Evolution of allorecognition in a basal chordate

个体区分自我和非自我/自我的能力被称为异源识别，在整个动物王国中都有发现。这种免疫识别过程是由令人难以置信的不同分子控制的，个体动物几乎具有这些分子的独特组合，基本上形成了个体特征。最好的例子是组织移植：成功的移植取决于供体和受体之间的这些特征的匹配，否则组织将被视为外来的而被拒绝。负责的分子也被认为控制其他过程，例如确定另一个个体的相关性的能力。目前尚不清楚的是，这些分子是如何变化的：观察到的多样性比进化数学模型预测的要高出10到100倍。同样重要的是如何认识到这种多样性并采取行动。这项建议的重点是了解创造、维持和应对这种遗传多样性的能力所依据的进化力量。Schlosseri是一种海洋动物，其异源识别反应发生迅速，易于研究。研究人员最近已经确定了这一过程的分子基础。鉴于其方便的生活史特征，再加上其他研究人员的结果，研究人员现在可以开始描述与创造和维持这种生物的遗传多样性有关的事件。这包括描述自然种群内部和之间的多样性，这将导致对进化过程的更清晰的理解。B。施洛塞里也有被认为是由这些分子控制的行为反应，这也将被直接测试。这些研究的基本吸引力和直接的方法吸引了许多本科生和高中生（许多来自代表性不足的群体），并被纳入每年春季和夏季的独立研究项目。

The ability of an individual to discriminate between self and non/self is called allorecognition, and is found throughout the animal kingdom. This immunological recognition process is controlled by incredibly diverse molecules, and individual animals have nearly unique combinations of these, essentially making an individual signature. The best example of this is tissue transplantation: successful transplantation depends on a match of these signatures between donor and recipient, or the tissue will be rejected as being foreign. The molecules responsible are also thought to control other processes, for example the ability to determine the relatedness of another individual. What is not understood is how these molecules can be so varied: the observed diversity is 10 to 100-fold higher than what evolutionary mathematical models predict. Equally important is how this diversity is recognized and acted upon. This proposal focuses on understanding the evolutionary forces which underlie the ability to create, maintain and respond to this genetic diversity. Botryllus schlosseri, is a marine animal whose well studied allorecognition reaction occurs rapidly and can be easily studied. The investigators have recently identified the molecules which underlie this process. Given its convenient life-history traits, coupled with results from other investigators, the investigators can now begin to characterize the events involved with creating and maintaining this genetic diversity of this organism. This includes describing the diversity within and among natural populations, which will lead to a clearer understanding of the evolutionary processes responsible. B. schlosseri also has behavioral responses thought to be controlled by these molecules, which will also be directly tested. The basic appeal of these studies and the straightforward methodology attract numerous undergraduate and high school students (many from under-represented groups), and is incorporated into independent research projects every spring and summer.