosome ◽  
Chromosomal Rearrangements ◽  
Sympatric Species ◽  
Hybrid Fitness ◽  
New Host ◽  
Closely Related Species ◽  
Postzygotic Reproductive Isolation

Abstract In evolutionarily young species and sympatric host races of phytophagous insects, postzygotic incompatibility is often not yet fully developed, but reduced fitness of hybrids is thought to facilitate further divergence. However, empirical evidence supporting this hypothesis is limited. To assess the role of reduced hybrid fitness, we studied meiosis and fertility in hybrids of two closely related small ermine moths, Yponomeuta padella and Yponomeuta cagnagella, and determined the extent of intrinsic postzygotic reproductive isolation. We found extensive rearrangements between the karyotypes of the two species and irregularities in meiotic chromosome pairing in their hybrids. The fertility of reciprocal F1 and, surprisingly, also of backcrosses with both parental species was not significantly decreased compared with intraspecific offspring. The results indicate that intrinsic postzygotic reproductive isolation between these closely related species is limited. We conclude that the observed chromosomal rearrangements are probably not the result of an accumulation of postzygotic incompatibilities preventing hybridization. Alternative explanations, such as adaptation to new host plants, are discussed.

scholarly journals Wolbachia infection reduces sperm competitive ability in an insect

2006 ◽  
Vol 273 (1593) ◽  
pp. 1455-1458 ◽  
Author(s):  
Fleur E Champion de Crespigny ◽  
Nina Wedell
Keyword(s):  
Population Dynamics ◽  
Sperm Competition ◽  
Empirical Evidence ◽  
Reproductive Strategies ◽  
Competitive Ability ◽  
Cytoplasmic Incompatibility ◽  
Wolbachia Infection ◽  
Sperm Production ◽  
Fitness Costs ◽  
Wolbachia Pipientis

The maternally inherited bacterium Wolbachia pipientis imposes significant fitness costs on its hosts. One such cost is decreased sperm production resulting in reduced fertility of male Drosophila simulans infected with cytoplasmic incompatibility (CI) inducing Wolbachia . We tested the hypothesis that Wolbachia infection affects sperm competitive ability and found that Wolbachia infection is indeed associated with reduced success in sperm competition in non-virgin males. In the second male role, infected males sired 71% of the offspring whereas uninfected males sired 82% of offspring. This is the first empirical evidence indicating that Wolbachia infection deleteriously affects sperm competition and raises the possibility that polyandrous females can utilize differential sperm competitive ability to bias the paternity of broods and avoid the selfish manipulations of Wolbachia . This suggests a relationship between Wolbachia infection and host reproductive strategies. These findings also have important consequences for Wolbachia population dynamics because the transmission advantage of Wolbachia is likely to be undermined by sperm competition.

scholarly journals High Incidence of Related Wolbachia across Unrelated Leaf-Mining Diptera

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 788
Author(s):  
Xuefen Xu ◽  
Peter M. Ridland ◽  
Paul A. Umina ◽  
Alex Gill ◽  
Perran A. Ross ◽  
...  
Keyword(s):  
Horizontal Transfer ◽  
Cytoplasmic Incompatibility ◽  
Wolbachia Infection ◽  
Wolbachia Pipientis ◽  
Reciprocal Crosses ◽  
Gene Set ◽  
Incompatible Insect Technique ◽  
Leaf Mining ◽  
High Incidence ◽  
Wolbachia Density

The maternally inherited endosymbiont, Wolbachia pipientis, plays an important role in the ecology and evolution of many of its hosts by affecting host reproduction and fitness. Here, we investigated 13 dipteran leaf-mining species to characterize Wolbachia infections and the potential for this endosymbiont in biocontrol. Wolbachia infections were present in 12 species, including 10 species where the Wolbachia infection was at or near fixation. A comparison of Wolbachia relatedness based on the wsp/MLST gene set showed that unrelated leaf-mining species often shared similar Wolbachia, suggesting common horizontal transfer. We established a colony of Liriomyza brassicae and found adult Wolbachia density was stable; although Wolbachia density differed between the sexes, with females having a 20-fold higher density than males. Wolbachia density increased during L. brassicae development, with higher densities in pupae than larvae. We removed Wolbachia using tetracycline and performed reciprocal crosses between Wolbachia-infected and uninfected individuals. Cured females crossed with infected males failed to produce offspring, indicating that Wolbachia induced complete cytoplasmic incompatibility in L. brassicae. The results highlight the potential of Wolbachia to suppress Liriomyza pests based on approaches such as the incompatible insect technique, where infected males are released into populations lacking Wolbachia or with a different incompatible infection.

scholarly journals FACTORS WHICH INFLUENCE LIQUID ASSETS IN SHARIA BANKS: A CASE STUDY OF PT BANK SYARIAH MANDIRI 2016-2017

2020 ◽  
Vol 9 (2) ◽  
pp. 133
Author(s):  
Taryana Harun
Keyword(s):  
Financial Market ◽  
Market Access ◽  
Third Party ◽  
Liquidity Management ◽  
Reserve Requirement ◽  
Trade Off ◽  
Independent Variables ◽  
Dual Regression ◽  
Lost Opportunity

Banks manage liquidity carefully because of differences in fund tenor collected and channeled. Meanwhile, at the same time, it must fulfill transaction needs, reserve requirement, current liabilities, and be cautious in facing sudden liquidity needs. Therefore, bankshold a sufficient amount of liquid assets. Liquidity management tends to be a trade-off. On one side, insufficient liquid assets can cause banks to be unable to carry out transactions with its customers or fulfill its maturity obligations. On another side, high liquid assets can result in a lost opportunity, because the liquid assets do not provide a return. The purpose of this research is to analyze what factors influence the level of banks liquid assets. This research was conducted using a dual regression model to analyze the variables studied, with a case study of PT Bank Syariah Mandiri from 2016-2017.The dependent variable was the level of liquid assets. Meanwhile, the independent variables were the amount of third party funds, financing growth, financial market access between banks, current liabilities, and previous month profit. The research results reveal that two variables are statistically significant towards bank liquid assets, which are third-party funds and previous month profit. Third-party funds and previous month profit have a positive and significat influence towards liquid assets. Meanwhile, the other variables do not significantly determined liquid assets.

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