First detection of Wolbachia in the New Zealand biota.

Benjamin Bridgeman,Mary Morgan-Richards,Steven A Trewick,David Wheeler,Luciano Andrade Moreira

doi:10.1371/journal.pone.0195517

Abstract

Wolbachia is one of the most widespread intracellular bacteria on earth, estimated to infect between 40 and 66% of arthropod species in most ecosystems that have been surveyed. Their significance rests not only in their vast distribution, but also in their ability to modify the reproductive biology of their hosts, which can ultimately affect genetic diversity and speciation of infected populations. Wolbachia has yet to be formally identified in the fauna of New Zealand which has high levels of endemic biodiversity and this represents a gap in our understanding of the global biology of Wolbachia. Using High Throughput Sequencing (HTS) of host DNA in conjunction with traditional molecular techniques we identified six endemic Orthoptera species that were positive for Wolbachia infection. In addition, short-sequence amplification with Wolbachia specific primers applied to New Zealand and introduced invertebrates detected a further 153 individuals positive for Wolbachia. From these short-range DNA amplification products sequence data was obtained for the ftsZ gene region from 86 individuals representing 10 host species. Phylogenetic analysis using the sequences obtained in this study reveals that there are two distinct Wolbachia bacteria lineages in New Zealand hosts belonging to recognised Wolbachia supergroups (A and B). These represent the first described instances of Wolbachia in the New Zealand native fauna, including detection in putative parasitoids of infected Orthoptera suggesting a possible transmission path. Our detection of Wolbachia infections of New Zealand species provides the opportunity to study local transmission of Wolbachia and explore their role in the evolution of New Zealand invertebrates.

Highlights

The bacterium Wolbachia [1,2] is estimated to infect between 40 and 66% of arthropod species worldwide [3,4,5] making it among the most abundant intracellular bacterial genera
We found similar high levels of Wolbachia DNA sequence in a cave weta (Macropathus sp.) and a ground weta (Hemiandrus brucei)
To ascertain the level of genome coverage represented by Wolbachia reads in these two species, the short reads were mapped to the complete genome of the Wolbachia endosymbiont of Drosophila melanogaster. This revealed that the Macropathus sp. reads covered 30% of this reference genome, whilst the reads from Hemiandrus brucei mapped over 33.6% of the Wolbachia reference

Summary

Introduction

The bacterium Wolbachia [1,2] is estimated to infect between 40 and 66% of arthropod species worldwide [3,4,5] making it among the most abundant intracellular bacterial genera. Wolbachia is a maternally inherited endosymbiont that can induce a range of host phenotypic responses, including cytoplasmic incompatibility, male death, feminization, and parthenogenesis [6,7,8,9,10]. Wolbachia infections can have long-term evolutionary effects on their host lineages, in addition to immediate reproductive modifications, by providing pathways to rapid reproductive isolation and influencing the evolution of sex-determining mechanisms [6,7,9,10,11]. Wolbachia is being trialled as a biocontrol agent of invasive and disease transmiting insects including medflies [12] and mosquitos as part of the Eliminate Dengue Program [13,14,15]. As Wolbachia can become an obligate parasite of parasitic worms it is the target of research into antimicrobial drugs by the Anti-Wolbachia Consortium, with the goal of preventing the growth and reproduction of the worms and preventing the diseases they induce [16,17]

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Results

Conclusion