DNA SEQUENCING OF UV-INDUCED CHROMOSOMAL MUTATIONS

紫外线诱导的染色体突变的 DNA 测序

• 批准号: 2176775
• 负责人: Christopher W Lawrence
• 金额: $ 19.5万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-12-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2176775
• 关键词: DNA damage; DNA repair; Escherichia coli; bacterial genetics; cancer risk; chromosome aberrations; double stranded RNA; environment related neoplasm /cancer; gene deletion mutation; genetic manipulation; genetic recombination; lac operon; nucleic acid sequence; ozone; plasmids; pyrimidines; radiation carcinogen; regulatory gene; ultraviolet radiation

The long term goal of the proposed work is to understand the molecular biological and biophysical processes that lead to the production of mutations when mutagen-damaged DNA is replicated. This proposal aims to exploit the analytical power of experiments with vectors that carry a single defined and specifically located UV photoproduct. These tools will be used (i) to investigate the question of how DNA photoproduct structure is related to its mutagenic properties, (ii) to analyze the different components of the spectrum of UV-induced mutations, and attempt to reconstruct this spectrum from its component parts, (iii) to determine whether double-stranded DNA provides opportunities for error-free bypass of lesions, in addition to error-prone translesion replication, and (iv) to explore and define the roles of various normal and mutant genes in bypass and mutagenesis. These studies are likely to advance our understanding of UV mutagenesis, and of mutagenic mechanisms in general. UV is a significant environmental carcinogen, one that is likely to become of even greater importance in the future because of ozone depletion in the upper atmosphere, and mutagenesis is an important step in cancerogenesis. A better understanding of mutagenic mechanisms will help in estimating health risks from carcinogens, particularly in the difficult issues of extrapolation from high acute to low chronic doses, and from one species to another. The experimental design for this proposal is to construct vectors that carry a single uniquely placed mutagenic photoproduct, and determine the properties of the lesion when the vector is replicated in vivo. Estimates will be made of the three basic parameters that define a lesion's mutagenic potential: frequency of bypass, error-frequency of bypass, and mutation spectrum. A variety of photoproducts will be examined, and also a variety of vectors, including both single- and double-stranded constructs. Photoproducts to be studied include cis-syn and trans-syn cyclobutane dimers, and both the normal and dewar isomers of pyrimidine (6-4) pyrimidone adducts, each located in a variety of bipyrimidine target sites, and flanked by a variety of different nucleotides.

这项拟议工作的长期目标是理解分子 导致生产的生物和生物物理过程 当突变剂损坏的DNA被复制时的突变。这项建议旨在 利用实验的分析能力，使用携带 单一定义和特定位置的UV感光产品。这些工具将 用来研究DNA光产物的结构问题 与其致突变性有关，(Ii)分析不同 紫外线诱导突变的光谱成分，并试图 从其组成部分重建该光谱，(Iii)确定 双链DNA是否提供了无差错绕过的机会 病变，以及容易出错的跨病变复制，以及(四)至 探索和确定各种正常和突变基因在旁路中的作用 和诱变。 这些研究可能会促进我们对紫外线诱变的理解， 以及总体上的诱变机制。紫外线是一种重要的环境 致癌物，一种很可能变得更加重要的 未来是因为高层大气中的臭氧消耗和诱变 是癌变过程中的重要一步。更好地理解 诱变机制将有助于评估致癌物的健康风险， 特别是在从高到尖锐的外推的困难问题上 低长期剂量，从一个物种到另一个物种。 该方案的实验设计是构建 携带单一的唯一放置的诱变照相产品，并确定 当载体在体内复制时，损伤的性质。估计数 将由定义病变诱变性的三个基本参数组成 潜在：旁路频率、旁路错误频率和突变 频谱。各种各样的照相产品将被检查，也有各种各样的 包括单链和双链构建物。 拟研究的光产物包括顺式环丁烷和反式环丁烷 二聚体，以及嘧啶的正常异构体和杜瓦异构体(6-4) 嘧啶加合物，每个位于不同的联嘧啶靶点， 两侧是各种不同的核苷酸。