Molecular Dissection of Drosophila Hox Gene Cis-Regulatory Modules

项目摘要 我们DNA中的关键基因是如何调控的？他们的表达是如何在适当的空间中协调的 以及胚胎发育期间的时间？这些问题对我们的 对动物和人类的发育程序的理解。尽管如此，我们目前的 对基因表达调控在分子水平上的理解还不是很清楚 肤浅的。已有研究表明，关键发育基因的转录受 多种方式由特定区域的相邻非编码基因组DNA序列组成。这些 独特的顺式调节模块(CRM)，包括转录增强子、绝缘体和 已经发现，在所有的真核模型系统中，沉默分子都能调节基因表达。 目前为止已经研究过了。在某些情况下，已经发现特定的转录因子结合在 并对其活动进行规范。然而，决定哪里的分子机制 转录因子结合在大多数CRM序列中，以及这种结合如何调节CRM功能 目前仍不清楚。 果蝇双胸复合体的HOX基因是决定动物身体的关键基因 在胚胎发育期间做好计划。HOX基因在大鼠体内的时空表达 发育中的胚胎由CRM控制。我们的初步研究表明，在CRM的序列 果蝇双胸复合体在果蝇属内进化迅速。这是很明显的 相比之下，HOX基因在所有双边动物中都是保守的。一大套 果蝇双胸复合体中已知的增强子CRM及其序列的快速进化 在这些跨越不同果蝇物种的CRM上，提供了一个令人兴奋的机会来研究 CRM序列、转录因子结合与顺式调控的关系 功能。 这一提议的最终目的是阐明控制 序列水平上增强子CRM的功能活性。我们建议的研究还将 洞察顺式调控功能在不同物种中的演变。从长远来看 PI的科学目标是全面研究细胞周期调控的分子机制 区域实现了对整个双胸复合体的基因表达的协调控制。这个 这项提案的主要重点将是生物信息学鉴定和功能 果蝇已知CRM中特异性转录因子结合位点的特征 双胸复合体。进一步的实验来测试已知CRM的保守亚区的功能 并调查远亲客户关系管理亚区的功能兼容性。 果蝇物种将揭示客户关系管理体系结构和功能活动的演变。

Project Summary How are key genes in our DNA regulated? How is their expression coordinated in the proper space and time during embryonic development? These questions have enormous implications in our comprehension of the developmental program in animals and humans. Despite this fact, our current understanding of regulation of gene expression at the molecular level remains somewhat superficial. It has been shown that the transcription of critical developmental genes is controlled in a variety of ways by specific regions of neighboring non‐coding genomic DNA sequences. These distinct cis‐regulatory modules (CRMs), which include transcriptional enhancers, insulators, and silencers, have been found to regulate gene expression in all the model eukaryotic systems studied so far. In some cases, specific transcription factors have been found to bind at sequences in the CRMs and to regulate their activity. However, the molecular mechanisms that determine where transcription factors bind within most CRM sequences and how this binding regulates CRM function remain unclear. The Hox genes of the Drosophila bithorax complex are critical genes that determine the animal body plan during embryonic development. The expression of Hox genes spatially and temporally in the developing embryo is controlled by CRMs. Our initial studies show that sequences at the CRMs of the Drosophila bithorax complex are rapidly evolving within the Drosophila genus. This is in sharp contrast to the Hox genes, which are conserved across all bilaterian animals. The large set of known enhancer CRMs at the Drosophila bithorax complex, and the rapid evolution of the sequences at these CRMs across different Drosophila species, provide an exciting opportunity to study the relationship between sequences at the CRMs, transcription factor binding and cis‐regulatory function. The ultimate goal of this proposal is to elucidate the molecular mechanisms which control functional activity of the enhancer CRMs at the sequence level. Our proposed studies will also provide insight into the evolution of cis‐regulatory function across different species. The long term scientific goal of the PI is to fully investigate the molecular mechanisms by which the regulatory regions achieve coordinated control of gene expression across the entire bithorax complex. The major focus of this proposal will be on the bioinformatic identification and functional characterization of specific transcription factor binding sites within known CRMs of the Drosophila bithorax complex. Further experiments to test conserved sub‐regions of known CRMs for functional activity and to investigate the functional compatibility of CRM sub‐regions from distantly related Drosophila species will shed light on the evolution of CRM architecture and functional activity.