Université de Poitiers, UMR CNRS 7267 Ecologie et Biologie des Interactions, Equipe Ecologie Evolution Symbiose, Poitiers, France.
PLoS One. 2013 Dec 6;8(12):e82633. doi: 10.1371/journal.pone.0082633. eCollection 2013.
Maternally inherited Wolbachia (α-Proteobacteria) are widespread parasitic reproductive manipulators. A growing number of studies have described the presence of different Wolbachia strains within a same host. To date, no naturally occurring multiple infections have been recorded in terrestrial isopods. This is true for Armadillidium vulgare which is known to harbor non simultaneously three Wolbachia strains. Traditionally, such Wolbachia are detected by PCR amplification of the wsp gene and strains are characterized by sequencing. The presence of nucleotide deletions or insertions within the wsp gene, among these three different strains, provides the opportunity to test a novel genotyping method. Herein, we designed a new primer pair able to amplify products whose lengths are specific to each Wolbachia strain so as to detect the presence of multi-infections in A. vulgare. Experimental injections of Wolbachia strains in Wolbachia-free females were used to validate the methodology. We re-investigated, using this novel method, the infection status of 40 females sampled in 2003 and previously described as mono-infected based on the classical sequencing method. Among these females, 29 were identified as bi-infected. It is the first time that naturally occurring multiple infections of Wolbachia are detected within an individual A. vulgare host. Additionally, we resampled 6 of these populations in 2010 to check the infection status of females.
母体遗传的沃尔巴克氏体（α-变形菌）是广泛存在的寄生性生殖操纵者。越来越多的研究描述了同一宿主内存在不同的沃尔巴克氏体菌株。迄今为止，在陆生等足目动物中尚未记录到自然发生的多重感染。这在俗称“潮虫”的普通卷甲虫（Armadillidium vulgare）中是真实的，已知其同时携带三种沃尔巴克氏体菌株。传统上，通过 wsp 基因的 PCR 扩增来检测此类沃尔巴克氏体，并用测序来鉴定菌株。在这三种不同菌株的 wsp 基因中存在核苷酸缺失或插入，为测试新的基因分型方法提供了机会。在此，我们设计了一对新的引物，可以扩增出特定于每种沃尔巴克氏体菌株的产物，从而检测普通卷甲虫中的多重感染。使用沃尔巴克氏体菌株的实验注射来验证这种方法。我们使用这种新方法重新研究了 2003 年采集的 40 只雌性个体的感染状态，这些雌性个体之前基于经典测序方法被描述为单感染。其中 29 只被鉴定为双感染。这是首次在单个普通卷甲虫宿主中检测到自然发生的沃尔巴克氏体多重感染。此外，我们在 2010 年重新对其中的 6 个种群进行了采样，以检查雌性个体的感染状态。
