Gene Expression in Extreme Environments: Extending Microarray Technology to Understand Life at its Limits.

研究极端环境中的生命最具挑战性的要求之一是在现场研究生活在这些环境中的生物体，并了解生物生命的独特方面和生存所需的适应。南极海洋嗜冷菌为这项工作提供了一个极好的极端微生物模型组，因为人们对它们的生物和功能多样性或对零下1.8摄氏度生命的特定代谢适应知之甚少。这项研究的总体目标是开发基因组方法来研究直接从极端环境中采样的微生物，从而绕过培养要求。拟议工作的目标是(1)对直接从南极海洋嗜冷菌分离的六个大型细菌基因组DNA片段进行测序；(2)构建两种不同类型的DNA微阵列，旨在识别生活在南极零下海洋水域的未培养微生物中活跃表达的基因；(3)优化微阵列技术的特定方面，用于环境样本；以及(4)开发一种可移植的方法学，将有助于其他研究人员直接从自然环境获取基因表达信息。这项拟议的研究将利用南极基因组DNA文库，该文库由早期研究中创建的浮游古生菌和细菌DNA的大片段(40kb)组成，以开发靶向和鸟枪式DNA微阵列。DNA微阵列技术在极端环境下的生命研究中的应用为鉴定用于生物技术的新基因提供了一个绝佳的机会。通过检测在自然环境中唯一表达的基因来发现对极端环境的特定适应是这项研究的最终目标。

One of the most challenging requirements for the study of life in extreme environments is studying the organisms inhabiting these environments in situ, and understanding the unique aspects of biological life and adaptations required for survival. The Antarctic marine psychrophiles provide an excellent model group of extreme microorganisms for this work, since very little is known about their biological and functional diversity, or specific metabolic adaptations to life at -1.8 degree C. The overall goal of this research is the development of genomic approaches for studying microorganisms sampled directly from extreme environments and thus, circumventing the requirement for cultivation. The objectives of the proposed work are (1) to sequence six large bacterial genomic DNA fragments isolated directly from Antarctic marine psychrophiles; (2) to construct two different types of DNA microarrays designed to identify genes being actively expressed in uncultivated microorganisms living in the sub-zero marine waters of the Antarctic; (3) to optimize specific aspects of microarray technology for use with environmental samples; and 4) to develop a transferable methodology that will be useful for other researchers in accessing gene expression information directly from the natural environment. The proposed study will make use of an Antarctic genomic DNA library comprised of large (40 kb) genomic fragments of planktonic archaeal and bacterial DNA created in earlier studies to develop targeted and shotgun DNA microarrays. The application of DNA microarray technology to studies of life in extreme environments offers an outstanding opportunity for identifying new genes for biotechnological use. Discovering specific adaptations to extreme environments by detecting genes that are uniquely expressed in the natural environment is an ultimate goal of the research.