Wang Yongjie, Stingl Ulrich, Anton-Erxleben Friederike, Zimmer Martin, Brune Andreas
Zoologisches Institut, Christian-Albrechts-Universität, Olshausenstrasse 40, 24098 Kiel, Germany.
Arch Microbiol. 2004 Apr;181(4):299-304. doi: 10.1007/s00203-004-0655-7. Epub 2004 Feb 10.
The midgut glands (hepatopancreas) of terrestrial isopods are densely colonized by hitherto uncultivated bacteria. In the case of the Common Woodlouse, Porcellio scaber (Crustacea: Isopoda), the symbionts represent a novel lineage in the alpha-subdivision of Proteobacteria. Based on comparative sequence analysis of their 16S rRNA genes, their closest (albeit distant) relatives were among the Rickettsiales, which are intracellular symbionts or pathogens of many animals. Transmission electron microscopy and in situ hybridization with fluorescently labeled oligonucleotide probes revealed a homogeneous population of symbionts intimately associated with the endothelium of the hepatopancreas, which apparently interact with the microvilli of the brush border by means of a stalk-like cytoplasmic appendage. Based on isolated phylogenetic position and unique cytological properties, the provisional name ' Candidatus Hepatincola porcellionum' is proposed to classify this new taxon of Rickettsiales colonizing the hepatopancreas of P. scaber.
陆生等足类动物的中肠腺（肝胰腺）被迄今尚未培养的细菌密集定殖。以普通潮虫（Porcellio scaber，甲壳纲：等足目）为例，这些共生菌代表了变形菌门α亚纲中的一个新谱系。基于对其16S rRNA基因的比较序列分析，它们最接近（尽管亲缘关系较远）的亲属属于立克次氏体目，立克次氏体目是许多动物的细胞内共生菌或病原体。透射电子显微镜和用荧光标记的寡核苷酸探针进行的原位杂交显示，共生菌群体均匀，与肝胰腺内皮紧密相关，它们显然通过一种茎状细胞质附属物与刷状缘的微绒毛相互作用。基于其孤立的系统发育位置和独特的细胞学特性，建议使用临时名称“暂定肝栖潮虫菌（Candidatus Hepatincola porcellionum）”来对这个定殖于普通潮虫肝胰腺中的立克次氏体目的新分类单元进行分类。
