Durand Audrey-Anne, Bergeron Amélie, Constant Philippe, Buffet Jean-Philippe, Déziel Eric, Guertin Claude
INRS-Institut Armand-Frappier, Laval, QC, H7V1B7, Canada.
Sci Rep. 2015 Nov 26;5:17190. doi: 10.1038/srep17190.
Many bark beetles belonging to the Dendroctonus genus carry bacterial and fungal microbiota, forming a symbiotic complex that helps the insect to colonize the subcortical environment of the host tree. However, the biodiversity of those bacteria at the surface of the cuticle or inside the body parts of bark beetles is not well established. The aim of this study was to characterize the bacterial microbiome associated with the eastern larch beetle, Dendroctonus simplex, using bacterial 16S rRNA gene pyrosequencing. The ecto- and endomicrobiome and the subcortical galleries were investigated. Several bacterial genera were identified, among which Pseudomonas, Serratia and Yersinia are associated with the surface of the beetle cuticle, and genera belonging to Enterobacteriaceae and Gammaproteobacteria with the interior of the insect body. The index of dissimilarity indicates that the bacterial microbiome associated with each environment constitutes exclusive groups. These results suggest the presence of distinct bacterial microbiota on the surface of the cuticle and the interior of D. simplex body. Additionally, the bacterial diversity identified in the galleries is substantially different from the ectomicrobiome, which could indicate a selection by the insect. This study reports for the first time the identification of the eastern larch beetle microbiome.
许多属于齿小蠹属的树皮甲虫携带细菌和真菌微生物群，形成一种共生复合体，帮助这种昆虫在寄主树的皮层下环境中定殖。然而，在树皮甲虫角质层表面或身体部位内部的那些细菌的生物多样性尚未明确。本研究的目的是利用细菌16S rRNA基因焦磷酸测序来表征与东部落叶松甲虫（Dendroctonus simplex）相关的细菌微生物组。对其体表和体内微生物组以及皮层下虫道进行了研究。鉴定出了几个细菌属，其中假单胞菌属、沙雷氏菌属和耶尔森氏菌属与甲虫角质层表面相关，而肠杆菌科和γ-变形菌纲的属与昆虫体内相关。差异指数表明与每个环境相关的细菌微生物组构成了独特的群体。这些结果表明在D. simplex角质层表面和体内存在不同的细菌微生物群。此外，在虫道中鉴定出的细菌多样性与体表微生物组有很大不同，这可能表明是昆虫进行了选择。本研究首次报道了东部落叶松甲虫微生物组的鉴定结果。
