Evolution of Developmental Gene Regulatory Networks

要理解进化，责任止于DNA，因为具有共同祖先的物种之间的不同特征是遗传地编码在它们不同的DNA基因组中。戴维森实验室设计了一些实验，以确定在一个特定的进化案例中究竟发生了什么，这些案例可以在DNA水平上进行实验分析。他们认为，最有趣的进化特征是那些控制身体结构发展的特征，尽管人们对进化有很多看法，但很少有人能直接指出导致具体差异的序列。他们还提出，这些差异几乎总是在模块化控制序列中，这些序列专门决定基因在何处、何时以及如何强烈地表达以响应细胞调节状态。戴维森实验室将把重点放在发展海胆和海星上，它们在大约5亿年前有一个共同的祖先，它们的发育控制系统包括几个案例，通过比较发现相同的基因起着截然不同的作用。这种不同的调控导致了两种胚胎，在某些方面，在形式和功能上非常不同。戴维森实验室已经开发出一种技术来揭示这些控制系统中重要的差异，并通过实验将它们相互转换。关于进化的具体知识不仅是在机械水平上理解我们自己和所有其他动物的生物学的基础，而且将有巨大的实际回报。进化是我们基因控制系统变化的唯一天然实验室。要重新设计这些系统用于治疗或其他良性目的，将需要我们了解这些系统中允许和禁止变化的规则。戴维森实验室通过开发新的方法和技术，以及在揭示发育过程中的基因调控回路方面的开创性工作，对发育生物学社区产生了重大而广泛的影响。该实验室在学生培训方面也有良好的记录，并参加了加州理工学院的本科生暑期冲浪项目。

To understand evolution the buck stops at the DNA, since the characters that differ between species that have a common ancestor are heritably encoded in their different DNA genomes. The Davidson laboratory has designed experiments to determine what really happened in a specific case of evolution that can be analyzed experimentally at the DNA level. They argue that the most interesting evolutionary features are those that control development of the body plan and that while there is much hand-waving about evolution, there are few cases where one can put one''s finger directly on the sequences that cause specific differences. They also propose that these differences are almost always in the modular control sequences that specifically determine where, when and how intensely genes are expressed in response to cellular regulatory state. The Davidson laboratory will focus on developing sea urchins and sea stars, which had a common ancestor about a half billion years ago and whose developmental control systems include several cases where comparisons reveal the same genes doing very different things. This differential regulation results in two kinds of embryos that are, in some respects, quite distinct in form and function. The Davidson laboratory has developed the technology to uncover the differences that matter in these control systems, and to convert them into one another experimentally. Nuts and bolts knowledge of evolution is not only basic to understanding our own and all other animals'' biology at a mechanistic level, but will have a gigantic practical payoff. Evolution is our only natural laboratory for change in genomic control systems. To re-engineer these systems for therapeutic or other benign purposes, will require that we learn the rules of allowed and forbidden change in these systems. The Davidson laboratory has significant broader impacts on the developmental biology community by developing new approaches and technologies and for pioneering work on unraveling gene regulatory circuitry during development. The laboratory also has a strong record of student training and participates in the Caltech''s summer SURF program for undergraduates.