Investigating Algal Communities in Lacustrine and Hydro-Terrestrial Environments of East Antarctica Using Deep Amplicon Sequencing
Investigating Algal Communities in Lacustrine and Hydro-Terrestrial Environments of East Antarctica Using Deep Amplicon Sequencing
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DOI：
10.3390/microorganisms8040497
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发表时间：
2020-04-01
期刊：
影响因子：
4.5
通讯作者：
Harada, Naomi
中科院分区：
文献类型：
--
作者：
Hirose, Yuu;Shiozaki, Takuhei;Harada, Naomi
南极洲是地球上最极端的环境之一，温度低，营养水平低。南极洲的生物主要生活在沿海的无冰地区，约占大陆表面的0.18%。蓝细菌和真核藻类是南极洲重要的初级生产者，因为它们可以利用太阳能从二氧化碳和水合成有机化合物。然而，南极光合藻类的群落结构尚未在分子水平上得到充分的研究。在这项研究中，我们收集了不同的藻类样品在湖泊和水陆环境的Langhovde和Skarvsnes，这是两个无冰区在东南极洲。我们对16 S核糖体核糖核酸（rRNA）和18 S rRNA基因进行了深度扩增子测序，并在单核苷酸差异分辨率下探索了这些基因的序列变体（SV）的分布。在大多数样品中鉴定出丝状蓝藻属的SV，包括Leptolyngbya，Pseudanabaena，Phormidium，Nodosilinea，Geitlerinama和Tychonema，而Phormidesmis SV分布在较少的样品中。我们还检测到单细胞，多细胞或异形胞形成蓝藻菌株，但在相对较小的丰度。真核藻类的SV，绿藻门，隐藻门，和Ochrophyta广泛分布在所收集的样品。此外，在Langhovde沿海地区，有一种红色的真核生物，Geminigera cryophile（Cryptophyta）。在大多数样品中，真核生物中的蜘蛛针蚁和/或缓步动物门的齿啮小蜂的SV占优势。我们的数据揭示了Langhovde和Skarvsnes藻类群落的详细结构。这将有助于我们了解南极生态系统，并支持对这一主题的进一步研究。
Antarctica has one of the most extreme environments on Earth, with low temperatures and low nutrient levels. Antarctica's organisms live primarily in the coastal, ice-free areas which cover approximately 0.18% of the continent's surface. Members of Cyanobacteria and eukaryotic algae are important primary producers in Antarctica since they can synthesize organic compounds from carbon dioxide and water using solar energy. However, community structures of photosynthetic algae in Antarctica have not yet been fully explored at molecular level. In this study, we collected diverse algal samples in lacustrine and hydro-terrestrial environments of Langhovde and Skarvsnes, which are two ice-free regions in East Antarctica. We performed deep amplicon sequencing of both 16S ribosomal ribonucleic acid (rRNA) and 18S rRNA genes, and we explored the distribution of sequence variants (SVs) of these genes at single nucleotide difference resolution. SVs of filamentous Cyanobacteria genera, including Leptolyngbya, Pseudanabaena, Phormidium, Nodosilinea, Geitlerinama, and Tychonema, were identified in most of the samples, whereas Phormidesmis SVs were distributed in fewer samples. We also detected unicellular, multicellular or heterocyst forming Cyanobacteria strains, but in relatively small abundance. For SVs of eukaryotic algae, Chlorophyta, Cryptophyta, and Ochrophyta were widely distributed among the collected samples. In addition, there was a red colored bloom of eukaryotic alga, Geminigera cryophile (Cryptophyta), in the Langhovde coastal area. Eukaryotic SVs of Acutuncus antarcticus and/or Diphascon pingue of Tardigrada were dominant among most of the samples. Our data revealed the detailed structures of the algal communities in Langhovde and Skarvsnes. This will contribute to our understanding of Antarctic ecosystems and support further research into this subject.