RUI: Functional analysis of the exon junction complex in planarian stem cells and regeneration

非技术段：许多生物，包括人类在内，在身体受伤或患病后，具有一定的再生丧失或受损身体部位的能力。然而，这种能力的程度在不同物种之间有很大差异，而且解释这种差异的生物学机制还没有得到很好的理解。这个项目将研究在被称为涡虫的水生扁虫的非凡再生能力中起关键作用的基因，涡虫是一种可以在一周多的时间内从微小的身体碎片重新形成完整个体的动物。完成提出的目标将推进我们对驱动这一过程的大干细胞群是如何被调节的认识。大多数研究活动将由基恩州立学院的本科生进行，为大学毕业后的专业培训和生命科学的职业生涯提供有价值的准备。与高中生参与的科学推广活动一起，这将加强新罕布什尔州培养技术熟练的劳动力的努力，这对该州生物技术和高科技制造业的进一步发展至关重要。技术段落：本项目将描述成体干细胞中基因表达的转录后调控机制，以地中海扁虫为模式生物。具体来说，学生将完成外显子连接复合体（EJC）的功能分析，EJC是RNA生物化学的关键调节因子，在干细胞生物学中具有潜在的保守性，但鲜为人知的作用。先前的工作已经确定了EJC在剪接、剪接mRNA从细胞核输出、翻译控制和无义介导的mRNA衰变中的功能。在发育过程中，EJC与一些基因特异性调控机制有关；然而，其在成年生物自我更新细胞类型中的生化功能和假定的RNA靶点在很大程度上是未知的。本研究的研究目标将建立在初步数据的基础上，表明EJC是涡虫干细胞维持所必需的：1)利用RNAi和原位杂交技术表征EJC亚基在组织稳态和再生过程中的功能和表达；2)结合候选基因和无偏RNA-Seq方法鉴定EJC靶rna。本研究的完成将增强我们对成体干细胞在组织更新和修复过程中调控基因表达的分子机制的理解。PI将完全与本科生和高中生一起开展这项工作，以加强新罕布什尔州的STEM教育工作。

Non-Technical Paragraph: Many organisms, including humans, have some capacity to regenerate lost or damaged body parts following physical injury or disease. However, the extent of this ability varies considerably from one species to the next, and the biological mechanisms accounting for this variability are not well understood. This project will study genes that play a key role in the remarkable regenerative abilities of aquatic flatworms called planarians, animals that can re-form entire individuals from tiny body fragments in just over a week. Completion of the proposed objectives will advance our knowledge of how the large stem cell population that drives this process is regulated. Most research activities will be carried out by undergraduate students at Keene State College, providing valuable preparation for post-collegiate professional training and careers in the life sciences. Together with science outreach activities involving high school students, this will enhance New Hampshire's efforts to develop a technically proficient workforce crucial to further growth of the state's biotechnology and high-tech manufacturing industries.Technical Paragraph: This project will characterize post-transcriptional regulatory mechanisms governing gene expression in adult stem cells, using the planarian flatworm Schmidtea mediterranea as a model organism. Specifically, students will complete a functional analysis of the exon junction complex (EJC), a key regulator of RNA biochemistry with potentially conserved, yet poorly understood roles in stem cell biology. Prior work has established functions for the EJC in splicing, export of spliced mRNAs from the nucleus, translational control, and nonsense-mediated mRNA decay. The EJC has been linked to some gene-specific regulatory mechanisms during development; however, its biochemical function(s) and presumed RNA target(s) in self-renewing cell types in adult organisms are largely unknown. The research objectives of the current study will build upon preliminary data showing that the EJC is required for stem cell maintenance in planarians by: 1) Using RNAi and in situ hybridization to characterize the function and expression of EJC subunits during tissue homeostasis and regeneration; and 2) Combining candidate-gene and unbiased RNA-Seq approaches to identify EJC target RNAs. Completion of this research will enhance our understanding of molecular mechanisms governing gene expression in adult stem cells during tissue renewal and repair. The PI will undertake this work entirely with undergraduate and high school students to enhance STEM educational efforts in New Hampshire.