Temporal variation of Skeletonema community composition from a long-term time series in Narragansett Bay identified using high-throughput DNA sequencing
Temporal variation of Skeletonema community composition from a long-term time series in Narragansett Bay identified using high-throughput DNA sequencing
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DOI：
10.3354/meps11843
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发表时间：
2016-09-08
影响因子：
2.5
通讯作者：
Rynearson, Tatiana A.
中科院分区：
文献类型：
--
作者：
Canesi, Kelly L.;Rynearson, Tatiana A.
浮游植物的种类并不总是通过光学显微镜的形态来识别，这使得推断单个物种的生态和生物地球化学重要性成为一项困难的任务。在这里，使用显微镜和高通量DNA测序相结合的方法来检查纳拉甘西特湾（NBay）长期浮游生物时间序列中骷髅藻属硅藻的形态隐生和伪隐生物种，其中骷髅藻具有重要的生态意义，占表层水中微型浮游生物细胞的99%。利用新开发的骷髅特异性引物对已知物种模拟浮游植物群落的28S rDNA进行扩增和测序。序列数据中物种的相对丰度与预期的丰度不匹配，表明即使在近亲硅藻物种之间，28S拷贝数也会有很大的差异。从2008 - 2013年采集的75份野外样本中扩增28S rDNA。共鉴定出7种骨骼线虫，其中5种为NBay新发现种。骨骼肌物种组成季节性强，与水温呈显著相关。冬春群落和夏秋群落差异显著，物种丰富度分别为低和高。将序列数据与光镜计数相结合，定量分析了冬春期的物种丰度，结果表明马里诺骨骼肌是冬春期的数量优势种。骷髅藻组成的季节变化表明，尽管形态相似，但该属的物种可能适应不同的环境条件，这增加了这种重要的水华形成属的物种组成可能随着NBay因人为影响而升高的水温而变化的可能性。
Phytoplankton species cannot always be identified by their morphology using light microscopy, which makes inferring the ecological and biogeochemical importance of individual species a difficult task. Here, a combination of microscopy and high-throughput DNA sequencing was used to examine morphologically cryptic and pseudo-cryptic species in the diatom genus Skeletonema from the Long-Term Plankton Time Series in Narragansett Bay (NBay), where Skeletonema is ecologically important, comprising up to 99% of microplankton cells in surface waters. The 28S rDNA from mock phytoplankton communities comprising known species was amplified and sequenced using newly developed Skeletonema-specific primers. The relative abundances of species in the sequence data did not match expected abundances, suggesting that 28S copy number can vary greatly, even among closely related diatom species. The 28S rDNA was also amplified from 75 field samples collected from 2008 to 2013. A total of 7 Skeletonema species were identified, including 5 newly detected species from NBay. Skeletonema species composition was highly seasonal and significantly correlated with water temperature. Winter-spring and summer-autumn communities were significantly different and characterized by low and high species richness, respectively. Species abundance during winter-spring was quantified by combining sequence data with light microscopy counts, revealing Skeletonema marinoi as the numerically dominant species during the winter-spring bloom. Seasonal variation in Skeletonema composition suggests that, although morphologically similar, species in this genus are likely adapted to different environmental conditions, raising the possibility that species composition of this important bloom-forming genus may shift as water temperatures in NBay increase due to anthropogenic influences.