Diversity and evolutionary origin of Polish freshwater dinoflagellates

明确的科学名称是正确识别和随后应用生物物种的先决条件。单细胞生物，只能在显微镜下识别，特别容易出现分类混乱，相应的标准（即类型）材料往往保存不良或完全丢失。近年来，分子方法已成为解决鉴定问题的重要工具。单细胞浮游生物的一个重要的生态和经济组是鞭毛藻，这一提案的主题。波兰是在一个世纪前被描述的淡水鞭毛藻种类最多的国家。该国有1万多个湖泊，大部分起源于过去的冰期，也是研究淡水生物进化多样化的非凡系统。在这里，我们的目标是在类型地点收集生活材料并建立生活菌株，以便对相应的藻类进行重新调查。使用光镜和电子显微镜研究形态将界定波兰物种，并将对鞭毛纲动物的特征进化有更多的了解。系统发育关系将使用最大似然方法从基于rRNA和其他信息位点的分子树中推断出来。我们将测试淡水鞭毛藻是否广泛分布于整个欧洲，还是作为特有物种出现在孤立的栖息地（如湖泊）。鞭毛藻群落的组成可能是a)最近从海洋环境过渡到淡水环境后的辐射，以及b)在更新世之前形成的波罗的海脊之前对淡水的适应以及随后向当前栖息地的扩散。时间分化事件将进一步启发中欧淡水鞭毛藻的起源和多样化。该项目的结果将有助于在公共数据库和收藏中永久记录鞭毛藻的形态和分子多样性。

Unambiguous scientific names are the prerequisite for proper identification and therefore any subsequent application of biological species. Unicellular organisms, which can only be identified under the microscope, are particularly prone to taxonomic confusion, and corresponding standard (i.e., type) material often is poorly preserved or entirely lost. Recently, molecular methods have become an essential tool to resolve identification issues. An ecologically and economically important group of unicellular plankton organisms are dinoflagellates, the subject of this proposal. Poland is the country, from which the greatest number of freshwater dinoflagellate species have been described, partly a century ago. With more than 10,000 lakes mostly originated during the past Glacial Maximum, the country is also an extraordinary system to study evolutionary diversification of freshwater organisms. Here we aim to collect living material at type localities and to establish living strains, allowing re-investigation of the corresponding algae. Study of morphology using light and electron microscopy will circumscribe Polish species and will shed more light on character evolution in dinoflagellates. Phylogenetic relationships will be inferred from molecular trees based on rRNA and other informative loci using maximum likelihood methods. We will test whether freshwater dinoflagellates are widely distributed across Europe or rather occur in isolated habitats (such as lakes) as endemic species. Composition of dinoflagellate communities may result from both a) radiations after recent transitions from the marine into the freshwater environment as well as b) adaptation to freshwater prior to the formation of the Baltic Ridge older then the Plesitocene and subsequent dispersal to the current habitats. Timing divergence events will further enlighten origin and diversification of Central European freshwater dinoflagellates. Results of this project will contribute to the permanent documentation of the morphological and molecular diversity of dinoflagellates in public data bases and collections.