Data from: Bacterial endosymbiont infections in ‘living fossils’: a case study of North American vaejovid scorpions

Bacterial endosymbionts are common among arthropods, and maternally inherited forms can affect the reproductive and behavioural traits of their arthropod hosts. The prevalence of bacterial endosymbionts and their role in scorpion evolution have rarely been investigated. In this study, 61 samples from 40 species of scorpion in the family Vaejovidae were screened for the presence of the bacterial endosymbionts Cardinium, Rickettsia, Spiroplasma and Wolbachia. No samples were infected by these bacteria. However, one primer pair specifically designed to amplify Rickettsia amplified nontarget genes of other taxa. Similar off-target amplification using another endosymbiont-specific primer was also found during preliminary screenings. Results caution against the overreliance on previously published screening primers to detect bacterial endosymbionts in host taxa and suggest that primer specificity may be higher in primers targeting nuclear rather than mitochondrial genes.

细菌内共生体（bacterial endosymbionts）在节肢动物中分布广泛，其中母系遗传的类群可影响其节肢动物宿主的生殖与行为性状。目前针对细菌内共生体的流行率及其在蝎子演化过程中所发挥的作用的相关研究较为匮乏。本研究针对来自瓮蝎科（Vaejovidae）40个物种的61份蝎子样本，开展了针对卡迪纳菌属（Cardinium）、立克次体属（Rickettsia）、螺原体属（Spiroplasma）以及沃尔巴克氏体属（Wolbachia）这四类细菌内共生体的筛查。结果未检测到任何样本被上述四类细菌感染。然而，其中一对专门用于扩增立克次体属的引物，却扩增出了其他分类群的非靶标基因；在初步筛查阶段，使用另一株内共生体特异性引物时也观察到了类似的非靶标扩增现象。本研究结果警示，不应过度依赖已发表的筛查引物来检测宿主类群中的细菌内共生体，同时表明靶向核基因的引物或许比靶向线粒体基因的引物具有更高的特异性。