Department of Entomology, University of Kentucky, Lexington, KY, 40546, USA.
Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, 94720, USA.
Microb Ecol. 2020 Feb;79(2):472-481. doi: 10.1007/s00248-019-01411-w. Epub 2019 Jul 12.
Maternally inherited bacterial endosymbionts are common in arthropods, but their distribution and prevalence are poorly characterized in many host taxa. Initial surveys have suggested that vertically transmitted symbionts may be particularly common in spiders (Araneae). Here, we used diagnostic PCR and high-throughput sequencing to evaluate symbiont infection in 267 individual spiders representing 14 species (3 families) of agricultural spiders. We found 27 operational taxonomic units (OTUs) that are likely endosymbiotic, including multiple strains of Wolbachia, Rickettsia, and Cardinium, which are all vertically transmitted and frequently associated with reproductive manipulation of arthropod hosts. Additional strains included Rickettsiella, Spiroplasma, Rhabdochlamydia, and a novel Rickettsiales, all of which could range from pathogenic to mutualistic in their effects upon their hosts. Seventy percent of spider species had individuals that tested positive for one or more endosymbiotic OTUs, and specimens frequently contained multiple symbiotic strain types. The most symbiont-rich species, Idionella rugosa, had eight endosymbiotic OTUs, with as many as five present in the same specimen. Individual specimens within infected spider species had a variety of symbiotypes, differing from one another in the presence or absence of symbiotic strains. Our sample included both starved and unstarved specimens, and dominant bacterial OTUs were consistent per host species, regardless of feeding status. We conclude that spiders contain a remarkably diverse symbiotic microbiota. Spiders would be an informative group for investigating endosymbiont population dynamics in time and space, and unstarved specimens collected for other purposes (e.g., food web studies) could be used, with caution, for such investigations.
母体遗传的细菌内共生体在节肢动物中很常见，但在许多宿主分类群中，它们的分布和流行情况还没有得到很好的描述。初步调查表明，垂直传播的共生体在蜘蛛（蜘蛛目）中可能特别常见。在这里，我们使用诊断 PCR 和高通量测序来评估代表 14 种农业蜘蛛物种（3 科）的 267 只个体蜘蛛的共生体感染情况。我们发现了 27 个可能是内共生的操作分类单元（OTU），包括多种沃尔巴克氏体、立克次氏体和卡多氏体菌株，这些菌株都是垂直传播的，并且经常与节肢动物宿主的生殖操纵有关。其他菌株包括立克次氏体、螺旋体、Rhabdochlamydia 和一种新型的立克次体目，它们对宿主的影响可能从致病到共生不等。70%的蜘蛛物种的个体检测出一种或多种内共生 OTU 呈阳性，标本中经常含有多种共生菌株类型。共生体最丰富的物种 Idionella rugosa 有 8 种内共生 OTU，其中多达 5 种存在于同一标本中。感染蜘蛛物种的个体标本具有多种共生型，彼此之间在共生菌株的存在或不存在方面存在差异。我们的样本包括饥饿和未饥饿的标本，并且无论宿主的进食状态如何，优势细菌 OTU 都是一致的。我们的结论是，蜘蛛体内存在着非常多样化的共生微生物群。蜘蛛将是一个很有意义的群体，可以用来研究内共生体在时间和空间上的种群动态，并且可以谨慎地利用为其他目的（例如，食物网研究）收集的未饥饿标本进行此类研究。
