Live Imaging of the Genesis and Differentiation of the Sympathetic Nervous System

生物学的一个主要焦点是了解协调发育中的胚胎形态发生的细胞和分子机制。传统上，大多数这种分析都是在固定组织上进行的，尽管信息丰富，但不允许捕获介导形态发生事件的动态细胞运动。鉴于这些限制，人们越来越认识到，实时成像可以为我们提供一个非常强大的机制来阐明多个关键的生物事件。这种技术可以应用到的一个有趣的发展系统是迁移神经嵴。神经嵴是一个异质的祖细胞群，它们在整个脊椎动物胚胎中迁移，并产生大量的关键衍生物，包括周围神经系统的绝大多数神经元和胶质细胞，面部的软骨和中胚层，以及皮肤的黑素细胞。100多年来，这一系统一直是研究的主要课题，这些研究对我们理解干细胞、环境因素对细胞分化的影响以及预模式、内在因素在细胞命运中的作用做出了重大贡献。由于自主神经系统在维持所有脊椎动物的体内平衡中起着关键作用，因此我们将在本提案中研究这个系统。随着荧光探针的出现，可以在活组织中跟踪迁移细胞数小时或数天。从这些数据中，科学家们对神经嵴细胞如何迁移并形成其独特的衍生物有了新的看法。此外，在鸡胚中，有许多机制进行功能的得失分子扰动。因此，该方法是结合这两种强大的技术，以阐明介导交感神经系统形成的细胞和分子机制，从它们的前体神经嵴细胞。这里提出的实验为本科生和研究生提供了一个很好的教育训练机会，这些实验获得的数据将在PI在校园教授的本科课程中进行讨论和分析。此外，PI经常带小学生到实验室，这样他们就可以在共聚焦显微镜下体验到在真实的活胚胎中观察活细胞运动的快感。对于非科学家来说，没有比在实验室里亲身体验更能使科学变得直接和有形的有效方法了。

A major focus in biology is to understand the cellular and molecular mechanisms that orchestrate the morphogenesis of a developing embryo. Traditionally, most of this analysis has been conducted on fixed tissue, which although informative, does not allow for the capture of the dynamic cellular movements that mediate morphogenetic events. Given these constraints, it has become increasingly recognized in the field that live imaging can provide us with an extremely powerful mechanism for elucidating multiple key biological events. A fascinating developing system to which this technology can be applied, is the migrating neural crest. The neural crest is a heterogeneous population of progenitor cells that migrate throughout the vertebrate embryo and give rise to a plethora of key derivatives, including the vast majority of the neurons and glia of the peripheral nervous system, the cartilage and mesectododerm of the face, and the melanocytes of the skin. This system has been a major topic of study for over 100 years and these studies have contributed significantly to our understanding of stem cells, the effects of environmental cues on cellular differentiation and the role of prepatterning, intrinsic cues in specifiying cell fate. Because of the critical role the autonomic nervous system plays in maintaining homeostasis of all vertebrates, it is this system which we will investigate in this proposal. With the advent of fluorescent probes, migrating cells can be followed in living tissue for hours or days. From these data, scientists have developed new views of how neural crest cells migrate and form their distinctive derivatives. In addition, in the chick embryo there are numerous mechanisms for conducting gain-and-loss of function molecular perturbations. Thus, the approach is to combine these two powerful technologies in order to elucidate the cellular and molecular mechanisms that mediate the formation of the sympathetic nervous system from their precursor neural crest cells. The experiments proposed here provide an excellent educational training opportunity for both the undergraduate and graduate students who will conduct the proposed experiments, and data gained from these studies will be discussed and analyzed in the undergraduate courses the PI teaches on campus. Furthermore the PI often brings elementary students to the lab so that they can experience the thrill of watching live cells move in a real live embryo on the confocal microscope. There is no more effective means to make science immediate and tangible for the non-scientist than first hand experience in the lab.