Emerging Diversity within Chrysophytes, Choanoflagellates and Bicosoecids Based on Molecular Surveys
Emerging Diversity within Chrysophytes, Choanoflagellates and Bicosoecids Based on Molecular Surveys
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DOI：
10.1016/j.protis.2010.10.003
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发表时间：
2011-07-01
期刊：
影响因子：
2.5
通讯作者：
Massana, Ramon
中科院分区：
文献类型：
--
作者：
del Campo, Javier;Massana, Ramon
近年来，大量的水生原生生物的数据已经获得了文化无关的分子方法，揭示了一个大的多样性和新的谱系的存在。然而，与小群体（在克隆丰度方面）相关的序列经常被分析不足，这隐藏了系统发育信息的潜在相关来源。在这里，我们已经搜索了公共数据库的18S rDNA序列的金藻，choanoflagellates和bicosoecids从原生生物的分子调查检索。这三组通常被认为是占大多数的异养鞭毛虫，在微生物食物网的重要功能成分。它们代表了淡水研究中克隆的重要部分，而它们的相对克隆丰度在海洋研究中很低。这一数据集显示的新奇是值得注意的。大多数环境序列是遥远的序列的培养生物，表明在文化中的类群的代表性显着的偏见。此外，他们往往是遥远的序列从其他分子调查，表明测序工作不足，以表征这些群体的原位多样性。具有完整序列的系统发育树呈现了这些组的多样性的最准确的表示，出现了几个完全由环境序列形成的新分支。详尽的数据挖掘序列数据库允许识别新的多样性隐藏在金藻，choanoflagellates和bicosoecids。(C)2010年Elsevier GmbH。All rights reserved.
In recent years, a substantial amount of data on aquatic protists has been obtained from culture-independent molecular approaches, unveiling a large diversity and the existence of new lineages. However, sequences affiliated with minor groups (in terms of clonal abundance) have often been under-analyzed, and this hides a potentially relevant source of phylogenetic information. Here we have searched public databases for 18S rDNA sequences of chrysophytes, choanoflagellates and bicosoecids retrieved from molecular surveys of protists. These three groups are often considered to account for most of the heterotrophic flagellates, an important functional component in microbial food webs. They represented a significant fraction of clones in freshwater studies, whereas their relative clonal abundance was low in marine studies. The novelty displayed by this dataset was notable. Most environmental sequences were distant to sequences of cultured organisms, indicating a significant bias in the representation of taxa in culture. Moreover, they were often distant to sequences from other molecular surveys, suggesting an insufficient sequencing effort to characterize the in situ diversity of these groups. Phylogenetic trees with complete sequences present the most accurate representation of the diversity of these groups, with the emergence of several new clades formed exclusively by environmental sequences. Exhaustive data mining in sequence databases allowed the identification of new diversity hidden inside chrysophytes, choanoflagellates and bicosoecids. (C) 2010 Elsevier GmbH. All rights reserved.