Investigating mechanisms and costs of increased temperature variation in tropical and temperate dung beetles

温度深刻地影响着动物的生理，因此温度波动对物种的生存和繁殖具有重大影响。与在温带等温度多变的环境中进化的动物相比，在热带等相对恒定的热环境中进化的动物，温度波动可能尤其具有挑战性。为了了解温度波动如何影响来自不同热环境的物种，该项目将使热带和温带屎甲虫暴露在温度波动增加的环境中，并整合不同生物组织水平的数据。具体地说，研究人员将量化热带和温带屎甲虫的基因表达和对温度波动升高的生理反应，然后调查物种反应如何影响生存和繁殖。这项工作的结果将有助于更好地了解不同纬度动物对环境挑战的敏感性。这项研究的更广泛影响包括在美国和国际现场对研究生和本科生进行生理学和生态学方面的培训，从而加强学生的全球网络。为了向公众传达研究成果，该团队将使用YouTube频道，发布非科学家可以访问的研究视频。团队成员将继续在田纳西大学主持一年一度的落基顶峰生物闪电战，帮助公民了解城市环境中的生物多样性。最后，这项研究将把昆虫标本添加到美国和厄瓜多尔的收藏品中，用于教学和研究。理论预测，温度波动应该比平均温度的变化对生理和健康产生更大的影响，这些影响应该随着生物体的进化史而变化。该项目应用热带和温带屎甲虫的转录和生理数据，以改变目前对纬度相隔的物种因温度波动增加而产生的能量反应和适应成本的理解。具体地说，研究人员将测量基因表达和生理(即代谢率)对温度波动增加的反应。然后将量化增加的热波动的能量后果。最后，将评估与体能相关的变量对温度波动的响应。该项目将有助于更好地理解分配给应激反应的能量与分配给繁殖的能量之间的权衡，为更现实地建立跨纬度温度波动影响的模型奠定基础，该模型可以在其他物种上复制。此外，这项研究将提供热带物种和非模式生物分子机制的关键信息。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Temperature profoundly impacts animal physiology, thus temperature fluctuations has major consequences for survival and reproduction of species. Temperature fluctuations may be particularly challenging for animals that have evolved in relatively constant thermal environments, like tropical regions, compared to those that have evolved in thermally variable environments, like temperate regions. To understand how temperature fluctuations affect species from different thermal environments, this project will expose tropical and temperate dung beetles to increased temperature fluctuations and integrate data across levels of biological organization. Specifically, the researchers will quantify gene expression and physiological responses of tropical and temperate dung beetles to increases in temperature fluctuation and then investigate how species responses affect survival and reproduction. The results of this work will support a greater understanding of sensitivity of animals from different latitudes to environmental challenges. Broader impacts of the research include training of graduate and undergraduate students in physiology and ecology in the USA and at international field sites, thus strengthening the students' global networks. To communicate research to the public, the team will use a YouTube channel, to post research videos that are accessible to non-scientists. Team members will continue to host the annual Rocky Top BioBlitz at the University of Tennessee to help citizens learn about biodiversity in urban environments. Lastly, the research will add insect specimens to collections in the USA and Ecuador for teaching and research. Theory predicts that temperature fluctuations should have greater impacts on physiology and fitness than shifts in mean temperature alone, and these impacts should vary with the evolutionary history of the organism. This project applies transcriptomic and physiological data from tropical and temperate dung beetles to transform current understanding of energetic responses and fitness costs associated with increased temperature fluctuations for species separated by latitude. Specifically, the researchers will measure gene expression and physiological (i.e. metabolic rate) responses to increased temperature fluctuations. Energetic consequences of increased thermal fluctuations will then be quantified. Finally, fitness-related variables in response to increased temperature fluctuations will be evaluated. This project will lead to a better understanding of trade-offs between energy allocated to stress responses versus energy allocated to reproduction, providing a foundation for a more realistic model of the impacts of temperature fluctuations across latitude that can be replicated for other species. In addition, the research will provide key information on molecular mechanisms in tropical species and non-model organisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.