Culturing and environmental DNA sequencing uncover hidden kinetoplastid biodiversity and a major marine clade within ancestrally freshwater Neobodo designis.
Culturing and environmental DNA sequencing uncover hidden kinetoplastid biodiversity and a major marine clade within ancestrally freshwater Neobodo designis.
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培养和环境 DNA 测序揭示了隐藏的动质体生物多样性和祖先淡水 Neobodo designis 中的主要海洋分支。
DOI：
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发表时间：
2005
影响因子：
2.8
通讯作者：
T. Cavalier
中科院分区：
文献类型：
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作者：
S. von der Heyden;T. Cavalier
舟形鞭毛虫是淡水、土壤和海洋生境中丰富的自由生活的原生动物，全球生物多样性采样不足。为了研究藻类的整体多样性，用动质体特异的聚合酶链式反应从16个不同环境样品的DNA中扩增并测序了18S rRNA基因，在39个不同的动质体序列中，有35个属于变动体亚类，其中大多数属于Neobodo属或Bodo Saltans种，而4个类群属于原动体亚类(鱼)。为了研究Neobodo属淡水和海洋成员之间的差异，我们培养了26个新的Neobodo Designis菌株，并对它们的18S rRNA基因进行了测序。结果表明，形态种N.Designis是一个非常古老的物种复合体，一个主要的海洋分支嵌套在较老的淡水分支之间，这表明在它们漫长的历史中，这些分支在生理上受到限制，不能在这些环境之间移动。其他主要的贝类分支显示海洋和淡水菌株之间的分离程度较小，但在所有谱系中都具有广泛的遗传多样性，而且盐藻亚支在生物地理上的分布明显不同。利用18S rRNA基因的支系特异性引物对两个亚支进行了遗传多样性和全球分布的检测。环境DNA序列和培养DNA序列之间的不重叠表明，全球有数百、甚至数千种不同的自由生活类生物的rRNA基因序列。
Bodonid flagellates (class Kinetoplastea) are abundant, free-living protozoa in freshwater, soil and marine habitats, with undersampled global biodiversity. To investigate overall bodonid diversity, kinetoplastid-specific PCR primers were used to amplify and sequence 18S rRNA genes from DNA extracted from 16 diverse environmental samples; of 39 different kinetoplastid sequences, 35 belong to the subclass Metakinetoplastina, where most group with the genus Neobodo or the species Bodo saltans, whilst four group with the subclass Prokinetoplastina (Ichthyobodo). To study divergence between freshwater and marine members of the genus Neobodo, 26 new Neobodo designis strains were cultured and their 18S rRNA genes were sequenced. It is shown that the morphospecies N. designis is a remarkably ancient species complex with a major marine clade nested among older freshwater clades, suggesting that these lineages were constrained physiologically from moving between these environments for most of their long history. Other major bodonid clades show less-deep separation between marine and freshwater strains, but have extensive genetic diversity within all lineages and an apparently biogeographically distinct distribution of B. saltans subclades. Clade-specific 18S rRNA gene primers were used for two N. designis subclades to test their global distribution and genetic diversity. The non-overlap between environmental DNA sequences and those from cultures suggests that there are hundreds, possibly thousands, of different rRNA gene sequences of free-living bodonids globally.