Developmental Genomics in C. elegans

描述（由申请人提供）：该项目的长期目标是详细描述和表征早期秀丽隐杆线虫胚胎中指定和模式C卵裂球谱系的pal-1转录网络。秀丽隐杆线虫的不变性使Sulston和他的同事能够描述正常发育的细胞谱系。这种描述在分析发育途径和机制方面已被证明是无价的。线虫基因组的测序提供了使用寡核苷酸微阵列监测所有预测基因表达水平的手段。在这里，我们建议将这些描述技术结合起来，然后使用秀丽隐杆线虫中可用的强大的分子和遗传工具来表征指定早期胚胎卵裂球命运的转录程序。pal-1活性对于确定C谱系是必要和充分的。我们假设pal-1控制着一个强大的基因网络，其调控结构将通过识别和表征许多pal-1靶基因，特别是它们的上游控制区来确定（Aim 1）。此外，我们假设该网络的发育稳健性主要是由于同源靶基因的功能冗余，但也取决于调节网络中非同源基因之间的补偿相互作用。多基因的RNAi （Aim 3）将揭示同源物之间的功能冗余。为了测试补偿调节相互作用所带来的发育稳健性，我们将首先使用数学模型（目标2）来预测基因网络结构，以识别特定的非同源基因进行类似分析（目标3）。该分析虽然仅限于pal-1活性的转录靶基因，但却是完整描述主调控因子活性的必要第一步。

DESCRIPTION (provided by applicant): The long-term goal of this project is to describe and characterize in detail the pal-1 transcriptional networks that specify and pattern the C blastomere lineage in the early C. elegans embryo. The invariant development of C. elegans allowed Sulston and co-workers to describe the cell lineage of normal development. This description has proven invaluable in the analysis of developmental pathways and mechanisms. The sequencing of the nematode genome has provided the means to monitor the expression levels of all predicted genes using oligonucleotide microarrays. Here, we propose to combine these descriptive technologies and then use the powerful molecular and genetic tools available in C. elegans to characterize the transcriptional program that specifies the fate of an early embryonic blastomere.pal-1 activity is necessary and sufficient to specify the C lineage. We hypothesize thatpal-1 controls a robust gene network, the regulatory structure of which will be determined by identifying and characterizing many pal-1 target genes, particularly their upstream control regions (Aim 1). Furthermore, we hypothesize that the developmental robustness of this network is due primarily to functional redundancy of homologous target genes, but depends as well on compensating interactions within the regulatory network among non-homologous genes. RNAi of multiple genes (Aim 3) will reveal functional redundancy among homologs. To test for developmental robustness conferred by compensating regulatory interactions we will first use mathematical modeling (Aim 2) to predict the gene network architecture to identify specific non-homologous genes for similar analysis (Aim 3). This analysis, although limited to those genes that are transcriptional targets of pal-1 activity, is the necessary first step to a complete description of the activity of a master regulator.