Population dynamics and rapid spread of Cardinium, a bacterial endosymbiont causing cytoplasmic incompatibility in Encarsia pergandiella (Hymenoptera: Aphelinidae)

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.

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Cytoplasmic incompatibility between Old and New World populations of a tramp ant

10.1101/2020.03.13.988675 ◽

2020 ◽

Author(s):

Çiğdem Ün ◽

Eva Schultner ◽

Alejandro Manzano-Marín ◽

Laura V. Flórez ◽

Bernhard Seifert ◽

...

Keyword(s):

Reproductive Isolation ◽

New World ◽

Evolutionary Dynamics ◽

Cytoplasmic Incompatibility ◽

Isolated Populations ◽

First Case ◽

Rapid Spread ◽

Tramp Ant ◽

Globally Distributed ◽

Geographically Isolated

AbstractAs we enter the Anthropocene, the evolutionary dynamics of species will change drastically, and as yet unpredictably, due to human activity. Already today, increases in global human traffic have resulted in the rapid spread of species to new areas, leading to the formation of geographically isolated populations. These go on to evolve in allopatry, which can lead to reproductive isolation, and potentially, the formation of new species. Surprisingly, little is known about such eco-evolutionary processes in ants, even though numerous invasive ant species are globally distributed in geographically isolated populations. Here, we describe the first case of cytoplasmic incompatibility (CI) between populations of a cosmotropic distributed tramp ant with Asian roots, Cardiocondyla obscurior, which has acquired a novel Wolbachia strain in the New World. Our study uncovers the first symbiont-induced mechanism of reproductive isolation in ants, providing a novel perspective on the biology of globally distributed ants.

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Population Dynamics of the Wolbachia Infection Causing Cytoplasmic Incompatibility in Drosophila melanogaster

Genetics ◽

10.1093/genetics/148.1.221 ◽

1998 ◽

Vol 148 (1) ◽

pp. 221-231 ◽

Cited By ~ 10

Author(s):

Ary A Hoffmann ◽

Miriam Hercus ◽

Hayat Dagher

Keyword(s):

Population Dynamics ◽

Drosophila Melanogaster ◽

Cytoplasmic Incompatibility ◽

Larval Density ◽

Natural Populations ◽

Wolbachia Infection ◽

Field Conditions ◽

Exact Nature ◽

Infection Status ◽

Factors Influencing

Abstract Field populations of Drosophila melanogaster are often infected with Wolbachia, a vertically transmitted microorganism. Under laboratory conditions the infection causes partial incompatibility in crosses between infected males and uninfected females. Here we examine factors influencing the distribution of the infection in natural populations. We show that the level of incompatibility under field conditions was much weaker than in the laboratory. The infection was not transmitted with complete fidelity under field conditions, while field males did not transmit the infection to uninfected females and Wolbachia did not influence sperm competition. There was no association between field fitness as measured by fluctuating asymmetry and the infection status of adults. Infected field females were smaller than uninfecteds in some collections from a subtropical location, but not in other collections from the same location. Laboratory cage studies showed that the infection did not change in frequency when populations were maintained at a low larval density, but it decreased in frequency at a high larval density. Monitoring of infection frequencies in natural populations indicated stable frequencies in some populations but marked fluctuations in others. Simple models suggest that the infection probably provides a fitness benefit for the host in order to persist in populations. The exact nature of this benefit remains elusive.

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Evolutionary genetics of cytoplasmic incompatibility genes cifA and cifB in prophage WO of Wolbachia

10.1101/180075 ◽

2017 ◽

Cited By ~ 1

Author(s):

Amelia R. I. Lindsey ◽

Danny W. Rice ◽

Sarah R. Bordenstein ◽

Andrew W. Brooks ◽

Seth R. Bordenstein ◽

...

Keyword(s):

Amino Acid ◽

Cytoplasmic Incompatibility ◽

Evolutionary Genetics ◽

Amino Acid Sequences ◽

Embryonic Mortality ◽

Functional Annotations ◽

Bacterial Endosymbiont ◽

Reproductive Parasitism ◽

Host Development

AbstractThe bacterial endosymbiont Wolbachia manipulates arthropod reproduction to facilitate its maternal spread through populations. The most common manipulation is cytoplasmic incompatibility (CI): Wolbachia-infected males produce modified sperm that cause embryonic mortality, unless rescued by eggs harboring the same Wolbachia. The genes underlying CI, cifA and cifB, were recently identified in the eukaryotic association module of Wolbachia’s prophage WO. Here, we use transcriptomic and genomic approaches to address three important evolutionary facets of these genes. First, we assess whether or not cifA and cifB comprise a classic toxin-antitoxin operon, and show they do not form an operon in strain wMel. They coevolve but exhibit strikingly distinct expression across host development. Second, we provide new domain and functional predictions across homologs within Wolbachia, and we show amino acid sequences vary substantially across the genus. Lastly, we investigate conservation of cifA and cifB and find degradation and loss of the genes is common in strains that no longer induce CI. Taken together, we find no evidence for the operon hypothesis in wMel, provide functional annotations that broaden the potential mechanisms of CI induction, illuminate recurrent erosion of cifA and cifB in non-CI strains, and advance an understanding of the most widespread form of reproductive parasitism.

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