The hitchhiker's guide to Europe: the infection dynamics of an ongoing Wolbachia invasion and mitochondrial selective sweep in Rhagoletis cerasi

Wolbachia is a maternally inherited and ubiquitous endosymbiont of insects. It can hijack host reproduction by manipulations such as cytoplasmic incompatibility (CI) to enhance vertical transmission. Horizontal transmission of Wolbachia can also result in the colonization of new mitochondrial lineages. In this study, we present a 15-year-long survey of Wolbachia in the cherry fruit fly Rhagoletis cerasi across Europe and the spatiotemporal distribution of two prevalent strains, wCer1 and wCer2, and associated mitochondrial haplotypes in Germany. Across most of Europe, populations consisted of either 100% singly (wCer1) infected individuals with haplotype HT1, or 100% doubly (wCer1&2) infected individuals with haplotype HT2, differentiated only by a single nucleotide polymorphism. In central Germany, singly infected populations were surrounded by transitional populations, consisting of both singly and doubly infected individuals, sandwiched between populations fixed for wCer1&2. ...

沃尔巴克氏体（Wolbachia）是一类母系遗传且广泛分布于昆虫体内的内共生菌。它可通过诸如细胞质不相容（cytoplasmic incompatibility, CI）这类操作手段操纵宿主生殖，以提升自身的垂直传播效率。沃尔巴克氏体的水平传播还可促成新的线粒体谱系的定殖。本研究针对欧洲范围内的樱桃实蝇（Rhagoletis cerasi）体内的沃尔巴克氏体开展了为期15年的调查，并分析了德国境内两种优势菌株wCer1、wCer2的时空分布特征，以及与之关联的线粒体单倍型。在欧洲大部分区域，果蝇种群要么是100%单一感染wCer1且携带单倍型HT1的个体，要么是100%同时感染wCer1与wCer2且携带单倍型HT2的个体，二者仅通过一个单核苷酸多态性加以区分。在德国中部地区，单一感染种群被过渡型种群环绕，后者同时包含单一感染与双重感染的个体，且夹在固定感染wCer1与wCer2的种群之间。……