Understanding Growth and Developmental Responses of Ectotherms to Fluctuating Environments: Beyond Performance Curves

了解生物体如何对波动的环境作出反应和适应是生物学家面临的主要挑战。生物体对当前环境条件的反应可以取决于它过去所经历的条件，由于压力（负面影响）或适应（积极影响）。生物学家目前缺乏一个框架来理解和量化这些影响：这个项目的目标是开发和测试这样一个框架，利用一个模型系统，烟草角虫（Manduca sexta）对变化温度的生长反应。该研究整合了生理实验、基因组学分析和数学模型，以预测压力和适应对生长、发育和生存的影响，并在不可预测的温度条件下测试这些预测。这一新的框架将有助于定量了解烟草角虫和其他农业害虫对天气变化的反应；一般框架应该适用于大多数其他“冷血”动物。该项目为本科生和研究生提供研究培训和经验，并开发了一项新的公民科学计划，用于监测北卡罗来纳州皮埃蒙特地区的蝴蝶和飞蛾。在一个单一的生命周期中，陆生变温动物经常经历温度和其他环境因素的巨大变化。个体的表现可以随着温度的变化而变化，表现为热表现曲线（TPC）， TPC是许多预测机体对温度波动反应的模型的基础。然而，许多变温动物表现出时间依赖性效应，包括应激反应和驯化，其中先前温度暴露的持续时间和顺序影响有机体性能；这些影响在标准TPC方法中被忽略。本文提出的研究开发并测试了一个将时间依赖效应纳入变温动物性能模型的新框架，以变温动物幼虫在波动温度下的生长速率为模型系统。这些研究整合了生理实验、功能基因组和蛋白质分析以及数学模型，以开发和参数化应激和驯化反应的系统建模框架，并测试该模型对昼夜温度波动随机变化的响应预测。该研究将为理解和预测温度和气候变化对变温动物生长和适合度的影响提供新的概念和模型框架基础。该项目为本科生和研究生提供研究培训和经验，并开发了一项新的公民科学计划，用于监测北卡罗来纳州皮埃蒙特地区的蝴蝶和飞蛾。

Understanding how organisms respond and adapt to fluctuating environments is a major challenge for biologists. The responses of an organism to current environmental conditions can depend on conditions it experienced in the past, due to either stress (negative effects) or acclimation (positive effects). Biologists currently lack a framework for understanding and quantifying those effects: the goal of this project is to develop and test such a framework, using the growth responses of a model system, the Tobacco Hornworm (Manduca sexta), to variable temperatures. The research integrates physiological experiments, genomics analyses and mathematical models to predict the consequences of stress and acclimation on growth, development and survival, and to test these predictions for unpredictable temperature conditions. This new framework will allow a quantitative understanding of responses of Tobacco Hornworms and other agricultural pests to variability in weather; the general framework should be applicable to most other 'cold-blooded' animals. The project provides research training and experience for undergraduate and graduate students, and develops a new citizen science program for monitoring butterflies and moths in the piedmont region of North Carolina.During the course of a single lifespan, terrestrial ectotherms often experience wide variation in temperature and other environmental factors. An individual's performance can vary with temperature, represented as a thermal performance curve (TPC), and TPCs are the basis for many models predicting organismal responses to fluctuating temperatures. However, many ectotherms exhibit time-dependent effects, including stress responses and acclimation, where the duration and order of prior temperature exposure affect organismal performance; these effects are ignored in the standard TPC approach. The studies proposed here develop and test a new framework for incorporating time-dependent effects into models of ectotherm performance, using growth rate of Manduca sexta larvae in fluctuating temperatures as a model system. The proposed studies integrate physiological experiments, functional genomic and protein analyses, and mathematical models to develop and parameterize a systems modeling framework for stress and acclimation responses, and test predictions from this model in response to stochastic variation in diurnal temperature fluctuations. The proposed research will provide the bases for a new conceptual and modeling framework for understanding and predicting the effects of variation in temperature and climate on growth and fitness of ectotherms. The project provides research training and experience for undergraduate and graduate students, and develops a new citizen science program for monitoring butterflies and moths in the piedmont region of North Carolina.