NSF-BSF: Stress tolerance: Inheritance and regulation by diverse epigenetic mechanisms

该项目旨在确定早期（胚胎）环境的变化如何对鸡的新陈代谢和应激反应产生终生影响，并从父母传递给后代。研究人员将在血液和大脑中研究温度胁迫下生理弹性遗传的表观遗传变化，并确定这些变化是如何遗传和调节的。这项工作挑战了DNA上的表观遗传标记在受精时被删除和重建的范式，并表明在发育的关键阶段的环境扰动可能对后代和后代产生持久的影响。这项研究为理解不涉及DNA核苷酸序列变化的遗传行为的机制提供了一个框架。鸡是这项研究的理想模型，因为鸡蛋可以在严格控制的环境条件下大量孵化，而且没有父母的参与消除了对发育的潜在混淆影响。本研究的主题是生理弹性，这与更广泛的影响的主题是平行的：具有挑战性的环境中的专业弹性。目标成果是加强来自代表性不足群体的学生参与STEM研究。小鸡是一个理想的研究模型纳入课堂，因为相对较低的成本和时间的投资，以产生数据和完成实验。弗吉尼亚理工大学与以色列波尔尼研究所之间的合作通过展示多样性和国际研究合作的重要性，有助于取得成果。胚胎环境对以后的生理功能有长期的影响。胚胎热调节诱导免疫和代谢系统内的终身（和跨代）热恢复和交叉耐受性（即改善其他系统的健康）。表观遗传标记负责应激反应的跨代传递，挑战了表观遗传修饰在受精时在生殖细胞中被消除的假设。其中一些变化被保留下来并传给了后代。表观遗传修饰将在三代鸡中进行，从卵（胚胎）热调节，到终生遇到环境挑战，受精，原始生殖细胞，以及连续两代的正常生长。将在血液和负责调节这些通路的大脑区域（包括下丘脑视前区和下丘脑室旁核）中研究与应激、代谢和炎症相关的通路。表观遗传机制包括DNA甲基化和与组蛋白修饰的相互作用，以及表转录组标记，这些将使用全局（通过测序）和位点特异性（通过核酸和蛋白质相互作用）方法进行评估。这项工作将在美国弗吉尼亚理工大学和以色列波尔尼研究所同时进行，对来自不同地理位置的不同遗传背景的鸡提供可靠的结果。该项目将作为一个平台，招募来自代表性不足背景的学生进行研究，并将每年培训一名研究生研究员。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project seeks to determine how changes in the early-life (embryonic) environment cause lifelong effects on metabolism and stress responses that are passed on from parents to offspring in chickens. The epigenetic changes that are responsible for inheritance of physiological resilience in response to temperature stress will be studied in the blood and brain, and it will be determined how these changes are inherited and how they are regulated. This work challenges the paradigm that epigenetic marks on the DNA are erased and reestablished at fertilization and suggests that environmental perturbations during critical stages of development can have lasting effects on the offspring and later generations. This research provides a framework for understanding the mechanisms involved in heritable behaviors that do not involve changes to the DNA nucleotide sequence. The chicken is an ideal model for this research, because eggs can be incubated in large numbers under tightly controlled environmental conditions, and the lack of parental involvement eliminates potential confounding effects on development. The major theme of this research is physiological resilience, which parallels the theme of the broader impacts: professional resilience in a challenging environment. The targeted outcomes are to enhance involvement of students from underrepresented groups in STEM research. The chick is an ideal research model to incorporate into the classroom because of the relative low cost and time investment for generating data and completing experiments. The collaboration between Virginia Tech and the Volcani Institute in Israel contributes to outcomes by demonstrating the importance of diversity and international cooperation in research. The embryonic environment has long-term effects on physiological functions later in life. Embryonic heat conditioning induces lifelong (and transgenerational) heat resilience and cross-tolerance (i.e., improved health of other systems) within the immune and metabolic systems. Epigenetic marks are responsible for transgenerational transmission of stress responses, challenging the assumption that epigenetic modifications are erased in germ cells at fertilization. Some of these changes are retained and passed down to subsequent generations. Epigenetic modifications will be followed in three generations of chickens, from in ovo (embryonic) heat conditioning, through life-long encounters with environmental challenges, insemination, primordial germ cells, and normal growth of two consecutive generations. Stress-, metabolic-, and inflammatory-related pathways will be studied in the blood and areas of the brain responsible for regulating such pathways, including the preoptic anterior hypothalamus and paraventricular nucleus of the hypothalamus. Epigenetic mechanisms include DNA methylation and interactions with histone modifications, and epitranscriptomic marks, and these will be assessed using global (via sequencing) and loci-specific (through nucleic acid and protein interactions) methods. The work will be performed concurrently at Virginia Tech in the U.S.A. and the Volcani Institute in Israel, providing robust results with chickens from different genetic backgrounds in different geographical locations. This project will be used as a platform to recruit students from underrepresented backgrounds into research, and will involve training for one graduate student researcher each year.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.