Methylmercury in Antarctic Krill Microbiomes.

海洋食物网可使哺乳动物体内的神经毒素-一甲基汞（MMHg）集中在高营养级消费者体内。尽管地处偏远，但南极沿海海洋生态系统仍将MMHg积累并产生生物放大作用，达到了在低纬度和北极观测到的水平。 海洋沉积物和海洋中的其他缺氧生境是汞发生甲基化的典型区域，这些区域可能是MMHg产生的地方。 磷虾，更具体地说是它们的消化道，可能是南极洲一个以前未知的可能产生MMHg的地点。 如果磷虾中正在产生一甲基汞，那么目前关于食物网中的生物累积以及导致南极海洋中汞产生和累积的过程的观点即使不能改变，也可以得到更好的信息。 该项目将通过检测参与汞转化的基因，对磷虾肠道微生物组、微生物组的基因组含量和生产一甲基汞的潜力进行初步评估。 通过分析磷虾肠道微生物组，该项目将提供有关动物-微生物相互作用及其在全球重要的生物地球化学循环中的潜在作用的见解。 该项目将对磷虾肠道微生物组、微生物组基因组含量和一甲基汞生产潜力进行初步评估。 磷虾消化道中微生物的多样性和代谢特征将使用大规模并行Illumina DNA测序技术进行评估，以产生16 S rRNA基因文库和组装的完整宏基因组。该项目还将量化汞甲基化基因hgcAB的丰度和表达，并确定它们在微生物群落中的分类学关系。 该项目产生的环境宏基因组、16 S rRNA基因清单将为极地科学界提供有价值的数据库和实验工具，用于研究南极沿海微生物生态学和海洋地球化学。 该项目将寻求为了解极端微生物群落的多样性和确定潜在的独特和有用的生物活性化合物提供一个更广泛的窗口。除了公众教育和宣传外。 该项目将在参与机构培训研究生并提供教育和推广机会

Marine food webs can concentrate monomethylmercury (MMHg), a neurotoxin in mammals, in upper trophic level consumers. Despite their remoteness, coastal Antarctic marine ecosystems accumulateand biomagnify MMHg to levels observed at lower latitudes and in the Arctic. Marine sediments and other anoxic habitats in the oceans are typical areas where methylation of mercury occurs and these are likely places where MMHg is being produced. Krill, and more specifically their digestive tracts, may be a previously unaccounted for site where the production of MMHg may be occurring in the Antarctic. If monomethylmercury production is occurring in krill, current views regarding bioaccumulation in the food web and processes leading to the production and accumulation of mercury in the Antarctic Ocean could be better informed, if not transformed. This project will conduct a preliminary assessment of the krill gut microbiomes, the microbiome's genomic content and potential for production of monomethyl mercury by detecting the genes involved in mercury transformations. By analyzing the krill gut microbiome, the project will provide insights regarding animal-microbe interactions and their potential role in globally important biogeochemical cycles. This project will conduct a preliminary assessment of the krill gut microbiomes, the microbiomes genomic content and potential for production of monomethylmercury. The diversity and metabolic profiles of microorganisms in krill digestive tracts will be evaluated using massively parallel Illumina DNA sequencing technology to produce 16S rRNA gene libraries and assembled whole metagenomes. The project will also quantify the abundance and expression of Hg methylation genes, hgcAB, and identify their taxonomic affiliations in the microbiome communities. Environmental metagenomes, 16S rRNA gene inventories produced from this project will provide the polar science community with valuable databases and experimental tools with which to examine coastal Antarctic microbial ecology and biogeochemistry. The project will seek to provide a wider window into the diversity of extremophile microbial communities and the identification of potentially unique and useful bioactive compounds. In addition to public education and outreach. This project will train graduate students and provide educational and outreach opportunities at the participating institutions