Data from: Multiple endosymbiont infections and reproductive manipulations in a linyphiid spider population

In many arthropods, maternally inherited endosymbiotic bacteria can increase infection frequency by manipulating host reproduction. Multiple infections of different bacteria in a single host population are common, yet few studies have documented concurrent endosymbiont phenotypes or explored their potential interactions. We hypothesized that spiders might be a particularly useful taxon for investigating endosymbiont interactions, because they are host to a plethora of endosymbiotic bacteria and frequently exhibit multiple infections. We established two matrilines from the same population of the linyphiid spider Mermessus fradeorum and then used antibiotic curing and controlled mating assays to demonstrate that each matriline was subject to a distinct endosymbiotic reproductive manipulation. One matriline was co-infected with Rickettsia and Wolbachia and produced offspring with a radical female bias. Antibiotic treatment eliminated both endosymbionts and restored an even sex ratio to subsequent generations. Chromosomal and fecundity observations suggest a feminization mechanism. In the other matriline, a separate factorial mating assay of cured and infected spiders demonstrated strong cytoplasmic incompatibility (CI) induced by a different strain of Wolbachia. However, males with this Wolbachia induced only mild CI when mated with the Rickettsia–Wolbachia females. In a subsequent survey of a field population of M. fradeorum, we detected these same three endosymbionts infecting 55% of the spiders in almost all possible combinations, with nearly half of the infected spiders exhibiting multiple infection. Our results suggest that a dynamic network of endosymbionts may interact both within multiply infected hosts and within a population subject to multiple strong reproductive manipulations.在众多节肢动物（arthropods）中，母系遗传的内共生细菌可通过操纵宿主繁殖来提升自身感染频率。单一宿主种群内同时感染多种不同细菌的现象十分普遍，但鲜有研究同时记录内共生体的表型，或探究它们之间潜在的相互作用。我们提出假说：蜘蛛或许是研究内共生体相互作用的理想类群，因为它们宿主了大量内共生细菌，且常出现多重感染。 我们从同一皿蛛科（Linyphiidae）蜘蛛莫氏蛛（Mermessus fradeorum）种群中建立了两个母系谱系，随后通过抗生素清除法与控制性交配实验，证实每个母系谱系均受到独特的内共生体繁殖操纵。其中一个母系谱系同时感染了立克次体（Rickettsia）与沃尔巴克氏体（Wolbachia），其后代呈现显著的雌性偏倚。抗生素处理可清除这两种内共生细菌，并使后代恢复至均等的性比。染色体观测与繁殖力数据提示，该操纵的机制为雌性化作用。 在另一个母系谱系中，针对清除感染与未清除感染的蜘蛛开展的析因交配实验显示，另一种沃尔巴克氏体（Wolbachia）菌株可诱导强烈的细胞质不相容性（cytoplasmic incompatibility，CI）。然而，当携带该沃尔巴克氏体的雄蛛与感染立克次体-沃尔巴克氏体的雌蛛交配时，仅会引发轻度的细胞质不相容性。 后续对莫氏蛛（Mermessus fradeorum）野外种群的调查显示，我们检测到了上述三种内共生细菌，它们在55%的蜘蛛个体中存在感染，且几乎涵盖所有可能的组合形式，近半数受感染蜘蛛呈现多重感染状态。 我们的研究结果表明，内共生体之间可能形成动态互作网络，这种互作既发生在多重感染的宿主体内，也存在于受到多种强繁殖操纵的种群中。