Comparative transcriptomics for nematode development

描述(由申请人提供)：我的主要研究目标是基于进化论方法破译发育过程中的转录控制。发育生物学中的一个长期存在的问题是确定一个非常强大的事件网络的遗传基础，这些事件网络指定了多细胞有机体的发育。线虫线虫在这一努力中提供了一个方便的模型，既展示了细胞自主的发育模式，也展示了细胞间的通讯模式。虽然这种生物体的高度一致的细胞谱系已经被优雅地研究，揭示了一些主要的调控因素，但对于在整个发育过程中作用于参与基因的限制因素，人们知之甚少。我们假设，将野生线虫分离株与现有线虫物种进行比较，将在分子细节上揭示这一过程的进化可塑性。我们的方法包括在基因的基础上比较两个进化时间框架的影响：通过比较野生菌株的微观进化和通过与不同的线虫物种比较的宏观进化。如果在线虫之间检测到足够的变异，比较转录数据有望通过识别每个基因的每个时间点的进化模式(纯化、阳性和中性)来解析可用的时间进程数据。这些预测模式通过使用反向遗传学和转基因菌株对一组基因表达具有有趣的保守性和差异性的基因进行了实验测试。

DESCRIPTION (provided by applicant): My primary research objective is to decipher transcriptional control in development based upon an evolutionary theoretic approach. A long-standing problem in developmental biology is to determine the genetic basis for the remarkably robust network of events that specify the development of a multicellular organism. The nematode C. elegans makes for a convenient model in this effort, exhibiting both cell-autonomous and cell-cell communication modes of development. While the highly uniform cell lineage of this organism has been elegantly studied, revealing a number of master regulators, little is known about the constraints that act upon the participating genes throughout development. We hypothesize that a comparison among wild C. elegans isolates and with extant Caenorhabditis species would reveal the evolutionary plasticity of the process in molecular detail. Our approach involves comparing, on a gene by gene basis, the effect of two evolutionary time frames: micro-evolution through a comparison of wild isolates and macro-evolution through a comparison with divergent Caenorhabditis species. Provided that sufficient variation is detected among the nematodes, the comparative transcriptomic data promises to resolve the available time course data by identifying the mode of evolution (purifying, positive, and neutral) for each time point of each gene. These predicted modes are experimentally tested by the use of reverse genetics and transgenic strains for a set of genes with interesting conservation and divergences in gene expression.