DISSERTATION RESEARCH: Evolutionary Physiology of Heat-Shock Gene Expression

论文研究：热休克基因实验的进化生理学。Martin E. Feder丹尼尔Lerman拟议的研究将调查一个值得注意的案例，其中转座因子（TE，能够在基因组内从一个地方移动到另一个地方的DNA片段）反复但独立地破坏编码诱导型分子伴侣（一种防止或减轻对其他蛋白质的损害的蛋白质;例如，Hsp 70]，这反过来又会影响环境压力和健身的耐受性。 这个系统有很大的希望，作为一个模型，调查如何大规模的生理性状差异产生的微小变化群体内的个人之间。先前的研究已经发现了3个独立的例子，其中，在果蝇果蝇的自然种群中，TE插入破坏了热休克反应元件之间的间距在热休克70 Ba近端启动子;每个这样的人口表现出独特的热休克70蛋白水平。对于每个种群，拟议的研究将开发复制系，以：（1）定量Hsp 70蛋白水平，以测试具有TE破坏的启动子的果蝇是否表达较少的Hsp 70;（2）确定TE驱动的Hsp 70表达差异是否影响诱导型热耐受性，这是Hsp 70的主要生物体水平表型;（3）通过特异性核糖核酸酶保护测定，确定TE是否破坏Hsp 70的反式激活[Hsp 70编码基因的转录];（4）测量hsp 70 Ba启动子的TE破坏是否如预测的那样增强未经历热应激的果蝇中的适应性。拟议的研究将整合分子遗传学，生物化学和生理学方法，并率先阐明种群内调控序列变异和表型多样化之间的联系。

Dissertation Research: Evolutionary Physiology of Heat-Shock Gene ExperessionDr. Martin E. Feder & Daniel LermanThe proposed research will investigate a remarkable case in which transposable elements [TEs, pieces of DNA that have the ability to move from one place to another within the genome] have repeatedly but independently disrupted the promoter [region controlling transcription] of a gene encoding an inducible molecular chaperone [a protein that prevents or alleviates damage to other proteins; e.g., Hsp70], which in turn should affect tolerance of environmental stress and fitness. This system has great promise as a model for investigating how large-scale differences in physiological traits arise from minor variation among individuals within populations. Prior research has discovered 3 independent instances in which, in natural populations of the fruit fly Drosophila, TE insertions disrupt the spacing between heat-shock response elements in the hsp70Ba proximal promoter; each such population exhibits distinctive Hsp70 protein levels. For each population, the proposed research will develop replicate lines with which to: (1) Quantify Hsp70 protein levels to test whether flies with TE-disrupted promoters express less Hsp70; (2) Determine whether TE-driven differences in Hsp70 expression affect inducible thermotolerance, a principle organism-level phenotype of Hsp70; (3) Determine, via specific ribonuclease protection assays, whether the TEs disrupt hsp70 transactivation [transcription of the Hsp70-encoding gene]; (4) Measure whether, as predicted, TE-disruption of the hsp70Ba promoter enhances fitness in Drosophila not undergoing heat stress. The proposed research will integrate molecular genetic, biochemical and physiological approaches, and be among the first to elucidate the link between intrapopulation regulatory sequence variation and phenotypic diversification.