节肢动物的母体遗传内共生体是最丰富和多样化的细菌之一。这些细菌内共生体还显示出广泛的水平转移到分类学上不相关的宿主,并在其基因组中广泛重组。当不同的节肢动物宿主像在生态群落中接触时,可以增强这种水平转移。更高的水平转移速率也可以增加内共生体之间的重组概率,因为它们现在共享相同的宿主细胞质。然而,由于大多数研究选择很少的宿主分类单元和宿主之间特定的生态相互作用,因此很少有关于社区内共生体数据的报告。为了更好地了解宿主种群内共生体的传播,我们调查了发病率,多样性,水平转移的程度,和三个内共生体的重组(Wolbachia,Cardinium,和Arsenophonus)在特定的土壤节肢动物群落中。Wolbachia菌株的特征在于MLST基因,而16SrRNA基因用于Cardinium和Arsenophonus。在3,509个个体寄主节肢动物中,属于390种形态物种,12.05%感染Wolbachia,2.82%含钆,2.05%含砷。宿主与内共生体之间的系统发育不一致表明内共生体在该群落中广泛的水平转移。还发现了3例Wolbachia超群之间的重组和8例超群内重组。相似性的统计测试表明,超组AWolbachia和Cardinium显示出与群落内广泛的水平转移一致的模式,但对于超组BWolbachia和Arsenophonus则不一致。我们强调了广泛的社区范围研究的重要性,以更好地了解内共生生物在全球节肢动物社区中的传播。
Maternally inherited endosymbionts of arthropods are one of the most abundant and diverse group of bacteria. These bacterial endosymbionts also show extensive horizontal transfer to taxonomically unrelated hosts and widespread
recombination in their genomes. Such horizontal transfers can be enhanced when different arthropod hosts come in contact like in an ecological community. Higher rates of horizontal transfer can also increase the probability of
recombination between endosymbionts, as they now share the same host cytoplasm. However,
reports of community-wide endosymbiont data are rare as most studies choose few host taxa and specific ecological interactions among the hosts. To better understand endosymbiont spread within host populations, we investigated the incidence, diversity, extent of horizontal transfer, and recombination of three endosymbionts (Wolbachia, Cardinium, and Arsenophonus) in a specific soil arthropod community. Wolbachia strains were characterized with MLST genes whereas 16S rRNA gene was used for Cardinium and Arsenophonus. Among 3,509 individual host arthropods, belonging to 390 morphospecies, 12.05% were infected with Wolbachia, 2.82% with Cardinium and 2.05% with Arsenophonus. Phylogenetic incongruence between host and endosymbiont indicated extensive horizontal transfer of endosymbionts within this community. Three cases of
recombination between Wolbachia supergroups and eight incidences of within-supergroup
recombination were also found. Statistical tests of similarity indicated supergroup A Wolbachia and Cardinium show a pattern consistent with extensive horizontal transfer within the community but not for supergroup B Wolbachia and Arsenophonus. We highlight the importance of extensive community-wide studies for a better understanding of the spread of endosymbionts across global arthropod communities.