Chromatin Domain Structure and Function

描述（由申请人提供）：尽管存在广泛的相关性，但在最高水平的染色质折叠或大规模染色质结构与转录调节之间尚未建立直接的功能关系。同样，尽管核内基因定位的变化与特定核室的关联具有广泛的相关性，但我们仍然不知道基因是如何改变核内位置和关联的，更不用说了解这些变化的功能后果了。我们的长期目标是确定大规模的染色质折叠和特定基因位点的核内定位，确定这种折叠和核内定位的顺式和反式决定因素，并了解这种水平的染色质组织在转录调控方面的功能意义。本建议的具体目标是：1。确定大规模染色质压缩与转录激活之间的关系。2. 确定核斑点区隔化与转录活性和/或RNA加工之间的关系。3. 确定定位到核外周和特异性表观遗传修饰与转录活性和诱导之间的关系。该项目将利用BAC转基因的新系统来重建内源性基因位点的关键特征，以及在活细胞和超微结构水平上可视化特定染色体位点的新方法。我们的项目将严格测试新旧模型，以了解最高水平的染色质折叠如何调节基因表达。对更广泛的基础科学和生物技术的额外影响将来自我们对染色体结构和动力学可视化新技术的持续发展，以及这些方法在改进转基因和多转基因表达方面的应用。

DESCRIPTION (provided by applicant): Despite extensive correlations, a direct functional relationship has not yet been established between the highest levels of chromatin folding, or large-scale chromatin structure, and regulation of transcription. Similarly, despite extensive correlations of changes in intranuclear gene positioning and association with specific nuclear compartments, we still do not know how genes change intranuclear positions and associations, let alone understand the functional consequences of these changes. Our long-term objectives are to determine the large-scale chromatin folding and intranuclear positioning of specific gene loci, to identify the cis and trans determinants of this folding and intranuclear positioning, and to understand the functional significance of this level of chromatin organization with regard to transcriptional regulation. The specific aims of this proposal are to: : 1. Determine the relationship between large-scale chromatin compaction versus transcriptional activation. 2. Determine the relationship between nuclear speckle compartmentalization versus transcriptional activity and/or RNA processing. 3. Determine the relationship between localization to the nuclear periphery and specific epigenetic modifications versus transcription activity and induction. This project will exploit a novel system using BAC transgenes to reconstitute key features of endogenous gene loci as well as new methodologies for visualizing specific chromosome loci in live cells and at the ultrastructural level. Our project will critically test both old and new models for how the highest levels of chromatin folding modulate gene expression. Additional impact on a still wider range of basic science and biotechnology will come from our continued development of new technology for visualizing chromosome structure and dynamics and application of these methods for improved transgene and multi-transgene expression.