FACTORS AFFECTING SOMATIC MUTATION--FOCUS ON THE BRAIN

我们的工作和其他人的工作强烈表明，内生过程 而不是环境中的外源诱变剂调节大多数生殖系 突变。内源性过程也可能产生大部分突变。 与某些类型的癌症有关。然而，像这样的非分割单元 作为神经元，对癌症不敏感。自发的躯体 突变对这些组织有什么重要影响吗？长期的 这个项目的目标是检验假设，细胞死亡是由于 自发性增强的体细胞突变是 利用新开发的转基因小鼠研究神经退行性疾病 突变检测系统(Big Blue(TM))。大蓝鼠携带大肠杆菌 Lambda噬菌体序列中的LacI基因，该基因整合到 小鼠基因组。可以从小鼠身上分离LacI基因的突变 通过与Lambda包装提取液孵育基因组DNA和感染 大肠埃希菌。使LacI基因失活的突变会产生蓝色斑块 它们可以被分离和分析。在这个系统中，突变频率 将确定大脑五个区域的模式，并将其进行比较 其他体细胞和生殖系的Wi突变频率和模式 纸巾。该项目的具体目标是： 1)确定组织/细胞类型、性别、年龄或有丝分裂活动是否会影响 小鼠的突变模式。 2)确定大脑的不同区域是否有不同的模式 突变。 3)确定存在缺陷的转基因小鼠的突变模式 DNA修复。 4)确定过表达转基因小鼠的突变模式 突变和正常的超氧化物歧化酶1。 5)确定噬菌体整合部位和啮齿动物种类对 突变的模式。

Our work and that of others strongly suggests that endogenous processes rather than exogenous mutagens in the environment mediate most germline mutations. Endogenous processes may also produce most of the mutations associated with certain types of cancer. However, non-dividing cells such as neurons, are no susceptible to cancer. Does spontaneous somatic mutation have any important consequences in these tissues? The long-term objective of this project is to test the hypothesis that cell death due to increased-spontaneous somatic mutation is an important substrate for neurodegenerative disorders by using a newly developed transgenic mouse mutation detection system (Big Blue (TM)). Big Blue mice carry the E. coli lacI gene within a lambda phage sequence which is integrated into the mouse genome. Mutations in the lacI gene can be isolated from mouse genomic DNA by incubation with lambda packaging extract and infection of E. coli. Mutations that inactivate the lacI gene produce blue plaques which can be isolated and analyzed. With this system, mutation frequencies and patterns will be determined for five regions of the brain and compared wi mutation frequencies and patterns of other somatic and germline tissues. The specific aims of the project are: 1) Determine if tissue/cell type, gender, age, or mitotic activity affect the pattern of mutation in mouse. 2) Determine if different regions of the brain have different patterns of mutation. 3) Determine the pattern of mutation in transgenic mice with defects in DNA repair. 4) Determine the pattern of mutation in transgenic mice with overexpressed mutated and norma superoxide dismutase 1. 5)Determine the effects of phage integration site and rodent species on the pattern of mutation.