Overlap and discrepancies between ecotypes, genotypes and morphotypes of Antarctic and Arctic nanofauna

南极和北极纳米动物生态型、基因型和形态型之间的重叠和差异

• 批准号: 27173492
• 负责人: Professor Dr. Hartmut Arndt
• 金额: --
• 依托单位: Workgroup General Ecology
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/27173492?language=en
• 关键词: Overlap; discrepancies; between; ecotypes; genotypes

Heterotrophic nanoflagellates are major consumers of bacteria in the polar regions and contribute significantly to the carbon flux from DOC via bacteria to larger organisms such as ciliates and metazoans. Heterotrophic flagellate biomass may greatly exceed bacterial biomass in the sea ice. According to our recent molecular biological and morphological studies of Antarctic and Arctic nanofauna, morphological investigations reveal only limited taxonomic resolution for these tiny organisms (mainly 2-8um cell size). Many morphotypes contain several genotypes with sometimes high evolutionary distances (p-distances of SSU rDNA). To study the role of endemism in polar waters, we want to analyze discrepancies and overlaps between morphotypes, genotypes and ecotypes of selected nanoflagellates to draw conclusions regarding the possible effects of small changes in temperature on the sensitive Antarctic and Arctic ice biota. We will take samples from Antarctic and Arctic sites, establish cultures of nanoflagellates and analyse them combining morphological, molecular biological and ecological methods. We will use new clonal cultures in addition to already established cultures of Antarctic and Arctic isolates to study the tolerance of single genotypes regarding temperature, salinity and food composition. Knowing more about the role of biodiversity of the most important bacterivorous components of Antarctic and Arctic ecosystems should support our understanding of ecological processes in polar regions.

异养纳米鞭毛虫是极地地区细菌的主要消耗者，对通过细菌从DOC到纤毛虫和后生动物等较大生物的碳通量有很大贡献。异养鞭毛虫的生物量可能大大超过海冰中的细菌生物量。根据我们最近对南极和北极纳米动物的分子生物学和形态研究，形态调查显示这些微小生物的分类分辨率有限(主要是2-8微米大小的细胞)。许多形态类型包含多个基因类型，有时进化距离很高(SSU rDNA的p距离)。为了研究极地水域特有现象的作用，我们想要分析选定的纳米鞭毛虫的形态类型、基因类型和生态型之间的差异和重叠，以得出温度微小变化对敏感的南极和北极冰区生物群可能产生的影响的结论。我们将从南极和北极采集样本，建立纳米鞭毛虫的培养，并结合形态、分子生物学和生态学方法进行分析。除了已经建立的南极和北极分离株的培养外，我们还将使用新的克隆培养物来研究单一基因类型在温度、盐度和食物组成方面的耐受性。更多地了解南极和北极生态系统中最重要的食菌成分的生物多样性的作用，应该有助于我们理解极地地区的生态过程。

项目成果

Cryptic diversity within the choanoflagellate morphospecies complex Codosiga botrytis - phylogeny and morphology of ancient and modern isolates.

• DOI: 10.1016/j.ejop.2012.01.004
• 发表时间: 2012-11
• 期刊: European journal of protistology
• 影响因子: 2.9
• 作者: Daniel Stoupin;Á. K. Kiss;H. Arndt;A. Shatilovich;D. Gilichinsky;F. Nitsche