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PAL-1转录网络，该网络指定和模式早期线虫胚胎中的C卵裂球谱系。线虫的不变发育使Sulston和他的同事能够描述正常发育的细胞谱系。事实证明，这一描述在分析发展路径和机制方面非常有价值。线虫基因组的测序为利用寡核苷酸微阵列监测所有预测基因的表达水平提供了手段。在这里，我们建议结合这些描述技术，然后使用线虫中可用的强大分子和遗传工具来表征决定早期胚胎卵裂命运的转录程序。PAL-1活性是必要的，也是足够指定C谱系的。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(目标1)来确定。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，但也取决于非同源基因之间调节网络内的补偿相互作用。多基因的RNAi(目标3)将揭示同源基因之间的功能冗余。为了测试通过补偿调控相互作用所赋予的发育稳健性，我们将首先使用数学建模(目标2)来预测基因网络结构，以识别用于类似分析的特定非同源基因(目标3)。这种分析虽然局限于PAL-1活性的转录靶标基因，但它是完整描述主要调节因子活性的必要的第一步。

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.