Pest and Environmental Adaptation Research Group, Bio21 Institute and the School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.
PLoS Negl Trop Dis. 2020 Apr 3;14(4):e0008204. doi: 10.1371/journal.pntd.0008204. eCollection 2020 Apr.
Wolbachia are being used to reduce dengue transmission by Aedes aegypti mosquitoes around the world. To date releases have mostly involved Wolbachia strains with limited fitness effects but strains with larger fitness costs could be used to suppress mosquito populations. However, such infections are expected to evolve towards decreased deleterious effects. Here we investigate potential evolutionary changes in the wMelPop infection transferred from Drosophila melanogaster to Aedes aegypti more than ten years (~120 generations) ago. We show that most deleterious effects of this infection have persisted despite strong selection to ameliorate them. The wMelPop-PGYP infection is difficult to maintain in laboratory colonies, likely due to the persistent deleterious effects coupled with occasional maternal transmission leakage. Furthermore, female mosquitoes can be scored incorrectly as infected due to transmission of Wolbachia through mating. Infection loss in colonies was not associated with evolutionary changes in the nuclear background. These findings suggest that Wolbachia transinfections with deleterious effects may have stable phenotypes which could ensure their long-term effectiveness if released in natural populations to reduce population size.
沃尔巴克氏体被用于减少世界各地埃及伊蚊传播登革热。迄今为止，释放的大多是具有有限适应度影响的沃尔巴克氏体菌株，但具有更大适应度成本的菌株可用于抑制蚊群。然而，预计此类感染会朝着降低有害影响的方向进化。在这里，我们研究了十多年（~120 代）前从黑腹果蝇转移到埃及伊蚊的 wMelPop 感染的潜在进化变化。我们表明，尽管有强烈的选择来减轻这些感染的有害影响，但大多数有害影响仍然持续存在。wMelPop-PGYP 感染在实验室群体中难以维持，这可能是由于持续的有害影响，加上偶尔的母系传播泄漏。此外，由于沃尔巴克氏体通过交配传播，雌性蚊子可能会被错误地标记为感染。感染损失与核背景的进化变化无关。这些发现表明，具有有害影响的沃尔巴克氏体转染可能具有稳定的表型，如果在自然种群中释放以减少种群数量，它们可能会确保其长期有效性。
