Seasonal dynamics of free-living tintinnid ciliate communities revealed by environmental sequences from the North-West Mediterranean Sea
Seasonal dynamics of free-living tintinnid ciliate communities revealed by environmental sequences from the North-West Mediterranean Sea
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DOI：
10.1111/1574-6941.12224
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发表时间：
2014-02-01
影响因子：
4.2
通讯作者：
Lopez-Garcia, Purificacion
中科院分区：
文献类型：
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作者：
Bachy, Charles;Moreira, David;Lopez-Garcia, Purificacion
丁丁目（Tintinnida）是一组广泛存在于沿海沃茨的浮游纤毛虫，其物种多样性可以用分子生物学方法进行描述。我们研究了地中海沿岸地区一年内锡虫多样性的时间变化（法国滨海自由城）在五个不同的深度（5，25，50，100和160米）和一个额外的一年，在50米深的变性凝胶梯度电泳（DGGE）的社区指纹与直接PCR扩增，克隆和测序的小亚基（SSU），5.8S，和大亚基（LSU）rRNA基因以及相应的内转录间隔区（ITS）。我们扩增了所有样本中的tintinnid序列。所有确定的tintinnid类型密切相关的描述的物种，显示有一个很好的系统发育参考序列数据集，使这些沃茨的tintinnid多样性的准确估计。Tintinnid群落组成具有明显的季节变化。令人惊讶的是，tintinnid SSU rDNA为基础的物种组成没有显示出任何明确的关系，测量的环境参数（温度，盐度，光，浮游植物生物量）。然而，使用UniFrac的tintinnid社区组成的比较显示了三个显着的序列分组集群，分别在冬季，秋季和夏季收集的样品，导致的假设，季节对tintinnid社区组成的影响可能与生物参数。此外，基于串联的SSU+LSU rDNA和ITS序列的系统发育树显示出比单独的SSU rDNA更好的分辨率来区分密切相关的物种。
The species-rich order Tintinnida is a group of planktonic ciliates ubiquitous in coastal marine waters, which can be well described using molecular estimates of diversity. We studied temporal changes of tintinnid diversity over 1year in a coastal Mediterranean Sea location (Villefranche-sur-Mer, France) at five different depths (5, 25, 50, 100, and 160m) and one additional year at 50m depth by combining denaturing gel gradient electrophoresis (DGGE) community fingerprinting with direct PCR amplification, cloning and sequencing of small subunit (SSU), 5.8S, and large-subunit (LSU) rRNA genes together with the corresponding internal transcribed spacers (ITS). We amplified tintinnid sequences in all samples. All identified phylotypes were closely related to described species, showing that there is a good phylogenetic reference sequence data set allowing accurate estimation of tintinnid diversity in these waters. Tintinnid community composition exhibited marked seasonal changes. Surprisingly, the tintinnid SSU rDNA-based species composition did not show any clear relationship to measured environmental parameters (temperature, salinity, light, phytoplankton biomass). Nonetheless, the comparison of tintinnid community composition using UniFrac revealed three significant clusters of sequences grouping, respectively, samples collected in winter, autumn, and summer, leading to the hypothesis that seasonal effects on tintinnid community composition might be related to biotic parameters. In addition, phylogenetic trees based on the concatenated SSU+LSU rDNA and ITS sequences showed a better resolution than SSU rDNA alone to discriminate closely related species.