DNA SEQUENCE CHARACTERIZATION OF BACTERIOPHAGE T4 RII MUTATIONS

我们正在使用噬菌体T4 RII系统作为模型来探索 DNA损伤和突变的机制。因为传统的DNA 分析RII基因突变分子性质的测序方法有 费力又慢，我们正在开发基于基因组测序的方法。 使用这种方法，重要的突变类别将被检查其 序列发生了变化。例如，即使是轻微的高温也会破坏DNA，如果 没有修复，每个二倍体人类细胞产生大约100个突变 一天。早期的研究表明，热既会引起转变，也会导致 噬菌体T4中G：C碱基对的转换。基因研究表明 热诱导的易位途径主要是G：C到C：G，但不是 排除G：C到T：A。我们已经证明，实际的错配 热损伤鸟嘌呤(G*)是G*：A。这项工作现已出版， 项目已经完成。

We are using the bacteriophage T4 rII system as a model to explore mechanisms of DNA damage and mutagenesis. Because traditional DNA sequencing methods for analyzing the molecular nature of rII mutations are laborious and slow, we are developing methods based on genomic sequencing. With this method, important classes of mutations will be examined for their sequence changes. For instance, even mild heat damages DNA and could, if not repaired, produce on the order of 100 mutations per diploid human cell per day. Earlier studies showed that heat induces both transitions and transversions at G:C base pairs in phage T4. Genetic studies suggested that the main heat-induced transversion pathway is G:C to C:G but did not exclude G:C to T:A. We have shown that the actual mispairing of heat-damaged guanine (G*) Is G*:A. This work has now been published and the project is completed.