Ecological and Evolutionary Physiology of the Stress Response and Stress Proteins

基因的进化对于细菌获得耐药性、影响人类健康的病毒以及物种对全球气候变化的敏感性等多种重要现象至关重要。决定基因突变的因素——基因进化的第一步——人们对其了解甚少。这项研究将在美国国家科学基金会支持的一项发现的基础上进行，该发现发现，一类被称为热休克基因的基因对突变特别敏感，因为转座因子（能够从一个基因跳到另一个基因的DNA序列）很容易侵入普通果蝇（Drosophila melanogaster）自然种群中的这些基因。如果这种现象及其意义确实是普遍的，那么它应该在许多物种中发现。第一个目标将是使用计算机技术在许多物种的热休克基因中搜索转座因子，这些物种的基因组现在已经测序并可在网上获得。第二个目标是寻找另一种果蝇（Drosophla willistoni）热休克基因中的转座因子。美国国家科学基金会支持的研究表明，如果转座因子存在，它们会影响宿主基因的功能。在自然种群中，转座因子可以插入不同的位置和大小，有时多个因子可以出现在一个基因中。第三个目标将是了解这种变异对基因制造蛋白质的方式的影响，以及蛋白质的变化如何影响对压力、生长和繁殖的耐受性。因此，这项研究可以解释一个物种对环境变化的反应能力。这个项目还将成为培训年轻科学家、教育其他国家的科学家以及提供其他科学家可以利用的信息的工具。

The evolution of genes is critical for such diverse and important phenomena as bacteria acquiring resistance to drugs, viruses affecting human health, and species' sensitivity to global climate change. Factors determining how readily genes mutate - the first step in their evolution - are poorly understood. This research will follow up on an NSF-supported discovery that one class of genes, named heat-shock genes, are especially sensitive to mutation because transposable elements (DNA sequences capable of jumping from gene to gene) readily invade these genes in natural populations of the common fruit fly, Drosophila melanogaster. If this phenomenon and its significance are truly general, it should be found in many species. A first goal will be to use computer techniques to search for transposable elements in the heat-shock genes of many species whose genomes have now been sequenced and are available online. A second goal will be to search for transposable elements in the heat-shock genes of a different fruit fly species, Drosophla willistoni. As NSF-supported research has shown, if transposable elements are present they can affect the way the host gene functions. In natural populations, the transposable elements can insert in different places and be of different sizes, and sometimes multiple elements can be present in a single gene. A third goal will be to understand the consequences of such variation for the way the genes make proteins, and how changes in the proteins affect tolerance of stress, growth, and reproduction. Thus, this research may explain a species' ability to respond to environmental change. This project will also serve as a vehicle for training young scientists, educating scientists in other countries, and providing information on which other scientists can build.