Werren John H, Loehlin David W
Department of Biology, University of Rochester, Rochester, NY 14627, USA.
Cold Spring Harb Protoc. 2009 Oct;2009(10):pdb.prot5312. doi: 10.1101/pdb.prot5312.
Nasonia is a complex of four closely related species of wasps with several features that make it an excellent system for a variety of genetic studies. These include a short generation time, ease of rearing, interfertile species, visible and molecular markers, and a sequenced genome. However, the Nasonia species normally are completely or partially reproductively isolated owing to Wolbachia, widespread intracellular bacteria found in arthropods and nematodes. Wolbachia cause cytoplasmic incompatibility (CI) in Nasonia. Although the current genome-sequenced strains of Nasonia (AsymCX, IV7[u], RV2X[u]) are all Wolbachia-free, crosses between infected and uninfected wasps, or between infected wasps of different species, will fail because of Wolbachia. The sperm modification that induces CI appears to be established before the adult stage, so it is generally not possible to cure an infection and break the CI barrier in the same generation. However, a Wolbachia infection can be removed from a strain over a number of generations by feeding antibiotics and selecting on females showing partial CI. This protocol describes the methods to cure a Nasonia strain of its Wolbachia symbionts.
丽蝇蛹集金小蜂是一个由四种亲缘关系密切的黄蜂物种组成的复合体,具有多种特性,使其成为进行各种遗传学研究的理想系统。这些特性包括世代周期短、易于饲养、物种间可育、具有可见和分子标记以及已测序的基因组。然而,丽蝇蛹集金小蜂物种通常由于沃尔巴克氏体而完全或部分生殖隔离,沃尔巴克氏体是在节肢动物和线虫中广泛存在的细胞内细菌。沃尔巴克氏体在丽蝇蛹集金小蜂中会引起细胞质不亲和(CI)。尽管目前已进行基因组测序的丽蝇蛹集金小蜂菌株(AsymCX、IV7[u]、RV2X[u])均无沃尔巴克氏体,但感染的和未感染的黄蜂之间,或不同物种的感染黄蜂之间的杂交都会因沃尔巴克氏体而失败。诱导细胞质不亲和的精子修饰似乎在成虫阶段之前就已形成,所以通常不可能在同一代治愈感染并打破细胞质不亲和障碍。然而,通过喂食抗生素并选择表现出部分细胞质不亲和的雌性,可以在几代的时间内从一个菌株中消除沃尔巴克氏体感染。本方案描述了治愈丽蝇蛹集金小蜂菌株中沃尔巴克氏体共生菌的方法。