ROLE OF G4-DNA IN THE PAIRING OF CHROMOSOMES

G4-DNA 在染色体配对中的作用

• 批准号: 3300363
• 负责人: WALTER GILBERT
• 金额: $ 16.74万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-04-01 至 1992-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3300363
• 关键词: DNA; DNA binding protein; DNA footprinting; Saccharomyces; antibody; crosslink; cytogenetics; electron microscopy; fungal genetics; gel electrophoresis; genetic recombination; guanine; meiosis; molecular cloning; molecular genetics; monoclonal antibody; nucleic acid hybridization; nucleic acid methylation; nucleic acid sequence; nucleic acid structure

During meiosis, after DNA replication, the pairing of chromosomes involves four copies of each chromatid, which synapse together before recombination takes place. Certain short guanine-rich motifs in single-stranded DNA self-recognize and associate in physiological salt to make four-stranded structures in which the strands run in a parallel fashion. Such four-stranded structures, named G4-DNA, are able to crosslink four Watson-Crick duplexes. Such guanine-rich sequences have been found in immunoglobulin switch regions and in the telomeres of chromosomes. It is possible that this self-recognition of G-rich motifs in DNA is used to bring together the four chromatids that must synapse in meiosis, where a series of different G4-DNA-forming regions along the entire length of a chromosome might serve as an identification pattern for pairing. G4-DNA crosslinks may also be used to align chromosomes in mitosis and in the formation of polytene chromosomes. This project will test the hypothesis that G4-DNA-forming regions serve as identification signals for chromosome matching. Anti-G4- DNA antibodies will be used to detect G4-DNA in chromosomes during meiotic pairing. Crosslinks between chromosomes involved in meiotic pairing will be isolated to investigate whether their sequences are such that they can form G4-DNA structures. Such G4- DNA-forming elements and their surrounding sequences will be cloned, and the engagement of guanines into G4-DNA in vivo will be demonstrated by in vivo dimethyl sulfate methylation experiments. The cell may control the formation of G4-DNA at special times in the cell cycle by synthesizing G4-DNA-binding proteins and special DNA melting proteins. Both proteins that recognize G4-DNA and melting proteins that relax the DNA structure in specific regions, in which one strand is unusually G-rich, will be sought. By binding the C-rich strand, such melting proteins would free the G- rich regions to seek each other out from chromatid to chromatid to make crosslinks to bring together four duplexes. The significance of the G4-DNA hypothesis is that it provides an understanding of how chromosome pairing is accomplished throughout eukaryotic organisms and explains why four chromatids are involved in recombination.

在减数分裂过程中，DNA复制后，染色体的配对 涉及每种染色单体的四个副本，它们一起突触 重组之前。 某些短鸟嘌呤丰富 单链DNA自认可和合伙人中的图案 生理盐以制造四链结构 链以平行的方式运行。 这样的四链结构， 名为G4-DNA，能够交叉链接四个Watson-Crick双工。 在免疫球蛋白中发现了这种富含鸟嘌呤的序列 开关区域和染色体的端粒中。 可能 DNA中对G富含G的这种自我识别用于带来 一起必须在减数分裂中突触的四种染色单体 整个沿着一系列不同的G4-DNA形成区域 染色体的长度可能是识别模式 配对。 G4-DNA交叉链接也可用于对齐染色体 在有丝分裂和聚染色体的形成中。 该项目将测试G4-DNA形成区域的假设 用作染色体匹配的识别信号。 抗G4- DNA抗体将用于检测染色体中的G4-DNA 减数分裂配对。 涉及的染色体之间的交联 减数分裂配对将被隔离，以调查他们的 序列使它们可以形成G4-DNA结构。 这样的G4- DNA形成元素及其周围序列将是 克隆的，鸟嘌呤在体内的g4-DNA参与 通过体内二甲基甲基甲基化实验证明。 该单元可能会在特殊时间内控制G4-DNA的形成 通过合成G4-DNA结合蛋白和特殊的细胞周期 DNA熔化蛋白。 识别G4-DNA和 熔化的蛋白质在特定区域放松DNA结构， 其中将寻求一股异常的G充裕。 经过 结合富含C的链，这种熔化的蛋白会释放G- 丰富的区域从染色单体到染色单体互相寻找 进行交联以将四个双工汇总在一起。 G4-DNA假设的重要性是它提供了 了解整个染色体配对的方式 真核生物生物并解释了为什么涉及四个染色单体 重组。