Collaborative Research: A Proteomic Approach to Understanding Cytoprotective Biogenic Sulfur Production in Sea-Ice Diatoms

智力优势：生物硫化合物，如二甲基硫醚（DMS）及其前体二甲基磺基丙酸酯（DMSP）是气候重要的化合物，由于它们对地球的辐射收支的影响。海冰藻类群落是DMSP和DMS的重要生产者，而矛盾的是，这些群落也往往以硅藻为主，而硅藻在远洋环境中产生的DMSP和DMS可以忽略不计。使用基于实验室的方法，包括半连续分批培养和恒化器，将进行一系列模拟海冰内极端环境条件的孵育实验。这些实验将揭示海冰硅藻的应激生理和冷适应。在平行的生理分析，一种新的方法，使用蛋白质组学工具，如2-D差异凝胶电泳将被用来确定哪些蛋白质差异表达在驯化过程中的环境压力。人工神经网络将评估DMSP产生的变化与蛋白质丰度变化之间的关系，并找到有关调节冷驯化、应激回避和DMSP产生的途径的生物标志物信息。更广泛的影响：在全球一级，拟议的研究将提高对什么因素导致冰藻群落中DMSP产量高以及海冰硅藻中DMSP产量如何因全球变暖而变化的科学认识。作为高中外展计划的一部分，我们将开发一个互动网站，以传播有关极地生态系统和硫循环在气候调节中的作用的信息。拟议的研究还将为博士学位提供支持。一个水平的学生将直接参与研究的蛋白质组学部分，一个硕士水平的学生将直接参与研究的生理学部分。此外，参与外展计划的高中生和格莱斯海洋实验室（查尔斯顿学院）REU计划的学生将有机会参与研究工作。

Intellectual Merit: Biogenic sulfur compounds such as dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) are climatically important compounds due to their effects on the Earth's radiation budget. Sea ice algal communities are significant producers of DMSP and DMS, and paradoxically, these communities are also often dominated by diatoms, which in pelagic environments produce negligible DMSP and DMS. Using a laboratory-based approach involving both semi-continuous batch cultures and chemostats, a series of incubation experiments will be conducted that mimic the extreme environmental conditions found within sea-ice. These experiments will reveal the stress physiology and cold adaptation of sea-ice diatoms. In parallel with the physiological analyses, a novel approach using proteomics tools, such as 2-D Difference Gel Electrophoresis will be used to determine which proteins are differentially expressed during acclimation to the environmental stressors. Artificial neural networks will assess the relationship between changes in DMSP production and changes in protein abundances, and find biomarker information on the pathways regulating cold acclimation, stress avoidance and DMSP production. Broader Impacts: At a global level, the proposed study would improve scientific understanding of what factors cause the high DMSP production in ice-algal communities and subsequently how DMSP production in sea ice diatoms could change as a result of global warming. As part of a high school outreach program, we will develop an interactive website to disseminate information on polar ecosystems and the role of the sulfur cycle in climate modulation. The proposed study will also provide support for a Ph.D. level student who will be directly involved in the proteomics component of the study and a Masters level student will be directly involved in the physiology component of the study. In addition, high school students involved in the outreach program and students from the REU program at the Grice Marine Laboratory (College of Charleston) will be offered opportunities to participate in the research effort.