WMel Wolbachia genome remains stable after 7 years in Australian Aedes aegypti field populations.

Kimberley R Dainty,Heather A Flores,Daniela S Gonçalves,Silk Yu Lin,Jane Hawkey,Etiene C Pacidônio,Johanna M Duyvestyn,Cameron P Simmons,Kathryn E Holt,Scott L O'Neill,Louise M Judd,Tanya B O'Donnell

doi:10.1099/mgen.0.000641

Abstract

Infection of wMel Wolbachia in Aedes aegypti imparts two signature features that enable its application for biocontrol of dengue. First, the susceptibility of mosquitoes to viruses such as dengue and Zika is reduced. Second, a reproductive manipulation is caused that enables wMel introgression into wild-type mosquito populations. The long-term success of this method relies, in part, on evolution of the wMel genome not compromising the critical features that make it an attractive biocontrol tool. This study compared the wMel Wolbachia genome at the time of initial releases and 1–7 years post-release in Cairns, Australia. Our results show the wMel genome remains highly conserved up to 7 years post-release in gene sequence, content, synteny and structure. This work suggests the wMel genome is stable in its new mosquito host and, therefore, provides reassurance on the potential for wMel to deliver long-term public-health impacts.

Highlights

Dengue is the fastest growing mosquito-b orne disease, having increased in incidence by 30-fold over the past 50 years [1]
Through a combination of short- and long-read sequencing, we show that the wMel genome has remained highly stable despite multiple host transfers, and 7 years post-release in wMel-infected mosquitoes in the field
Analysis of wMel Wolbachia genomes collected from Gordonvale ascertained the presence of two SNPs, compared to the previously described reference genome of wMel (Fig. 3, Table 1)

Summary

Introduction

Dengue is the fastest growing mosquito-b orne disease, having increased in incidence by 30-fold over the past 50 years [1]. Many Wolbachia strains induce a reproductive manipulation called cytoplasmic incompatibility (CI). This provides a fitness advantage to Wolbachia-infected females, helping to drive Wolbachia into wild-type populations [8, 9]. The World Mosquito Program (WMP) transinfected a strain of Wolbachia native to Drosophila melanogaster, wMel, into Aedes aegypti. This infection causes the two desired features, CI [13, 14] and inhibition of arbovirus transmission [13, 15,16,17,18,19,20,21,22], which underpin the biocontrol method

Objectives

Methods

Results

Conclusion