Phylogenetic diversity of bacterial endosymbionts in the gutless marine oligochete Olavius loisae (Annelida)
Phylogenetic diversity of bacterial endosymbionts in the gutless marine oligochete Olavius loisae (Annelida)
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DOI：
10.3354/meps178271
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发表时间：
1999-01-01
影响因子：
2.5
通讯作者：
Cavanaugh, CM
中科院分区：
文献类型：
--
作者：
Dubilier, N;Amann, R;Cavanaugh, CM
在化学自养宿主中，与超过 1 种细菌系统型的内共生关联是罕见的。在无肠海洋寡体中，细菌内共生体的 2 种形态类型出现在表皮细胞延伸部分之间的角质层正下方。采用基于 16S 核糖体 RNA 基因的系统发育分析、原位杂交和变性梯度凝胶电泳。结果表明，在无肠寡菌 Olavius loisae 中，2 种细菌形态型对应于 2 个不同系统发育起源的物种。较大的共生体属于变形菌门的γ亚类，并与其他先前描述的化学自养内共生体聚集在一起。较小的共生体代表了变形菌α亚类中的一种新的系统型。这与所有其他具有属于γ或ε变形菌门的共生细菌的化能自养宿主明显不同。此外，在这些宿主中还发现了第三种细菌形态型以及第三种属于螺旋体的独特系统型。这种系统发育多样化的内共生细菌组合在其他海洋无脊椎动物中尚不为人所知。
Endosymbiotic associations with more than 1 bacterial phylotype are rare among chemoautotrophic hosts. In gutless marine oligochetes 2 morphotypes of bacterial endosymbionts occur just below the cuticle between extensions of the epidermal cells. Using phylogenetic analysis, in situ hybridization, and denaturing gradient gel electrophoresis based on 16S ribosomal RNA genes. it is shown that in the gutless oligochete Olavius loisae, the 2 bacterial morphotypes correspond to 2 species of diverse phylogenetic origin. The larger symbiont belongs to the gamma subclass of the Proteobacteria and clusters with other previously described chemoautotrophic endosymbionts. The smaller symbiont represents a novel phylotype within the alpha subclass of the Proteobacteria. This is distinctly different from all other chemoautotrophic hosts with symbiotic bacteria which belong to either the gamma or epsilon Proteobacteria. In addition, a third bacterial morphotype as well as a third unique phylotype belonging to the spirochetes was discovered in these hosts. Such a phylogenetically diverse assemblage of endosymbiotic bacteria is not known from other marine invertebrates.