Breaks-independent recognition of homology in chromosomes

染色体同源性的不依赖断裂的识别

• 批准号: 7745479
• 负责人: Ekaterina Mirkin
• 金额: $ 5.22万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2011-06-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7745479
• 关键词: Binding Sites; Cell Nucleus; Cells; Chromosomes; DNA Sequence; DNA Sequence Rearrangement; Dosage Compensation (Genetics); Elements; Failure; Frequencies; Gene Expression; Gene Expression Regulation; Genome; Genome Stability; Genomics; Goals; Homologous Gene; Hot Spot; Human; Investigation; Laboratory Study; Lead; Maintenance; Malignant Neoplasms; Meiosis; Mental Retardation; Methodology; Molecular; Molecular Conformation; Organism; Outcome; Play; Process; Protein Binding; Research; Resolution; Role; Running; Saccharomyces cerevisiae; Saccharomycetales; Scanning; Sister; Spontaneous abortion; Structure; Techniques; X Chromosome; genome-wide; novel strategies

DESCRIPTION (provided by applicant): Breaks-independent recognition of homology in chromosomes is one of the remaining mysteries in the field of genome structure and function. It has been shown to be important in various organisms, in both somatic and meiotic cells. Such essential processes as regulation of gene expression, meiosis, X-chromosome dosage compensation and genomic surveillance for rearrangements, seem to rely on this phenomenon. Malfunction of meiosis is the leading cause of miscarriages and mental retardation in humans; malfunction of gene expression, as well as failure to maintain genomic stability, lead to cancer. Therefore, information about this important process is crucial for our understanding and possible control of these maladies. Yet its molecular mechanism is not known. Here, I propose to study breaks-independent pairing of homologous chromosomes in the budding yeast, using two complementary approaches. First, I will perform genome-wide high-resolution scan for pairing frequencies. Identification of regions with greater and lesser pairing activity will help to identify relevant determinants; additionally, identification of especially strong "hot spots" will facilitate direct investigation of the molecular mechanism of this process. Second, I will analyze a known pairing-active locus and assess whether pairing involves direct DNA/DNA recognition, or certain candidate genomic elements such as structure-prone DNA sequences and protein binding sites. For both approaches, I plan to employ the Chromosome Conformation Capture (3C) technique, recently developed in Dr. Kleckner's laboratory for studying three-dimensional conformation of chromosomes within nuclei. For the first aim, I have formulated a new version of this methodology as specifically required for this purpose. The proposed adaptation will expand the range of problems approachable by 3C to include not only interhomolog contacts but also inter-sister contacts, with many potential general applications. In the long run, my goal is to explain how homologous chromosomes recognize each other in the absence of breaks and to define the role that this recognition plays in fundamental genomic functions. This proposal focuses on studying interactions between homologous chromosomes, which are involved in meiosis, regulation of gene expression and maintenance of genomic stability. Malfunction of meiosis is the leading cause of miscarriages and mental retardation in humans; malfunction of gene expression, as well as failure to maintain genomic stability, lead to cancer. Therefore, information about this important process is crucial for our understanding and possible control of these maladies.

描述（由申请人提供）：与染色体中同源性同源性无关的识别是基因组结构和功能领域的其余奥秘之一。在体细胞和减数分裂细胞中，它在各种生物体中都很重要。对重排的基因表达，减数分裂，X染色体剂量补偿和基因组监测等基本过程似乎依赖于这种现象。减数分裂的故障是人类流产和智力低下的主要原因。基因表达的故障以及无法维持基因组稳定性导致癌症。因此，有关此重要过程的信息对于我们对这些疾病的理解和可能控制至关重要。然而，其分子机制尚不清楚。在这里，我建议使用两种互补方法研究萌芽酵母中同源染色体的独立于休息的配对。首先，我将对全基因组进行配对频率进行全基因组的高分辨率扫描。鉴定具有更大和更少的配对活动的区域将有助于确定相关的决定因素；另外，鉴定特别强烈的“热点”将有助于直接研究该过程的分子机制。其次，我将分析一个已知的配对活性基因座，并评估配对是否涉及直接DNA/DNA识别，还是某些候选基因组元素，例如易于结构的DNA序列和蛋白质结合位点。对于两种方法，我计划采用染色体构象捕获（3C）技术，该技术最近在Kleckner博士的实验室中开发，用于研究核内染色体的三维构象。对于第一个目的，我已经为此目的设计了一种新版本的这种方法。所提出的适应性将扩大3C可接近的问题的范围，不仅包括种间接触，还包括姐姐间的联系，以及许多潜在的一般应用。从长远来看，我的目标是解释在没有断裂的情况下如何相互认识的同源染色体，并定义了这种识别在基本基因组功能中所起的作用。该提案的重点是研究同源染色体之间的相互作用，这些染色体与减数分裂有关，基因表达调节和基因组稳定性的维持。减数分裂的故障是人类流产和智力低下的主要原因。基因表达的故障，以及无法维持基因组稳定性的导致癌症。因此，有关此重要过程的信息对于我们对这些疾病的理解和可能控制至关重要。