g. due to providing nutrients, while S-symbionts have LY333531 in vitro a beneficial but not essential role for host insect survival (for reviews see [3] and [6]). In many insects, endosymbionts are located in PD-1/PD-L1 Inhibitor 3 solubility dmso specialized organs (referred to as bacteriomes or mycetomes) and their inheritance usually follows a strict vertical transmission from mother to offspring. Understanding

relationships between insect hosts and their endosymbiotic bacteria is not only relevant from an evolutionary point of view, but can also aid in the identification of new targets for insect pest control [7] as well as for biotechnology and biomedicine [3]. Yet, since many of the relevant microorganisms cannot be cultured, their identification and functional characterization was so far difficult or not possible at all. Lately, the accessibility

of novel genomic techniques, in particular next generation sequencing (NGS) technologies represent new, cost-efficient and fast strategies to depict microbial diversity without the need for culturing click here the respective organisms [8]. With these techniques thousands of sequence reads can be analysed in parallel allowing an extensive assessment of bacterial diversity within insects. As a target for bacterial NGS projects, ribosomal DNA genes (rDNA) like the 16S rDNA, also used for the taxonomic classification of bacterial species [9], have frequently been applied for analysing the bacterial microbial community in metagenomic studies of soil [10, 11], mines [12], the deep sea [13] or oral human microflora [14]. In this study, we used high-throughput tag-encoded FLX amplicon pyrosequencing [15] to characterise bacterial communities associated with four

different weevil species of the genus Otiorhynchus Germar (Coleoptera: Curculionidae). Members of this genus are polyphagous and are regarded as pests of a variety of ornamental and nursery plants worldwide. Their soilborne larvae feed on the host plants’ roots which may be lethal in particular for younger plants or recently transplanted cuttings. Further, feeding damage of adults on the plants foliage may reduce the market value of ornamentals. For these reasons weevils are often controlled by intensive insecticide applications [16]. Moreover, Otiorhynchus spp. can serve Isoconazole as a model genus for understanding the evolution of asexual reproduction, since it includes species both reproducing mostly parthenogenetically (like O. sulcatus and O. rugosostriatus) as well as sexually (like O. salicicola and O. armadillo) [17, 18]. Here, by applying 454 sequencing technology, we show that weevils of the genus Otiorhynchus are associated with several endosymbiotic bacteria. This study is the first to report Rickettsia and “Candidatus Nardonella” endosymbionts – the ancestral endosymbiont of weevils – in Otiorhynchus spp..