Department of Entomology, University of Kentucky, Lexington, KY 40546, USA.
Appl Environ Microbiol. 2010 Sep;76(17):5887-91. doi: 10.1128/AEM.00218-10. Epub 2010 Jul 2.
Obligately intracellular Wolbachia bacteria infect numerous invertebrates and often manipulate host reproduction to facilitate the spread of infection. An example of reproductive manipulation is Wolbachia-induced cytoplasmic incompatibility (CI), which occurs commonly in insects. This CI has been the focus both of basic scientific studies of naturally occurring invasion events and of applied investigations on the use of Wolbachia as a vehicle to drive desired genotypes into insect populations ("gene drive" or "population replacement" strategies). The latter application requires an ability to generate artificial infections that cause a pattern of unidirectional incompatibility with the targeted host population. A suggested target of population replacement strategies is the mosquito Aedes albopictus (Asian tiger mosquito), an important invasive pest and disease vector. Aedes albopictus individuals are naturally "superinfected" with two Wolbachia types: wAlbA and wAlbB. Thus, generating a strain that is unidirectionally incompatible with field populations requires the introduction of an additional infection into the preexisting superinfection. Although prior reports demonstrate an ability to transfer Wolbachia infections to A. albopictus artificially, including both intra- and interspecific Wolbachia transfers, previous efforts have not generated a strain capable of invading natural populations. Here we describe the generation of a stable triple infection by introducing Wolbachia wRi from Drosophila simulans into a naturally superinfected A. albopictus strain. The triple-infected strain displays a pattern of unidirectional incompatibility with the naturally infected strain. This unidirectional CI, combined with a high fidelity of maternal inheritance and low fecundity effects, suggests that the artificial cytotype could serve as an appropriate vehicle for gene drive.
专性细胞内共生的沃尔巴克氏体（Wolbachia）细菌感染了许多无脊椎动物，并经常操纵宿主繁殖以促进感染的传播。生殖操纵的一个例子是沃尔巴克氏体诱导的细胞质不亲和性（CI），它在昆虫中很常见。这种 CI 既是自然发生的入侵事件的基础科学研究的重点，也是利用沃尔巴克氏体作为载体将所需基因型驱动到昆虫种群中的应用研究的重点（“基因驱动”或“种群替代”策略）。后者的应用需要能够产生导致与目标宿主种群单向不亲和的人工感染。种群替代策略的一个建议目标是蚊子 Aedes albopictus（亚洲虎蚊），这是一种重要的入侵害虫和疾病媒介。Aedes albopictus 个体自然“超级感染”有两种沃尔巴克氏体类型：wAlbA 和 wAlbB。因此，生成与野外种群单向不亲和的菌株需要将额外的感染引入预先存在的超级感染中。尽管先前的报告表明有能力将沃尔巴克氏体感染人工转移到 A. albopictus 中，包括种内和种间的沃尔巴克氏体转移，但以前的努力并没有产生能够入侵自然种群的菌株。在这里，我们描述了通过将来自 Drosophila simulans 的沃尔巴克氏体 wRi 引入自然超级感染的 A. albopictus 菌株中来产生稳定的三重感染。三重感染的菌株显示出与自然感染菌株单向不亲和的模式。这种单向 CI ，加上高保真的母系遗传和低生育力效应，表明人工细胞型可以作为基因驱动的合适载体。
