Endocrine, genetic and epigenetic mechanisms of coping with environmental change in tropical birds

生物如何科普环境中的不确定性？了解生物体如何在生理上科普自然变化的环境，对于预测生物体（包括人类）对日益不可预测的环境（以干旱和洪水等频繁的极端天气事件为特征）的反应至关重要。由于应对机制本身，短期的生理和行为反应，在较长的时间内对环境变化做出反应，因此需要一种比较方法来充分了解生物体在历史上如何应对气候的不确定性。为了确定脊椎动物如何在生理和分子水平上适应和科普环境变化，本研究将同时探索肯尼亚生态梯度中鸟类基因的遗传和表观遗传变异模式，这些基因是压力反应和整个基因组的基础，然后将这种变异与自然变化和实验控制的气候中的基因表达模式联系起来。本研究将在实地和实验室培训高中生、本科生和研究生，特别是那些来自代表性不足群体的学生。培训将强调可跨学科转移的尖端综合工具。研究人员将与肯尼亚的一个基层保护组织密切合作，通过一系列教学模块和公开陈述，教育农村学童了解保护和野生动物。最后，研究人员将在纽约市当地和针对不同受众的流行文章中展示他们的工作成果。脊椎动物在生理上科普环境变化的主要方式之一是通过下丘脑-垂体-肾上腺（HPA）轴的变化，HPA轴是控制对压力反应的神经内分泌系统。HPA轴包括一系列激素、受体和其他分子，每一种都可能对不同类型和时间尺度的环境变化做出反应。虽然了解HPA轴如何响应环境变化对于确定生物体如何科普环境不确定性非常重要，因为它是脊椎动物响应环境压力的第一种方式之一，但许多其他生理，内分泌和分子途径也受到环境压力的影响。因此，将分子机制和适应性遗传和表观遗传变异更广泛地与生理功能联系起来的全基因组方法对于了解动物如何适应和科普环境的不确定性是必要的。本研究的目的是确定环境变化如何影响适应性遗传（DNA序列）和表观遗传变异（DNA甲基化），基因功能（mRNA表达），和生理反应（激素活性）在自由生活的华丽椋鸟种群中形成特定的表型（Lamprotornis superbus）在亚热带的大尺度生态梯度上取样，撒哈拉非洲包括世界上一些最不可预测的气候带。建立在非洲椋鸟的长期数据，并使用一系列新建立的种群沿着肯尼亚的生态梯度，这项工作将使研究人员开始了解环境诱导的选择压力如何塑造的分子机制，适应性进化反应，以及应对策略，脊椎动物使用的生活与环境的不确定性。

How do organisms cope with uncertainty in their environment? Understanding how organisms cope physiologically with naturally variable environments will be important for predicting organismal responses, including those in humans, to increasingly unpredictable environments characterized by frequent extreme weather events like droughts and floods. And since coping mechanisms themselves, short-term physiological and behavioral responses, respond to environmental variation over longer time periods, a comparative approach is needed to fully understand how organisms have historically responded to climatic uncertainty. To determine how vertebrates adapt to and cope with environmental variation at the physiological and molecular level, this study will simultaneously explore patterns of genetic and epigenetic variation in genes of birds that underlie the stress response and the entire genome across an ecological gradient in Kenya, and then relate this variation to patterns of gene expression in naturally variable and experimentally-controlled climates. This study will train high school students, undergraduates, and graduate students, particularly those from underrepresented groups, in the field and lab. Training will emphasize cutting-edge, integrative tools that are transferable across disciplines. Researchers will work closely with a grassroots Kenyan conservation organization to educate rural schoolchildren on conservation and wildlife through a series of teaching modules and public representations. Finally, researchers will present the results of their work locally around New York City and in popular articles aimed at a diverse audience.One of the primary ways that vertebrates cope physiologically with environmental variability is through changes in the hypothalamo-pituitary-adrenal (HPA) axis, the neuroendocrine system that controls reactions to stress. The HPA axis encompasses a cascade of hormones, receptors, and other molecules, each of which may respond to different types and timescales of environmental variation. Although understanding how the HPA axis responds to environmental variability is important for determining how organisms will cope with environmental uncertainty because it is one of the first ways that vertebrates respond to environmental stressors, many other physiological, endocrine, and molecular pathways are also impacted by environmental stressors. Therefore, a genome-wide approach that links molecular mechanisms and adaptive genetic and epigenetic variation more broadly to physiological function will be necessary to understand how animals adapt to and cope with environmental uncertainty. The objective of this study is to determine how environmental variation influences adaptive genetic (DNA sequence) and epigenetic variation (DNA methylation), gene function (mRNA expression), and physiological responses (hormone activity) to shape particular phenotypes in populations of free-living superb starlings (Lamprotornis superbus) sampled across a broad-scale ecological gradient in sub-Saharan Africa encompassing some of the most unpredictable climatic zones in the world. Building upon long-term data in African starlings, and using a series of newly-established populations along an ecological gradient in Kenya, this work will allow researchers to begin to understand how environmentally-induced selection pressures shape the molecular mechanisms, adaptive evolutionary responses, and coping strategies that vertebrates use to live with environmental uncertainty.