BRC-BIO: Analyzing the role of Drosophila variant Polycomb Repressive Complexes in developmental gene transcription

由于发育过程中基因表达的调控，多细胞生物是由功能独特的单个细胞组成的。发育基因调控在很大程度上是由许多蛋白质复合物在适当的发育窗口打开或关闭基因而实现的。一个重要的例子是多梳抑制复合体，它关闭了一组特定的发育基因。这个复合体是如何在早期发育中选择正确的基因来沉默的还不得而知。本项目将利用果蝇作为模式生物来研究这种沉默复合体在协调发育基因表达中的作用。发现果蝇中多梳抑制复合物沉默基因的机制将有助于我们了解哺乳动物的发育。该项目的另一个重要目标是增加传统上因种族或种族而被排除在伊曼纽尔学院本科研究经历中的人的参与。学生研究人员将使用遗传、分子和生化技术来解决这个项目的目标。与哈佛医学院和布兰迪斯大学的研究人员的合作将促进PEER本科生与更广泛的科学界的接触。其目标是激励更多的PEER学生在STEM领域从事职业。多细胞发育是由细胞类型特异性转录程序的部署所控制的，其中单个基因组在细胞增殖和特化过程中随着时间和空间的推移而被明显利用。这种现象是通过基因表达的精确协调来实现的，基因表达启动了生物体不同细胞类型的分化。染色质调控因子已被发现对发育转录程序的调控至关重要，但这些因子在胚胎发育过程中如何协调基因表达的机制尚不清楚。一个高度保守的染色质调控系统在发育模式和细胞分化中起着核心作用，包括Polycomb Group （PcG）蛋白。这些蛋白通常存在于两种不同类型的Polycomb suppression Complexes （PRCs）中：PRC1和PRC2。PI的实验室最近在果蝇中发现了变体PRC1 （vPRC1）复合物，它们与哺乳动物复合物具有很强的模块化保守性，这表明了一种古老的功能多样性。这项工作的目的是了解vPRC1复合物在协调正常发育至关重要的细胞类型特异性转录中的作用。在本项目中，本科生科学家将使用多种方法对其中一种vPRC1复合物进行功能表征，包括交联、串联亲和纯化、蛋白质伴侣和DNA结合位点的综合分析，同时使用功能遗传学方法来解剖果蝇正常发育过程中蛋白质复合物的变化。这一建议的成功完成将提供变异PRC1复合体在发育基因调控中的功能机制细节。由此产生的见解将被证明对哺乳动物细胞的未来分析有用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Multicellular organisms are composed of individual cells that function distinctly, due to the regulation of gene expression during development. Developmental gene regulation is largely made possible by many protein complexes that turn genes on or off at appropriate developmental windows. An important example is the Polycomb Repressive Complex, which turns off a specific set of developmental genes. How this complex selects the correct genes to silence during early development is still unknown. This project will utilize the fruit fly as model organism to study the role of this silencing complex in orchestrating developmental gene expression. Discovering the mechanism by which Polycomb Repressive Complexes silence genes in the fruit fly will inform our understanding of development in mammals. Another significant goal of this project is to increase the participation of persons traditionally excluded because of their ethnicity or race (PEERs) in undergraduate research experiences at Emmanuel College. Student researchers will use genetic, molecular, and biochemical techniques to address the aims of this project. Collaborations with researchers from Harvard Medical School and Brandeis University will facilitate engagement of PEER undergraduate students with the broader scientific community. The goal is to inspire larger numbers of PEER students to pursue careers in STEM.Multicellular development is governed by the deployment of cell-type specific transcriptional programming, in which a single genome is utilized distinctly over time and space as cells multiply and specialize. This phenomenon is achieved by the precise coordination of gene expression that initiates the differentiation of the different cell types of an organism. Chromatin regulatory factors have been found to be essential for regulation of developmental transcriptional programming however the mechanism behind how these factors coordinate gene expression during embryonic development remains unclear. One highly conserved chromatin regulatory system that plays a central role in developmental patterning and cell differentiation includes the Polycomb Group (PcG) proteins. These proteins are typically found in two distinct types of Polycomb Repressive Complexes (PRCs): PRC1 and PRC2. The PI's lab recently identified variant PRC1 (vPRC1) complexes in Drosophila that have strong modular conservation with mammalian complexes, suggesting an ancient functional diversity. The goal of this work is to understand the role of vPRC1 complexes in coordinating the cell-type specific transcription critical for normal development. In this project, undergraduate student scientists will functionally characterize one of the vPRC1 complexes using a variety of methods, including crosslinking, tandem affinity purification, and integrated analysis of protein partners and DNA binding sites, in parallel with functional genetic approaches to dissect the changes in protein complexes during normal development in Drosophila. Successful completion of this proposal will provide mechanistic details for function of a variant PRC1 complex in developmental gene regulation. Resulting insights will prove useful for future analyses in mammalian cells.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.