ANALYSIS OF INTEGRATION MECHANISM OF BACTERIOPHAGE MU

噬菌体Mu具有一种不寻常的重组系统， 成熟噬菌体DNA末端附近的特异性附着位点， 将它们与宿主DHA中明显随机的序列重组。 长 这个项目的范围目标是在分子水平上， 这种重组发生的机制。 这一目标将是 使用以下方法进行：1）λ噬菌体的研究 包含穆的结束将继续通过定义网站， 引起抑制所需的Mu函数和lambda：：mini-Mu 通过分离在允许Mu基因表达的条件下生长 以及缺失和点突变λ：：mini-Mu β的表征。 将尝试新的方法来隔离lambda：：mini-Mu类 包含Mu附着位点紧密相连，并定义为什么这些 在先前的隔离条件下，细菌是不稳定的。 2)的DNA 对Mu整合重要的序列将通过分离和 测序的顺式显性整合缺陷突变体的 λ：：迷你Mu噬菌体。 3)协整与 将研究一个简单的插入mini-Mu来定义载体的作用 DNA复制，Mu溶解基因表达对溶原基因表达的影响， 以及特定Mu基因和宿主基因在插入过程中的作用。 这些研究将大大提高我们对这些遗址的认识， Mu整合中涉及的功能以及整合的过程 发生. 这一信息是重要的，因为它作为一个模型的适用性 为了理解非同源重组过程， 在细菌抗生素耐药性的传播中， 原核生物和真核生物中的自发突变和DNA重排， 定向基因表达和DNA重排的可能应用 发生在真核生物发育过程中，以及致癌基因的整合 病毒 这种过程在正常和异常中的基本作用 增长现在才得到承认，可能在未来产生重大影响。

Bacteriophage Mu possesses an unusual recombination system which recognizes specific attachment sites near the ends of the mature phage DNA and recombines them with apparently random sequences in the host DHA. The long range objective of this project is to understand, at the molecular level, the mechanism by which this recombination occurs. This objective will be pursued using the following approaches: 1) Studies of lambda phages containing the ends of Mu will be continued by defining the sites and functions of Mu which are needed to cause inhibition and lambda::mini-Mu growth under conditions permissive for Mu gene expression through isolation and characterization of deletion and point mutant lambda::mini-Mu phages. New approaches will be tried to isolate the class of lambda::mini-Mu phages containing the Mu attachment sites close together and to define why these phages were unstable under previous isolation conditions. 2) The DNA sequences important for Mu integration will be defined by isolating and sequencing cis-dominant integration-defective mutants of the lambda::mini-Mu phage. 3) The relative frequency of cointegrate versus simple insertion of mini-Mu will be studied to define the role of vector DNA replication, the effects of Mu lytic versus lysogenic gene expression, and the roles of specific Mu and host genes in the insertion process. These studies will significantly advance our knowledge of the sites and functions involved in Mu integration and the process by which integation occur. This information is important due to its applicability as a model for understanding non-homologous recombination processes which are involved in the spread of antibiotic resistance in bacteria, generation of spontaneous mutations and DNA rearrangements in procarvotes and eucaryotes, possible application to directed gene expression and DNA rearrangement occuring during development in eucaryotes, and the integration of oncogenic viruses. The fundamental role of such processes in normal and abnormal growth is now only being recognized and may have great impact in the future.