Collaborative Research: A Proteomic approach to understanding cytoprotective biogenic sulfur production in sea-ice diatoms.

知识价值：生物硫化合物，如二甲硫醚（DMS）及其前体二甲基磺酰丙酸酯（DMSP），由于其对地球辐射预算的影响，是具有重要气候意义的化合物。海冰藻类群落是DMSP和DMS的重要生产者，矛盾的是，这些群落通常也由硅藻主导，硅藻在远洋环境中产生微不足道的DMSP和DMS。将采用以实验室为基础的方法，包括半连续批培养和恒化剂，进行一系列模拟海冰内极端环境条件的孵化实验。这些实验将揭示海冰硅藻的胁迫生理和冷适应。在生理分析的同时，一种使用蛋白质组学工具的新方法，如二维差异凝胶电泳，将被用来确定哪些蛋白质在适应环境压力时存在差异表达。人工神经网络将评估DMSP产生变化与蛋白质丰度变化之间的关系，并找到调节冷驯化、应激避免和DMSP产生的途径的生物标志物信息。更广泛的影响：在全球范围内，拟议的研究将提高对导致冰藻群落中DMSP高产量的因素的科学理解，以及随后海冰硅藻中DMSP产量如何因全球变暖而变化。作为高中外展计划的一部分，我们将开发一个互动网站，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级别的学生提供支持，他们将直接参与研究的蛋白质组学部分，硕士级别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来自Grice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.