Vampires in the oceans: predatory cercozoan amoebae in marine habitats
Vampires in the oceans: predatory cercozoan amoebae in marine habitats
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DOI：
10.1038/ismej.2013.116
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发表时间：
2013-12-01
期刊：
影响因子：
11
通讯作者：
Bass, David
中科院分区：
文献类型：
--
作者：
Berney, Cedric;Romac, Sarah;Bass, David
吸血鬼变形虫是主要从土壤和淡水栖息地中发现的藻类、真菌、原生动物和小型后生动物的捕食者。在过去的几十年里，由于已知物种独特的取食方式，它们是极少数从形态和生态角度受到关注的异养裸体、纤毛类和网状原生动物之一。然而，它们的生物多样性的真实程度在很大程度上仍然不得而知。在这里，我们使用培养和序列数据库挖掘的互补方法来解决这个问题，将我们的努力集中在海洋环境上，那里的吸血鬼知之甚少。我们提出了10个新的金龟子分离物，8个来自海洋或微咸水沉积物，2个来自土壤或淡水沉积物。前者的两个对应于之前没有序列数据的海链霉属Grell和Penardia Cash。小亚基核糖体DNA分析证实，它们都与之前测序的吸血鬼类有关。对NCBI GenBank数据库和欧洲生物标记联盟产生的454个序列数据进行了详尽的筛选，发现了数百个不同的环境毒蛾序列。我们发现，吸血鬼的种类比之前认为的要多得多，特别是在海洋栖息地。我们的新分离株几乎涵盖了本研究中揭示的吸血鬼类昆虫序列的全部系统发育范围，为将环境DNA调查数据与表型信息相结合提供了难得的机会。然而，我们在吸血鬼类(特别是在海洋沉积物和土壤中)中强调的非常大的遗传多样性，与我们在我们的分离株中观察到的反常的低形态差异形成了鲜明的对比。
Vampire amoebae (vampyrellids) are predators of algae, fungi, protozoa and small metazoans known primarily from soils and in freshwater habitats. They are among the very few heterotrophic naked, filose and reticulose protists that have received some attention from a morphological and ecological point of view over the last few decades, because of the peculiar mode of feeding of known species. Yet, the true extent of their biodiversity remains largely unknown. Here we use a complementary approach of culturing and sequence database mining to address this issue, focusing our efforts on marine environments, where vampyrellids are very poorly known. We present 10 new vampyrellid isolates, 8 from marine or brackish sediments, and 2 from soil or freshwater sediment. Two of the former correspond to the genera Thalassomyxa Grell and Penardia Cash for which sequence data were previously unavailable. Small-subunit ribosomal DNA analysis confirms they are all related to previously sequenced vampyrellids. An exhaustive screening of the NCBI GenBank database and of 454 sequence data generated by the European BioMarKs consortium revealed hundreds of distinct environmental vampyrellid sequences. We show that vampyrellids are much more diverse than previously thought, especially in marine habitats. Our new isolates, which cover almost the full phylogenetic range of vampyrellid sequences revealed in this study, offer a rare opportunity to integrate data from environmental DNA surveys with phenotypic information. However, the very large genetic diversity we highlight within vampyrellids (especially in marine sediments and soils) contrasts with the paradoxically low morphological distinctiveness we observed across our isolates.