REPLICATION OF DNA IN EUCARYOTES

我们有两个短期目标。 首先，我们希望开发的方法， 将允许电子显微镜研究复制在缓慢分裂 真核细胞 将使用几种方法来富集可复制的 生长点，每种方法将利用不同的特性 这些DNA片段的特性。 这些程序将允许直接 电镜观察正常和 异常生长的真核细胞 我们的第二个目标是获得新的 关于真核生物复制过程的信息。 最初我们 将研究黑腹果蝇快速分裂的卵裂核 （其不需要上述富集程序）和D. melanogaster和HeLa细胞系（需要富集）。 的 短期目标是检查咖啡因，ara-A，ara-C， 苯并（a）芘代谢产物和溴尿苷对复制机制的影响。 对咖啡因的初步实验表明，这种药物可以放松大脑， 控制噬菌体λ复制子中的再起始，因此 重要的是要确定它是否也干扰了已知的类似控制系统， 存在于真核生物中。 我们的长期目标是了解 启动、方向性和终止被控制在正常和 异常生长的细胞 实现这一目标的一个重要途径是 研究各种药物如何干扰复制过程。 的理解 这些区域对于更好地掌握DNA功能是绝对必要的 在正常和异常生长，病毒感染和诱变。

We have two major short-term goals. First, we wish to develop methods that will allow an electron microscopic study of replication in slowly dividing eucaryote cells. Several methods will be used to enrich for replicative growing points, each method will exploit a different characteristic property of these DNA segments. These procedures will allow a direct electron microscopic study of replicating growing points in normal and abnormally growing eucaryote cells. Our second aim is to obtain new information about the process of replication in eucaryotes. Initially we will study the rapidly dividing cleavage nuclei of Drosophila melanogaster (which will not require the above enrichment procedures) and D. melanogaster and HeLa cell lines (which will require enrichment). The short-term goal is to examine the effect of caffeine, ara-A, ara-C, benzo(a)pyrene metabolites and bromouridine onthe replication mechanism. Preliminary experiments with caffeine have shown that this drug relaxes the control of reinitiation in the phage lambda replicator and it is therefore important to determine if it also disturbs similar control systems known to exist in eucaryotes. Our long-term objective is to understand how initiation, directionality and termination are controlled in normal and abnormally growing cells. One important way to obtain this goal is to study how various drugs disturb the replication process. An understanding of these areas is absolutely essential for a firmer grasp of DNA function in normal and abnormal growth, virus infection and mutagenesis.