French invasive Asian tiger mosquito populations harbor reduced bacterial microbiota and genetic diversity compared to Vietnamese autochthonous relatives.

G Minard,F H Tran,C Valiente Moro,Van Tran Van,P Mavingui,C Bellet,G Lambert,Trang Huynh Thi Thuy,Khanh Ly Huynh Kim,C Goubert

doi:10.3389/fmicb.2015.00970

Abstract

The Asian tiger mosquito Aedes albopictus is one of the most significant pathogen vectors of the twenty-first century. Originating from Asia, it has invaded a wide range of eco-climatic regions worldwide. The insect-associated microbiota is now recognized to play a significant role in host biology. While genetic diversity bottlenecks are known to result from biological invasions, the resulting shifts in host-associated microbiota diversity has not been thoroughly investigated. To address this subject, we compared four autochthonous Ae. albopictus populations in Vietnam, the native area of Ae. albopictus, and three populations recently introduced to Metropolitan France, with the aim of documenting whether these populations display differences in host genotype and bacterial microbiota. Population-level genetic diversity (microsatellite markers and COI haplotype) and bacterial diversity (16S rDNA metabarcoding) were compared between field-caught mosquitoes. Bacterial microbiota from the whole insect bodies were largely dominated by Wolbachia pipientis. Targeted analysis of the gut microbiota revealed a greater bacterial diversity in which a fraction was common between French and Vietnamese populations. The genus Dysgonomonas was the most prevalent and abundant across all studied populations. Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam. These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects.

Highlights

Mosquitoes are considered by the World Health Organization to be the most medically important disease vectors
Mosquito sampling in Vietnam was performed during October 2012 at Hô Chí Minh City (HCM), Bình Du’o’ng (BD), Vung Tàu City (VT), and Bù Gia Mâp (BGM) (Figure 1)
We demonstrated that Wolbachia is the predominant bacterial species in Ae. albopictus from Madagascar when using whole body genomic DNA, constituting up to 99% of high throughput sequences recovered (Minard et al, 2014)

Summary

Introduction

Mosquitoes are considered by the World Health Organization to be the most medically important disease vectors. Ae. albopictus is considered as one of the most geographically invasive species. It has rapidly spread from its native area of South and East Asia to reach various eco-climatic regions in America, Africa, Oceania and Europe (Bonizzoni et al, 2013). The intrinsic capacities of the mosquito populations largely play an important role in their ecological plasticity. This assumption remains surprising as according to the “paradox of invasion,” recent introductions often imply a burden for the genetic structure of newly introduced populations (reviewed by Handley et al, 2011)

Objectives

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Results