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

合作研究：柳叶甲虫对冬季的生理和遗传反应

• 批准号: 1557513
• 负责人: Elizabeth Dahlhoff
• 金额: $ 4.74万
• 依托单位: Santa Clara University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1557513&HistoricalAwards=false
• 关键词: Collaborative; Research; Physiological; Genetic; Responses

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.

在内华达山脉的山脉中，像许多高海拔环境一样，雪覆盖的年度极大变化。许多高海拔的动物在冬天的雪下生存，从而使它们摆脱了极端温度。许多独特且重要的动物生活在山区环境中，使理解和预测雪覆盖年度差异对其人口丰度的影响至关重要，但是到目前为止，我们对降雪如何影响昆虫和其他动物的生存和繁殖有限。该项目建议研究实验室和自然环境中高海拔甲虫中雪覆盖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生殖成功。 这项工作将在加州大学伯克利分校和两个主要是本科机构之间建立合作伙伴关系。主要是本科机构的本科生将与伯克利的研究人员合作，伯克利博士生将监督各种背景和经验的本科生。因此，两组学生都将接触到不同教育机构的文化，并可以在其通常的网络之外获得专业联系。该项目为K-12学生开发的课程模块将有助于他们对生物体在雪环境中面临的挑战的理解，并且该模块将通过基于UC Berkeley的网站分发给K-12老师。对于高海拔的动物而言，夏季能量保存是一个关键的夏季，而能源保存在冬季是关键的，因为资源是稀缺的动物，因为稀缺的动物依赖能量储存。为了抵抗冬季寒冷，高海拔昆虫使用能量储存来合成代谢昂贵的冷冻保护剂。这可能会产生冷野性和节能之间的权衡。积雪缓冲热波动，降低冷死亡率并需要冷耐用性。 但是，由于在雪下的温度比在无雪，裸露的栖息地中更高，因此与雪下生活有关的总能量需求可能会增加。 由于精力折算，冬季积雪和空气温度的年度波动将改变越冬的生物的选择压力，并且可能会严重影响夏季的生长和繁殖。中心假设是，雪的变化覆盖了对冷坚硬和节能的选择性压力，影响了越冬个体的生理表现和幸存者的遗传组成。调查人员进一步假设，由于冷顽固性的有力成本，冬季能量储量耗尽，冷野性与未来的繁殖相抵触。研究将：1）测量雪的变化如何改变高海拔甲虫中冬季相关的遗传变异的选择性梯度，以及分离冬季选择性梯度的因果驱动因素。 2）对冷应力和能量压力的相互作用如何在冬季和随后的夏季塑造生理表现方面获得预测性和定量理解。 3）通过询问单个应力或组合应力源如何改变能量储量和冷冻保护剂的反应规范，从而发现冷应力和能量应力之间相互作用的机制。