International Research Fellowship Program: Profiling Marine Herbivore Gene Expression in Response to Algal Chemical Defenses

国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。Whalen，加州大学圣巴巴拉分校，与澳大利亚南威尔士大学的Peter Steinberg博士和圣巴巴拉的加州大学的Gretchen Hofmann博士合作。分子工具和传统方法的结合为海洋藻类-草食动物相互作用的研究带来了化学生态学领域的巨大希望。 尽管在确定藻类化学防御的多样性，浓度和分布及其对海洋食草动物的影响方面取得了巨大进展，但很少有研究涉及这些食草动物对其化学防御食物的耐受性差异的近端机制。 部分问题是我们几乎没有关于海洋食草动物介导这种相互作用的生理反应的信息。 幸运的是，基因组技术的最新进展将为细胞和最终生物体如何耐受和应对环境化学应激提供详细和前所未有的机制基础。 使用DNA微阵列的转录组分析等技术将允许对数千个基因的表达进行平行分析，并提供对饮食化合物反应中发生的基因调控的完整图片。 随着最近完成和注释的紫海胆基因组，基因负责介导耐藻类化学，可以，第一次，在海洋食草动物中被确定。 该项目的中心目标是开发海胆微阵列作为了解海洋食草动物生理学和对饮食化学应激源的抗性的更广泛方面的工具。 寡核苷酸阵列将被设计和构建，靶向2000多个重要的基因，在异生物质解毒/外排，信号转导，营养代谢和化学感受。 这种定制设计的海胆阵列将用于分析澳大利亚海胆Heliocidaris erythrogramma的基因表达，以应对化学多样性的大型藻类饮食。 转录组分析将鉴定靶基因，其时间表达将通过实时定量PCR进一步评估。 此外，通过转录组分析鉴定的基因可以作为藻类化合物-蛋白质相互作用的额外生化表征的目标。PI预计这项工作将增加我们对影响藻类-草食动物相互作用的潜在生化机制的了解，从而更全面地了解海洋消费者对饮食化学应激源的反应和饮食选择的生化基础。

0754319WhalenThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four month research fellowship by Dr. Kristen E. Whalen, University of California, Santa Barbara, to work with Dr. Peter Steinberg at the University of South Wales in Australia, and with Dr. Gretchen Hofmann at the University of California, Santa Barbara.The marriage between molecular tools and traditional methods for the study of marine algal-herbivore interactions holds considerable promise for the field of chemical ecology. Despite tremendous progress in identifying the diversity, concentrations and distribution of algal chemical defenses and their impact on marine herbivores, few studies have addressed the proximate mechanisms underlying the profound variation in tolerance among these herbivores for their chemically defended foods. Part of the problem is we have virtually no information on the physiological responses of marine herbivores mediating this interaction. Fortunately, recent advances in genomic technology will provide a detailed and unprecedented view of the mechanistic underpinnings of how cells and ultimately organisms tolerate and respond to environmental chemical stresses. Techniques such as transcriptome profiling using DNA microarrays will allow for the parallel analysis of the expression of thousands of genes and provide a complete picture of gene regulation occurring in response to dietary compounds. With the recent completion and annotation of the purple sea urchin genome, genes responsible for mediating tolerance of algal chemistry can, for the first time, be identified in a marine herbivore. The central objective of this project is to develop the sea urchin microarray as a tool for understanding broader aspects of marine herbivore physiology and resistance to dietary chemical stressors. An oligonucleotide array will be designed and constructed targeting over 2000 genes important in xenobiotic detoxification/efflux, signal transduction, nutrient metabolism and chemoreception. This custom designed sea urchin array will be used to profile gene expression in the Australian urchin Heliocidaris erythrogramma, in response to chemically diverse macroalgal diets. Transcriptome profiling will identify target genes whose temporal expression will be further assessed by real-time quantitative PCR. Furthermore, genes identified by transcriptome profiling can be targeted for additional biochemical characterization of algal compound-protein interactions. The PI anticipates this work will add volumes to our knowledge of the underlying biochemical mechanisms influencing algal-herbivore interactions, leading to a more complete understanding of marine consumer response to dietary chemical stressors and the biochemical basis of diet selection.