Singh Kumar Saurabh, Troczka Bartlomiej J, Duarte Ana, Balabanidou Vasileia, Trissi Nasser, Carabajal Paladino Leonela Z, Nguyen Petr, Zimmer Christoph T, Papapostolou Kyriaki M, Randall Emma, Lueke Bettina, Marec Frantisek, Mazzoni Emanuele, Williamson Martin S, Hayward Alex, Nauen Ralf, Vontas John, Bass Chris
College of Life and Environmental Sciences, Biosciences, University of Exeter, Penryn Campus, Penryn, Cornwall, UK.
Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, Crete, Greece.
Sci Adv. 2020 May 6;6(19):eaba1070. doi: 10.1126/sciadv.aba1070. eCollection 2020 May.
Host shifts can lead to ecological speciation and the emergence of new pests and pathogens. However, the mutational events that facilitate the exploitation of novel hosts are poorly understood. Here, we characterize an adaptive walk underpinning the host shift of the aphid to tobacco, including evolution of mechanisms that overcame tobacco chemical defenses. A series of mutational events added as many as 1.5 million nucleotides to the genome of the tobacco-adapted subspecies, , and yielded profound increases in expression of an enzyme that efficiently detoxifies nicotine, both in aphid gut tissue and in the bacteriocytes housing the obligate aphid symbiont . This dual evolutionary solution overcame the challenge of preserving fitness of a mutualistic symbiosis during adaptation to a toxic novel host. Our results reveal the intricate processes by which genetic novelty can arise and drive the evolution of key innovations required for ecological adaptation.
宿主转移可导致生态物种形成以及新害虫和病原体的出现。然而，促进对新宿主利用的突变事件却鲜为人知。在此，我们描述了支撑蚜虫向烟草宿主转移的适应性进化历程，包括克服烟草化学防御机制的进化。一系列突变事件使适应烟草的亚种基因组增加了多达150万个核苷酸，并使一种能有效解毒尼古丁的酶在蚜虫肠道组织和容纳专性蚜虫共生菌的含菌细胞中的表达大幅增加。这种双重进化解决方案克服了在适应有毒新宿主过程中维持互利共生适应性的挑战。我们的研究结果揭示了遗传新奇性产生并推动生态适应所需关键创新进化的复杂过程。
