Dissertation Research: Geographical Variation in Developmental Genetic Control of Polyphenism

动物的外貌或行为会随着环境的变化而在世代之间发生变化，这被称为多物性。多面性现象经常发生，允许动物以不同的方式利用现有基因，以更好地适应环境，但在基因水平上对其知之甚少。七叶树蝴蝶表现出季节性的翅膀颜色变化；也就是说，一个种群内的不同世代有不同的颜色。七叶树非常适合实验室生活，但在地理上也很广泛，并表现出巨大的颜色变化。翅膀颜色的变化被认为可以增强季节变化的树叶的伪装性；但七叶树物种发现于高度季节性的温带森林、干旱的地中海栖息地和相对季节性的热带栖息地。不同气候的七叶树物种之间的多物性如何变化，从而增加它们在环境中的存活率尚不清楚。研究的问题是：(1)不同地区的颜色变体之间的翼色素存在什么地理差异？(2)温度和日长阈值是什么触发了不同地区不同的颜色变体？以及(3)哪些基因表达变化与不同的机翼颜色有关？将使用化学分析、受控环境操作和现代遗传方法来提供颜色的分子和环境调节的综合图景。这一结果将使人们更好地理解基因调控如何影响动物的外观。通过这个项目，将指导本科生，并通过出版物和会议报告传播新的结果和方法。督导主任亦会向幼稚园至十二年级的教师和学生进行外展服务。

Animals can vary in appearance or behavior between generations in response to environmental changes; this is called polyphenism. Polyphenism occurs frequently and allows animals to use existing genes in different ways to be better adapted to their environments, but very little is known about it at the genetic level. Buckeye butterflies show seasonal wing color changes; that is, different generations within a population have different colors. Buckeyes are well suited to laboratory life but also geographically widespread and exhibit tremendous color variation. Wing color changes are thought to enhance camouflage in seasonally changing foliage; but buckeye species are found in highly seasonal temperate forests, arid Mediterranean habitats, and relatively aseasonal tropical habitats. How polyphenism may vary between buckeye species in different climates to allow increased survival in their environments is unclear. The research questions are: (1) What geographical variation exists for wing pigments between color morphs from different regions? (2) What temperature and day-length thresholds trigger the different color morphs in different regions? and (3) What gene expression changes are associated with the different wing colors? Chemical analyses, controlled environment manipulations, and modern genetic methods will be used to provide an integrative picture of molecular and environmental regulation of the colors. The results will provide a better understanding of how gene regulation can affect the external appearance of animals. Through this project undergraduate students will be mentored and novel results and methods will be disseminated via publications and meeting presentations. The PIs will also conduct outreach to K-12 teachers and students.