COLLABORATIVE RESEARCH: Ecological and Evolutionary Physiology of the Stress Response and Stress Proteins

生态学和进化生理学的一个主要问题是复杂生物的特征、生物利用不同环境的能力和物种在时间上的持久性之间的关系。本研究在一定程度上使用果蝇热休克蛋白Hsp70作为模型性状/生物/系统来解决这一问题。在对热或其他胁迫的反应中，几乎所有的生物都表达热休克蛋白（I-Isps），这是一种高度保守的蛋白，通过充当分子伴侣来促进应激耐受性。先前由NSF资助的研究已经证实，对编码Hsp70的果蝇Hsp70基因拷贝数的实验操纵足以引起自然热应激下的直接生存变化，并且自然种群中Hsp70表达的变化与它的适应性相一致。拟议的研究将建立在最近一个重要的初步发现的基础上：热休克蛋白70不仅可以防止热死亡，还可以减轻在成虫前阶段经历自然热应激的成虫翅膀和腹部的主要形态异常。这种形态异常可能发生在10%的存活成虫身上，并可能损害求偶和交配、领土防御、产卵、飞行和水分平衡，这些都可能是健康的组成部分。拟议的研究将首先将这些异常的发生率与非成年果蝇在实验室中经历的温度联系起来，然后验证自然界中果蝇也存在类似的关系。接下来，我们将研究这些异常对求爱和交配、领土防御、产卵、飞行和水分平衡的影响。最后，本实验将通过基因和实验操作热休克蛋白的表达，以确定热休克蛋白70在保护或减轻形态学缺陷中的作用。该研究的预期结果具有巨大的潜力，可以整合分子、遗传、功能和进化的观点，以促进对适应的理解。

A major issue in ecological and evolutionary physiology is the relationship among the traits of complex organisms, organisms' ability to exploit diverse environments, and species' persistence in time. The proposed investigation in part uses the heat-shock protein Hsp70 in Drosophila as a model trait/organism/system to address this issue. In response to heat or other stresses, nearly all organisms express heat-shock proteins (I-Isps), highly-conserved proteins that contribute to stress tolerance by functioning as molecular chaperones. Research supported by previous NSF awards has established that experimental manipulation of copy number of the hsp7O gene of Drosophila, which encodes Hsp7O, is sufficient to cause changes in outright survival of natural thermal stress, and that natural populations vary in Hsp70 expression in ways that are consistent with it being adaptive. The proposed research will build upon a recent and significant preliminary finding: that not only does Hsp70 protect against heat death, it also mitigates major morphological anomalies in wings and abdomens of adults that have undergone exposure to natural thermal stress during their pre-adult stages. Such morphological abnormalities can occur in 10% of surviving adults and potentially compromise courtship and mating, territorial defense, oviposition, flight, and water balance, each a likely component of fitness. The proposed research will first relate the incidence of these abnormalities to the temperatures that non-adult Drosophila undergo in the laboratory, and then verify that similar relationships occur for Drosophila in nature. Next, the proposed research will establish the effect of these abnormalities on courtship and mating, territorial defense, oviposition, flight, and water balance. Finally, the proposed experiment will genetically and experimentally manipulate Hsp expression to establish the role of Hsp7O in protecting or mitigating morphological defects. The projected outcome of the proposed research has immense potential to integrate molecular, genetic, functional, and evolutionary perspectives to advance understanding of adaptation.