Collaborative Research: Mobile Elements and Primate Evolution

可移动元件是DNA片段，它们复制自己，然后插入基因组的其他地方。这些元素可以影响许多重要的进化过程，包括染色体的突变和重排。它们也可能在新物种的发展中发挥重要作用。尽管可移动元件占人类基因组的近30%，但人们对它们的起源及其复制和插入机制知之甚少。这项研究的主要目标是更多地了解移动元素及其在人类和灵长类进化中所扮演的角色。一些可移动的元件，特别是那些被命名为ALU和L1S的元件，要么存在于特定的染色体位置，要么不存在。由于移动元素在特定位置的存在是较新的或派生的状态，并且这些元素在插入后不会被删除，因此这些多态是进化分析的理想选择。在这个合作项目中，将从至少16个灵长类物种的不同集合中确定一系列至少100个Alu和L1元素，以便为灵长类进化研究提供资源。由于一些移动元素在关键的进化过程中扮演着重要的角色，将人类与其他灵长类物种进行比较将有助于确定我们物种的独特遗传属性。伴随人类物种形成的关键变化可能会被识别出来。因此，关于我们物种起源的重要信息将被获得。将对300人的不同集合进行100个L1插入元件的分型(这将被添加到相同个体中键入的100个Alu插入多态的现有集合中)。这将产生一个强大的资源来解决关于我们物种人口历史的问题。解剖学上的现代人在他们的历史上经历过人口瓶颈吗？如果是这样的话，这个瓶颈有多严重，它是什么时候发生的，发生在哪里？这项研究将有助于进一步检验这一假设，即现代人起源于非洲，后来有一小部分人从非洲迁徙到旧世界的其他地区。除了解决有关人类起源的问题外，该项目还将提供一个新识别和表征的可移动元素的资源，任何对灵长类遗传学感兴趣的研究人员都可以使用这些资源。该项目的一个重要方面是对研究生和本科生以及代表不足的少数群体成员进行培训。

Mobile elements are DNA segments that make copies of themselves that are then inserted elsewhere in the genome. These elements can influence many important evolutionary processes, including mutation and rearrangement of chromosomes. They may also play an important role in the development of new species. Although mobile elements make up nearly 30% of the human genome, little is known about their origins and their mechanisms of replication and insertion. The major goal of this research is to learn more about mobile elements and the roles they have played in human and primate evolution. Some mobile elements, particularly those termed Alus and L1s, are either present or absent at a specific chromosome location. Because the presence of a mobile element at a specific location is the more recent, or derived, state, and because these elements are not deleted after they are inserted, these polymorphisms are ideal for evolutionary analysis. In this collaborative project, a series of at least 100 Alu and L1 elements will be ascertained in a diverse collection of at least 16 primate species in order to provide a resource for primate evolutionary studies. Because of the role that some mobile elements play in key evolutionary processes, a comparison of humans with other primate species will help to define unique genetic attributes of our species. Key changes that accompanied human speciation may be identified. Thus, important information about the origins of our species will be obtained. A diverse collection of 300 humans will be typed for 100 L1 insertion elements (this will be added to an existing collection of 100 Alu insertion polymorphisms typed in the same individuals). This will produce a powerful resource for addressing questions about the demographic history of our species. Did anatomically modern humans experience a population bottleneck in their history? If so, how severe was this bottleneck, when did it occur, and where did it occur? This research will help to further test the hypothesis that modern humans originated in Africa, with a small subset of individuals later migrating out of Africa to other parts of the Old World. In addition to addressing questions about human origins, this project will provide a resource of newly identified and characterized mobile elements that can be used by any investigator interested in primate genetics. An important aspect of this project is the training of graduate and undergraduate students and of members of under-represented minority populations.