Limits...
Should Symbionts Be Nice or Selfish? Antiviral Effects of Wolbachia Are Costly but Reproductive Parasitism Is Not.

Martinez J, Ok S, Smith S, Snoeck K, Day JP, Jiggins FM - PLoS Pathog. (2015)

Bottom Line: Symbionts can have mutualistic effects that increase their host's fitness and/or parasitic effects that reduce it.Strong antiviral protection is associated with substantial reductions in other fitness-related traits, whereas no such trade-off was detected for cytoplasmic incompatibility.The reason for this difference is likely that antiviral protection requires high symbiont densities but cytoplasmic incompatibility does not.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, University of Cambridge, Cambridge, United Kingdom.

ABSTRACT
Symbionts can have mutualistic effects that increase their host's fitness and/or parasitic effects that reduce it. Which of these strategies evolves depends in part on the balance of their costs and benefits to the symbiont. We have examined these questions in Wolbachia, a vertically transmitted endosymbiont of insects that can provide protection against viral infection and/or parasitically manipulate its hosts' reproduction. Across multiple symbiont strains we find that the parasitic phenotype of cytoplasmic incompatibility and antiviral protection are uncorrelated. Strong antiviral protection is associated with substantial reductions in other fitness-related traits, whereas no such trade-off was detected for cytoplasmic incompatibility. The reason for this difference is likely that antiviral protection requires high symbiont densities but cytoplasmic incompatibility does not. These results are important for the use of Wolbachia to block dengue virus transmission by mosquitoes, as natural selection to reduce these costs may lead to reduced symbiont density and the loss of antiviral protection.

No MeSH data available.


Related in: MedlinePlus

Wolbachia tissue tropism.Mean Wolbachia density in (A) head and thorax of females, (B) testes and (C) freshly laid eggs. Error bars are standard errors. Letters indicate significant differences based on a Tukey’s honest significance test on ln-transformed data. All tissues were analyzed in a single linear model to test for difference in tissue tropism: strain effect: F15,427 = 131. 1; P < 0.0001; tissue effect: F2,427 = 4448. 8; P < 0.0001; strain × tissue effect: F30,427 = 11.5; P < 0.0001.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4488530&req=5

ppat.1005021.g005: Wolbachia tissue tropism.Mean Wolbachia density in (A) head and thorax of females, (B) testes and (C) freshly laid eggs. Error bars are standard errors. Letters indicate significant differences based on a Tukey’s honest significance test on ln-transformed data. All tissues were analyzed in a single linear model to test for difference in tissue tropism: strain effect: F15,427 = 131. 1; P < 0.0001; tissue effect: F2,427 = 4448. 8; P < 0.0001; strain × tissue effect: F30,427 = 11.5; P < 0.0001.

Mentions: There were large between-strain differences in density (Fig 5A–5C). For example, in somatic tissues the Wolbachia copy number varies over a 19-fold range. Furthermore, the strains have different tissue tropisms, with a significant strain-by-tissue interaction (Fig 5A–5C). The density in the testes and head + thorax tended to be tightly correlated (Pearson’s correlation test: r = 0.89; P < 0.0001), and frequently differed from the density in eggs (Pearson’s correlation test: head + thorax–eggs: r = 0.63; P = 0.01; testes–eggs: r = 0.61; P = 0.013).


Should Symbionts Be Nice or Selfish? Antiviral Effects of Wolbachia Are Costly but Reproductive Parasitism Is Not.

Martinez J, Ok S, Smith S, Snoeck K, Day JP, Jiggins FM - PLoS Pathog. (2015)

Wolbachia tissue tropism.Mean Wolbachia density in (A) head and thorax of females, (B) testes and (C) freshly laid eggs. Error bars are standard errors. Letters indicate significant differences based on a Tukey’s honest significance test on ln-transformed data. All tissues were analyzed in a single linear model to test for difference in tissue tropism: strain effect: F15,427 = 131. 1; P < 0.0001; tissue effect: F2,427 = 4448. 8; P < 0.0001; strain × tissue effect: F30,427 = 11.5; P < 0.0001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4488530&req=5

ppat.1005021.g005: Wolbachia tissue tropism.Mean Wolbachia density in (A) head and thorax of females, (B) testes and (C) freshly laid eggs. Error bars are standard errors. Letters indicate significant differences based on a Tukey’s honest significance test on ln-transformed data. All tissues were analyzed in a single linear model to test for difference in tissue tropism: strain effect: F15,427 = 131. 1; P < 0.0001; tissue effect: F2,427 = 4448. 8; P < 0.0001; strain × tissue effect: F30,427 = 11.5; P < 0.0001.
Mentions: There were large between-strain differences in density (Fig 5A–5C). For example, in somatic tissues the Wolbachia copy number varies over a 19-fold range. Furthermore, the strains have different tissue tropisms, with a significant strain-by-tissue interaction (Fig 5A–5C). The density in the testes and head + thorax tended to be tightly correlated (Pearson’s correlation test: r = 0.89; P < 0.0001), and frequently differed from the density in eggs (Pearson’s correlation test: head + thorax–eggs: r = 0.63; P = 0.01; testes–eggs: r = 0.61; P = 0.013).

Bottom Line: Symbionts can have mutualistic effects that increase their host's fitness and/or parasitic effects that reduce it.Strong antiviral protection is associated with substantial reductions in other fitness-related traits, whereas no such trade-off was detected for cytoplasmic incompatibility.The reason for this difference is likely that antiviral protection requires high symbiont densities but cytoplasmic incompatibility does not.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, University of Cambridge, Cambridge, United Kingdom.

ABSTRACT
Symbionts can have mutualistic effects that increase their host's fitness and/or parasitic effects that reduce it. Which of these strategies evolves depends in part on the balance of their costs and benefits to the symbiont. We have examined these questions in Wolbachia, a vertically transmitted endosymbiont of insects that can provide protection against viral infection and/or parasitically manipulate its hosts' reproduction. Across multiple symbiont strains we find that the parasitic phenotype of cytoplasmic incompatibility and antiviral protection are uncorrelated. Strong antiviral protection is associated with substantial reductions in other fitness-related traits, whereas no such trade-off was detected for cytoplasmic incompatibility. The reason for this difference is likely that antiviral protection requires high symbiont densities but cytoplasmic incompatibility does not. These results are important for the use of Wolbachia to block dengue virus transmission by mosquitoes, as natural selection to reduce these costs may lead to reduced symbiont density and the loss of antiviral protection.

No MeSH data available.


Related in: MedlinePlus