Collaborative Research: Physiological and Genetic Responses to Winter in a Willow Leaf Beetle

在内华达州山脉，像许多高海拔环境一样，积雪每年都有很大的变化。许多高海拔的动物在雪下过冬，雪为它们提供了抵御极端温度的缓冲。许多独特的和生态上重要的动物生活在山区环境中，这使得了解和预测积雪的年度差异对其种群丰度的影响至关重要，但到目前为止，我们对雪如何影响昆虫和其他动物的生存和繁殖的了解有限。该项目建议在实验室和自然环境中研究高海拔甲虫对积雪变化的生理和遗传反应，以了解雪如何改变冬季和随后的夏季的繁殖成功。 这项工作将发展加州大学伯克利分校和两个小学本科院校之间的伙伴关系。在Priestival本科院校的本科生将与来自伯克利的研究人员合作，伯克利博士生将监督来自各种背景和经验的本科生。因此，这两类学生将接触到不同教育机构的文化，并有机会接触到他们通常网络之外的专业联系人。该项目为K-12学生开发的课程模块将用于帮助他们了解生物体在多雪气候中面临的挑战，该模块将通过加州大学伯克利分校的网站分发给K-12教师。为了抵御冬季寒冷，高海拔昆虫使用能量储存来合成代谢昂贵的冷冻保护剂。这可能会在抗寒性和节能之间产生权衡。雪缓冲热波动，降低冷死亡率和抗寒性的需要。 然而，由于雪下的温度高于无雪的裸露栖息地，因此可能会增加与雪下生活相关的整体能源需求。 由于能量的权衡，冬季积雪和气温的年际波动将改变越冬生物的选择压力，并可能显着影响夏季的生长和繁殖。核心假设是，积雪的变化改变了抗寒性和能量守恒的选择压力，影响越冬个体的生理表现和幸存者的遗传组成。研究人员进一步假设，抗寒性通过消耗冬季能量储备来抵消未来的繁殖，这是由于抗寒性的能量成本。该研究将：1）测量雪的变化如何改变高海拔甲虫冬季相关遗传变异的选择梯度，并分离冬季选择梯度的因果驱动因素。2)获得对寒冷和能量压力如何相互作用以塑造冬季和随后的夏季生理表现的预测和定量了解。3)通过询问单一或组合的应激源如何改变能量储备和冷冻保护剂的反应规范，揭示冷和能量应激之间相互作用的潜在机制。

In the Sierra Nevada mountain ranges, like many high altitude environments, snow cover is extremely variable from year to year. Many high altitude animals survive through winter underneath snow that buffers them from extremes of temperature. Many unique and ecologically important animals live in mountainous environments, making it vital to understand and predict impacts of annual differences in snow cover on their population abundances, but as yet we have limited understanding of how snow impacts survival and reproduction of insects and other animals. This project proposes to study physiological and genetic responses to variation in snow cover in a high altitude beetle in the laboratory and the natural environment to understand how snow alters reproductive success during the winter and subsequent summer. This work will develop a partnership between UC-Berkeley and two Primarily Undergraduate Institutions. Undergraduates at the Primarily Undergraduate Institutions will work with researchers from Berkeley, and Berkeley PhD students will supervise undergraduates from a wide variety of backgrounds and experiences. Thus both groups of students will be exposed to the culture of different educational institutions and will have access to professional contacts outside their usual network. A curriculum module developed from the project for K-12 students will be used to contribute towards their understanding of challenges that organisms face in snowy climates, and this module will be distributed to K-12 teachers through a UC Berkeley-based website.For high altitude animals, summer is a time of energy gain, while energy conservation is key during winter because resources are scarce and animals rely on energy stores. To resist winter cold, high altitude insects use energy stores to synthesize metabolically expensive cryoprotectants. This may generate a trade-off between cold hardiness and energy conservation. Snow buffers thermal fluctuations, decreasing cold mortality and need for cold hardiness. However, since temperatures are greater beneath snow than in a snow-free, exposed habitat, there may be increased overall energy demand associated with living under snow. Due to the energetic trade-off, inter-annual fluctuations in winter snowpack and air temperature will alter selective pressures on overwintering organisms, and may significantly affect growth and reproduction in summer. The central hypothesis is that variation in snow cover alters selective pressures on cold hardiness and energy conservation, influencing physiological performance of overwintering individuals and genetic composition of survivors. The investigators further hypothesize that cold hardiness trades off against future reproduction by depleting winter energy reserves due to energetic costs of cold hardiness. The research will: 1) Measure how variation in snow alters selective gradients on winter-relevant genetic variation in a high altitude beetle, and isolate causal drivers of winter selective gradients. 2) Gain a predictive and quantitative understanding of how cold and energy stressors interact to shape physiological performance during winter and the subsequent summer. 3) Uncover mechanisms underlying interactions between cold and energy stress by asking how single or combined stressors alter reaction norms for energy reserves and cryoprotectants.