Hydrothermal vent gastropods from the same family (Provannidae) harbour epsilon- and gamma-proteobacterial endosymbionts.
Hydrothermal vent gastropods from the same family (Provannidae) harbour epsilon- and gamma-proteobacterial endosymbionts.
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DOI：
10.1111/j.1462-2920.2005.00753.x
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发表时间：
2005-05
影响因子：
5.1
通讯作者：
H. Urakawa;N. Dubilier;Y. Fujiwara;D. Cunningham;S. Kojima;D. Stahl
中科院分区：
文献类型：
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作者：
H. Urakawa;N. Dubilier;Y. Fujiwara;D. Cunningham;S. Kojima;D. Stahl
在西太平洋弧后盆地发现新的热液喷口系统，揭示了有别于其他喷口的以化学合成为基础的动物群。这些喷口主要由两种相关的腹足类(Alviniccha spp.)和鹦鹉螺Ifremeria nautilei)，它们的鳃中含有共生细菌。我们采用比较16S核糖体RNA(RRNA)基因测序和rRNA靶向探针原位杂交的方法对Alviniccha sp.的细菌共生菌进行了研究。和西太平洋马努斯盆地的I.Nautilei。分析表明，这两种腹足类虽然属于同一科，但含有系统发育上相距较远的化学共生体，表明这些内共生体的起源是独立的。鹦鹉螺杆菌内共生菌与硫氧化细菌在伽马变形杆菌内聚集在一起，就像以前从含有硫代自养原核生物的广泛多样性的宿主分类群中鉴定的所有内共生体一样。相反，Alviniccha内共生菌与epsilon变形杆菌中的硫氧化细菌有关。这些结果表明，来自变形杆菌的细菌也能够与来自化学合成环境的海洋无脊椎动物形成内生共生关系。更广泛地说，内生共生的生活方式现在被证明分布在所有公认的变形杆菌类别中。
The discovery of new hydrothermal vent systems in the back-arc basins of the Western Pacific revealed chemosynthesis-based faunal communities distinct from those of other vents. These vents are dominated by two related gastropods (Alviniconcha spp. and Ifremeria nautilei) that harbour symbiotic bacteria in their gills. We used comparative 16S ribosomal RNA (rRNA) gene sequencing and in situ hybridization with rRNA-targeted probes to characterize the bacterial symbionts of Alviniconcha sp. and I. nautilei from the Manus Basin in the Western Pacific. The analyses revealed that these two gastropod species, although affiliated with the same family, harbour phylogenetically distant chemosymbionts, suggesting independent origins of these endosymbioses. The I. nautilei endosymbiont clusters with sulfur-oxidizing bacteria within the gamma-Proteobacteria, as is the case for all previously characterized endosymbionts from a wide diversity of host taxa harbouring thioautotrophic prokaryotes. In contrast, the Alviniconcha endosymbiont is affiliated with sulfur-oxidizing bacteria within the epsilon-Proteobacteria. These results show that bacteria from the epsilon-Proteobacteria are also capable of forming endosymbiotic associations with marine invertebrates from chemosynthetic environments. More generally, the endosymbiotic lifestyle is now shown to be distributed throughout all recognized classes of the Proteobacteria.