Physiological homogeneity among the endosymbionts of Riftia pachyptila and Tevnia jerichonana revealed by proteogenomics
Physiological homogeneity among the endosymbionts of Riftia pachyptila and Tevnia jerichonana revealed by proteogenomics
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DOI：
10.1038/ismej.2011.137
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发表时间：
2012-04-01
期刊：
影响因子：
11
通讯作者：
Schweder, Thomas
中科院分区：
文献类型：
--
作者：
Gardebrecht, Antje;Markert, Stephanie;Schweder, Thomas
两种近缘关系密切的深海管虫--厚壁里夫氏虫和杰氏锥虫--都完全依靠单一种类的硫化物氧化内共生细菌提供营养。然而，它们确实在截然不同的地球化学条件下茁壮成长。对内共生菌进行了详细的蛋白质组学比较，并对地球化学环境进行了原位表征，以研究它们在两个各自宿主中的作用和表达谱。元基因组表明，内共生体具有高度的同质性。编码某些关键代谢功能的酶的基因序列被发现有99.9%的一致性。在蛋白质组水平上，共生体表现出非常一致的代谢特征，尽管在各自寄主的羽流水平上存在明显不同的地球化学条件。与硫代谢、碳固定和氧化胁迫反应相关的共生体酶的表达只有很小的变化。虽然这些变化与每个宿主所经历的普遍环境状况相对应，但我们的数据有力地表明，这两个管虫物种能够有效地减弱栖息地条件的差异，从而为它们的共生体提供相似的微环境。《ISME期刊》(2012年)6766-776；doi：10.1038/ismej.2011.137；2011年10月20日在线发布
The two closely related deep-sea tubeworms Riftia pachyptila and Tevnia jerichonana both rely exclusively on a single species of sulfide-oxidizing endosymbiotic bacteria for their nutrition. They do, however, thrive in markedly different geochemical conditions. A detailed proteogenomic comparison of the endosymbionts coupled with an in situ characterization of the geochemical environment was performed to investigate their roles and expression profiles in the two respective hosts. The metagenomes indicated that the endosymbionts are genotypically highly homogeneous. Gene sequences coding for enzymes of selected key metabolic functions were found to be 99.9% identical. On the proteomic level, the symbionts showed very consistent metabolic profiles, despite distinctly different geochemical conditions at the plume level of the respective hosts. Only a few minor variations were observed in the expression of symbiont enzymes involved in sulfur metabolism, carbon fixation and in the response to oxidative stress. Although these changes correspond to the prevailing environmental situation experienced by each host, our data strongly suggest that the two tubeworm species are able to effectively attenuate differences in habitat conditions, and thus to provide their symbionts with similar micro-environments. The ISME Journal (2012) 6, 766-776; doi: 10.1038/ismej.2011.137; published online 20 October 2011