CAREER: Using Multiple Nuclear Introns to Reconstruct the History of Plumage Dichromatism in Orioles (Icterus).

最近的进展，包括在系统学中使用DNA测序，使达尔文关于生命树的愿景成为一个可行的目标，该愿景展示了所有有机体之间的进化关系。然而，在这一愿景成为现实之前，仍有一些挑战必须加以解决。主要的挑战之一是，几乎所有现有的近亲动物的分子系统学(进化树)都是基于母系遗传的线粒体DNA序列。线粒体DNA工作良好的原因有很多，但需要独立的核序列来测试这些线粒体树，在那里它们是有争议的。已发表的金莺属线粒体树是所有鸟类系统学中最具争议的之一，因此使用核序列来测试它是一个理想的系统发育。将对五个不同的核内含子区域进行测序，以评估金莺进化树。与蛋白质编码基因区域相比，核内含子突变更快，因此它们是核基因组中快速进化序列的良好候选区域。由此产生的进化树将被用来推断金莺羽毛颜色差异(两性之间的二形性)的历史。在某些动物群体中，雌性颜色的变化可能是二型性得失的主要原因。在金莺和许多其他鸟类群体中，温带候鸟的雌性通常是暗色的，而热带非候鸟的雌性通常是精心制作的颜色。因此，这些金莺提供了一个很好的机会来重建羽毛颜色二型性的变化，并调查女性羽毛亮度变化的可能原因。此外，该项目将测试和展示结合来自内含子、线粒体DNA和形态的数据的价值。结合多个核内含子序列可能为构建所有密切相关的动物物种的全基因组树提供基础。巴尔的摩县马里兰大学的凯文·奥姆兰教授的这一研究项目为教育和外展活动提供了许多机会。该项目包括马里兰大学巴尔的摩县分校(UMBC)和墨西哥国立自治大学(UNAM)之间的国际学生交换项目。在过去的六年里，奥姆兰教授一直在与北卡罗来纳大学的研究人员开展研究和本科生交流项目。这一交流模式将扩大到包括密歇根州立大学的学生，特别是来自密歇根大学著名的少数民族科学项目的学生，他们将帮助墨西哥的田野和博物馆研究。来自马里兰州和墨西哥的本科生将有机会出国旅行，参与广泛的系统学研究。研究小组将制作一个关于金莺的双语网站，以帮助向说英语和西班牙语的人传播研究结果，并促进对进化、分类学和生物多样性的理解。在密歇根州立大学的课堂上，金莺研究计划将被用作主动学习练习中的扩展案例研究，以帮助阐明科学的过程。巴尔的摩金莺是州鸟，也是当地棒球队的吉祥物，这有助于学生和公众了解这项研究。这一国际研究和交流计划将促进美国和墨西哥的合作，并向不同的受众促进系统学研究。

Recent advances including the use of DNA sequencing in systematics have made Darwin's vision of a Tree of Life, showing evolutionary relationships among all organisms, a feasible goal. However, there are still challenges that must be addressed before this vision can become reality. One of the main challenges is that virtually all current molecular phylogenies (evolutionary trees) for closely related animals are based on maternally inherited mitochondrial DNA sequences. Mitochondrial DNA works well for many reasons, but independent nuclear sequences are needed to test these mitochondrial trees where they are controversial. The published mitochondrial tree for orioles is one of the most controversial in all of bird systematics, so it is an ideal phylogeny to test using nuclear sequences. Five different nuclear intron regions will be sequenced to evaluate the oriole evolutionary tree. Nuclear introns are free to mutate more rapidly than protein coding gene regions, so they are good candidate regions for rapidly evolving sequences in the nuclear genome. The resulting evolutionary tree will be used to infer the history of plumage color differences (dimorphism between the sexes) in orioles. In some groups of animals, changes in female color may be the main cause of gains and losses of dimorphism. In orioles and many other groups of birds, females in temperate migratory species are generally dull colored, whereas females in tropical non-migratory species are generally elaborately colored. These orioles therefore present an excellent opportunity to reconstruct changes in plumage color dimorphism, and investigate the possible causes of changes in female plumage brightness. In addition, this project will test and demonstrate the value of combining data from introns, mitochondrial DNA and morphology. Combining multiple nuclear intron sequences may provide a basis for constructing whole genome trees for all closely related animal species. This research program by Prof. Kevin Omland at University of Maryland Baltimore County provides many opportunities for education and outreach activities. The project includes an international student exchange program between the University of Maryland Baltimore County (UMBC) and the National Autonomous University of Mexico (UNAM). Over the last six years, Prof. Omland has been developing a research and undergraduate exchange program with researchers at UNAM. This exchange model will be expanded to include UMBC students, especially from UMBC's well-known minority science programs, who will assist with field and museum research in Mexico. Undergraduate students from Maryland and Mexico will have the opportunity to travel internationally and participate in a wide range of systematics research. The research team will produce a bilingual website on orioles to help disseminate findings to both English and Spanish speakers, and to promote understanding of evolution, systematics and biodiversity. In the classroom at UMBC the oriole research program will be used as an extended case study in active learning exercises to help illuminate the process of science. The Baltimore Oriole is the state bird and the mascot of the local baseball team, which helps make this research accessible to students and the public. This international research and exchange program will foster US-Mexico collaboration, and promote systematics research to a diverse audience.