UMUC 02 AND OH EFFECTS ON GAMMA RADIATION MUTAGENESIS

P.I.的长期目标是确定电离的基础 辐射诱变（Radiation mutagenesis，EMT）。 这个项目是一个早期的修订 提案（1 r 01 CA 55789 - 01 A1），其目标是确定大肠埃希氏菌 colt通过DNA测序分析突变谱[ile.种类及 γ射线诱发的显性lac 1（lacId）突变的位置 （产生约5%存活率的剂量以及不完全诱导 SOS）的影响，各种伽马辐照放气条件下， 突变谱（即N2空气N-）或N2+甘油）氢的影响 γ-辐射突变谱上的过氧化物清除程序 （在细胞外过氧化氢酶存在下的照射和在细胞外过氧化氢酶存在下的照射） oxyR 2，一种导致过氧化氢酶过量产生的突变。等等）：和 各种DNA修复突变对伽马辐射的影响 突变谱（umuC. polB.和第x个第n个NFO三重突变体）。 的 最终目标是试图将特定的突变与特定的种类联系起来 DNA损伤和修复过程。 完成以下工作 具体目标将需要产生大约20个新的lacld突变体。 光谱和大约7000个新突变的测序（已经超过数据） Shannon奖）。 该项目的具体目标是： (1)为了确定umuC依赖性和umuC依赖性的具体性质， 独立辐照（N2下辐照）。以及被认定参与了 DNA聚合酶II在umuC-非依赖性DNA聚合酶（N2下照射）和DNA聚合酶II在DNA聚合酶II中起作用。 DNA聚合酶II在umuC非依赖性 - 是的(2)为了确定由“高浓度”特异性增强的lac 1d水平， 剂量”辐照在O2的存在下，以阐明的具体作用， 无错修复，防止故障，并最终关联O特定 O特异性损伤碱基的修复（3）确定O特异性损伤碱基的作用 γ射线诱发的Laced突变谱细胞的羟自由基 将在N2+甘油（羟基自由基清除剂）下辐照，或 在N2 O（其使羟基自由基的产量加倍并清除 水合电子）与在N2下照射的相同细胞进行比较 并最终尝试将特定的事件与 特定的DNA损伤 (4)为了确定由一种 当SOS修复没有完全激活时， 当它被最大限度地激活时（相同剂量，但使用recA 703 lexA 51苏拉 携带pSE 117的菌株，其携带umuDC基因）。 (5)以确定 在所有四种放气条件下的伽马辐射突变谱 从不可变细胞转移到野生型受体的目标 这样就可以确定诱导突变的受损碱基的身份， 测定并与上面获得的突变谱进行比较。 健康相关性阐明遗传和放射化学基础 电离辐射诱变对于理解 辐射致癌作用

The long term goal of the P.I. is to determine the basis of ionizing radiation mutagenesis (IRM). This project is a REVISION of an earlier proposal (1 r01 CA55789-01A1) and its goal is to determine in Escherichia colt by DNA sequencing analysis the mutational spectrum [ile. the kinds and locations of dominant lac1 (lacId) mutations] induced by gamma-irradiation (doses yielding about 5% survival and also doses that do not fully induce SOS) the effect of various gamma-irradiation gassing conditions on the mutational spectrum (i.e. N2 air N-) or N2+glycerol) the effect of hydrogen peroxide scavenging procedures on the gamma-radiation mutational spectrum (irradiation in the presence of extracellular catalase and the presence of oxyR2, a mutation that causes the overproduction of catalase. , etc.): and the effect of various DNA repair mutations on the gamma-radiation mutational spectrum (umuC. polB. and a xth nth nfo triple mutant). The ultimate goal is to try to associate specific mutations with specific kinds of DNA damage and repair processes. The completion of the following specific aims will require the production of about 20 new lacld mutational spectra and the sequencing of about 7000 new mutations (beyond data already obtained with the Shannon award). The specific aims of this project are; (1) To determine the specific nature of umuC-dependent and umuC- independent IRM (irradiation under N2). and the putative involvement that DNA polymerase II plays in umuC- independent IRM (irradiation under N2) and the putative involvement that DNA polymerase II plays in umuC-independent IRM. (2) To determine the lac1d IRM that is specifically enhanced by "high dose" irradiation in the presence of O2 to elucidate the specific role of error-free repair in preventing IRM and ultimately to associate O specific IRM and repair with O specific damaged bases (3) To determine the role of hydroxyl radicals on gamma-radiation-induced laced mutational spectra cells will be irradiated under N2+ glycerol (a hydroxyl radical scavenger) or under N2O (which doubles the yield of hydroxyl radicals and scavenges hydrated electrons) for comparison with the same cells irradiated under N2 and ultimately an attempt will be made to associate specific IRM with specific DNA damage. (4) To determine mutational spectra induced by a small gamma-radiation dose when SOS repair is not fully activated and also when it is maximally activated (same dose but using a recA703 lexA51 sulA strain carrying pSE117, which carries the umuDC genes). (5) To determine the gamma-radiation mutational spectrum under all four gassing conditions target that is transferred from a nonmutable cell to a wild-type recipient so that the identity of the damaged bases that induce mutations can be determined and compared with mutational spectra obtained above. Health relatedness Elucidation of the genetic and radiochemical bases of ionizing radiation mutagenesis will be valuable towards understanding radiation carcinogenesis.