DISSERTATION RESEARCH: PHENOTYPIC RESPONSES TO URBAN HABITATS: A POTENTIAL ROLE FOR DNA METHYLATION

城市地区正在迅速扩张，对野生动物来说，机遇和挑战并存。虽然一些物种在城市地区的生存状况不佳，但另一些物种的生存状况却很好。之前的研究已经记录了城市和农村同一物种个体之间的许多差异，但关于这些差异是如何产生和维持的，人们知之甚少。一种可能的机制是DNA甲基化，这是一个在不改变潜在遗传密码的情况下影响基因表达的过程。DNA甲基化模式可以遗传，但也可能在个体一生中因环境刺激而改变。由于DNA甲基化使生物体的外部特征能够快速、稳定和可遗传地变化，它是解释物种如何适应新的栖息地和情况的最佳候选者，包括城市化。这项研究将比较城市和农村鸣禽的DNA甲基化模式，并将这些模式与之前观察到的这些相同群体之间的差异，特别是攻击行为和应激激素水平联系起来。城市和农村鸟类在DNA甲基化水平和位置上的差异是可以预测的，甲基化模式与观察到的行为和生理差异之间的关系也是如此。这项研究的结果将广泛适用，因为DNA甲基化是一个在从真菌到植物再到动物(包括人类)的分类群中发现的过程。这项研究将增加对城市栖息地如何影响生活在其中的当代和未来生物的理解，随着城市地区的不断发展，这一知识尤为重要。最后，两名本科生将参与这项研究，给他们宝贵的研究经验，这将使他们在科学职业生涯中取得进步。此外，还将为当地自然中心创建探索城市化对动物和人类影响的活动，让更广泛的公众了解这项研究的重要性。

Urban areas are rapidly expanding and present both opportunities and challenges for wild animals. While some species do poorly in urban areas, others do well. Previous research has documented many differences between urban and rural individuals of the same species, but little is known about how these differences are created and maintained. One possible mechanism is DNA methylation, a process that affects gene expression without changing the underlying genetic code. Patterns of DNA methylation can be inherited, but may also change within an individual's lifetime in response to environmental stimuli. Because DNA methylation enables rapid yet stable and heritable changes of an organism's outward characteristics, it is a prime candidate for explaining how species adapt to novel habitats and situations, including urbanization. This study will compare DNA methylation patterns of urban and rural songbirds and relate these patterns to previously observed differences, specifically aggressive behavior and stress hormone levels, between these same groups. Differences between urban and rural birds in DNA methylation levels and locations are predicted, as is a relationship between methylation patterns and observed differences in behavior and physiology. The results of this research will be broadly applicable, as DNA methylation is a process found in taxa ranging from fungi to plants to animals, including humans. This study will increase understanding of how urban habitats can affect current and future generations of organisms living in them, knowledge that is especially important as urban areas continue to grow. Finally, two undergraduate students will participate in this study, giving them valuable research experience that will advance them towards a career in science. In addition, activities exploring the impacts of urbanization on animals and humans will be created for the local nature center giving the broader public an awareness of why this research is important.