Developmental Control in C. elegans

描述(申请人提供)：microRNAs(MiRNAs)通常通过与目标mRNAs的3‘非翻译区结合来抑制基因表达，数以千计的mRNAs已被预测为动物体内数百个miRNAs的靶标。尽管在过去的十年中进行了大量的研究，但大多数调控miRNA：：mRNA的广泛生理功能的相互作用仍有待阐明。在线虫中，遗传分析只将一小部分miRNAs或miRNA家族与发育中的重要作用联系起来。在miRNAs功能研究中遇到的困难可能部分归因于来自不同家族的多个miRNAs可能协作调节一组特定生理功能的靶基因。我们还可以假设，大量的miRNAs可能在细胞过程中发挥作用，这些过程涉及动物对环境变化的反应，如营养物质的可获得性、应激条件和病原体感染。我们的目标是获得不同组织和不同生理条件下的动态miRNA：：靶相互作用的全球视角，以获得关于miRNA在应激和感染反应中所介导的功能的见解。我们建议将新的系统化方法与基于个体基因的分析相结合来解决这个问题，以线虫线虫为模型系统。我们将首先通过扰乱选定组织中所有miRNAs的活动来评估miRNAs的生理功能，并研究其发育和非发育后果，包括对应激和感染的反应。然后，我们将通过应用AIN-2免疫沉淀、高通量RNA分析和计算方法来识别和分析发育过程中选定组织中的miRNA：：靶相互作用。这一方法将进一步用于确定动物对食物匮乏、病原体感染和其他应激反应过程中的动态miRNA：：靶相互作用。最后，我们将进行实验来验证所选对的miRNA：：靶相互作用，并分析它们在胁迫和病原体响应中的功能。这项研究的结果将为miRNA调控的重要功能和动物抵御环境应激和感染的机制提供重要的见解。 与公共卫生相关：microRNA是进化上保守的非编码小RNA，已被证明在细胞和发育过程的广泛方面发挥关键作用，包括许多人类疾病，如癌症、心脏和神经疾病，以及动物对各种应激的反应。这项赠款下的研究有望为miRNA在应激反应和发育中的功能提供新的见解，从而做出坚实的贡献。

DESCRIPTION (provided by applicant): MicroRNAs (miRNAs) commonly repress gene expression by binding to the 3' untranslated region of target mRNAs, and thousands of mRNAs have been predicted to be targets of hundreds of miRNAs in animals. Despite intense studies in the past decade, the majority of regulatory miRNA::mRNA interactions for a broad spectrum of physiological functions remain to be elucidated. In C. elegans, genetic analyses have only linked a small percentage of miRNAs or miRNA families to prominent roles in development. The difficulty encountered in functional studies of miRNAs may be attributed in part to that multiple miRNAs from different families may collaborate to regulate a set of target genes for specific physiological functions. We may also hypothesize that a large number of miRNAs may function in cellular processes involved in animals' responses to environmental changes such as nutrient availability, stress conditions and pathogen infection. Our goal is to gain a global view of dynamic miRNA::target interactions in different tissues and under different physiological conditions to obtain insights regarding miRNA-mediated functions in stress and infection responses. We propose to combine novel systematic approaches with individual gene- based analysis to tackle the problem, using the nematode C. elegans as a model system. We will first evaluate physiological functions of miRNAs by disrupting activities of all miRNAs in selected tissues and examine the developmental and non- developmental consequences, including responses to stresses and infections. We will then identify and analyze miRNA::target interactions in selected tissues during development by applying AIN-2 immunoprecipitation, high-throughput RNA analysis, and computational methods. This approach will further be used to identify dynamic miRNA::target interactions during animals' responses to food deprivation, pathogen infection and other stresses. Finally, we will carry out experiments to verify miRNA::target interactions for selected pairs and analyze their functions in stress and pathogen responses. The results of this study should provide important insights regarding important functions of miRNA regulations and mechanisms of animals' defense against environmental stresses and infections. PUBLIC HEALTH RELEVANCE: microRNAs are evolutionarily conserved small, non-coding RNAs that have been shown to play critical roles in a broad aspect of cellular and developmental processes, including many human diseases such as cancers, cardiac and neurological diseases, as well as animal's responses to various stresses. Research under this grant is expected to make a solid contribution by providing new insights into miRNA functions in stress responses and development.