Functional Sea Ice Ecology: Molecular Biodiversity, Metatranscriptomics and Metagenomics

在“antarktisschwerpunktprogram”（VA 105/13-1&2）的早期DFG项目中，我们从选定的真核极地海冰群落中建立了一个开创性的分子生物多样性和亚转录组学数据集。rDNA序列和cDNA序列片段的系统发育分析一致显示硅藻、褐藻和肺泡藻是优势类群。对于其中一些，全基因组测序项目正在进行或刚刚完成。最近，我们获得了Roche的资助，对海冰群落的总DNA进行了多达3x109个碱基对的测序。本研究的目的是整合海冰生物基因组序列与环境序列的信息，包括SSU rDNA、亚转录组和宏基因组数据。特别是，我们打算1)评估“总”和“活性”真核生物的生物多样性，2)确定区分海冰生物与其他海洋原生生物的基因组特征，3)将活性转录组与相应的宏基因组进行比较，从而确定可能参与使这些生物在海冰中生存的基因/基因功能组。这将为真核海冰微生物在极端环境条件下的基因组组成、变异和表达提供新的见解，并允许对海冰群落的适应潜力做出结论，这是一个特别受到预期的全球变暖威胁的生态系统。

During an earlier DFG project within the “Antarktisschwerpunktprogramm” (VA 105/13-1&2) we have established a seminal molecular biodiversity and metatranscriptomic dataset from selected eukaryotic polar sea ice communities. Phylogenetic analyses of both rDNA sequences and cDNA sequence fragments congruently revealed diatoms, haptophytes, and alveolates as the dominant taxa. For some of these, full genome sequencing projects are underway or just finished. Recently we obtained funding from Roche to sequence up to 3x109 basepairs of total DNA from sea ice communities. The aim of this proposal is to integrate the information available from genome sequences of sea ice organisms with environmental sequences including SSU rDNA, metatranscriptomic and metagenomic data. In particular, we intend to 1) assess “total” and “active” eukaryotic biodiversity, 2) identify genomic features differentiating sea ice organisms from other marine protists, and to 3) compare the active transcriptomes to the corresponding metagenomes and thus identify groups of genes / gene functions which are potentially involved in enabling these organisms to survive in sea ice. This will provide novel insights into genome composition, its variation and expression under extreme environmental conditions in eukaryotic sea ice microorganisms, and allow conclusions on the adaptive potential of sea ice communities, an ecosystem particularly endangered by expected global warming.