RUI Collaborative Proposal: Biochemical and Physiological Mechanisms of Thermal Adaptation in a Montane Insect Herbivore

本研究调查了叶甲叶甲在高海拔种群中的进化。内华达山脉(加利福尼亚州)的种群处于该物种范围的南部边缘。以前的研究发现，排水系统的气温不同，甲虫的数量随着气候的变化而波动。温度敏感酶磷酸葡萄糖异构酶(PGI)的不同形式(基因型)的频率在不同的排水系统中不同，这表明自然选择对PGI起作用。甲虫体内的热休克蛋白(HSP)水平与气温差异相对应，并受PGI基因的影响。这项拟议的研究将调查温度与PGI基因类型的功能特性(即它们催化新陈代谢基本的生化反应的能力)之间的关系。其次，以热休克蛋白和泛素结合物作为生理胁迫指标，研究温度对不同PGI基因型甲虫生理的影响。第三，比较自然界中不同PGI基因的甲虫的存活和繁殖情况。这项研究将为酶基因多态的进化意义提供重要信息。它可能会增加对气候变化对本土昆虫影响的洞察。最后，它将允许本科生参与基础研究，增强他们的教育经验，扩大他们未来的机会

This research investigates evolution in high elevation populations of the leaf beetle Chrysomela aeneicollis. Populations in the Sierra Nevada (California) are on the southern edge of the species' range. Previous studies found that drainages differ in air temperature and beetle populations fluctuate with changes in climate. Frequencies of different forms (genotypes) of the temperature-sensitive enzyme phosphoglucose isomerase (PGI) vary among drainages, suggesting that natural selection acts on PGI. Heat shock protein (Hsp) levels in beetles correspond to air temperature differences and depend on PGI genotype. The proposed research will investigate the relationship between temperature and functional property of PGI genotypes (i.e. their ability to catalyze biochemical reactions fundamental to metabolism). Second, the effects of temperature on the physiology of beetles of different PGI genotype will be studied, using Hsp's and ubiquitin conjugates as indices of physiological stress. Third, survival and reproduction of beetles of different PGI genotype in nature will be compared. The research will provide important information about the evolutionary significance of enzyme polymorphisms. It may add insight about the impact of climate change on native insects. Finally, it will allow undergraduates to participate in basic research, enhance their educational experience and expand their opportunities for the future