GENE REGULATION OF MAMMALIAN DNA VIRUSES

我们计划对一系列兔白斑宿主范围突变体进行详细研究 痘病毒(RPMu突变体)在不允许的细胞中在许多阶段被阻止 病毒的发展。作为一项重大努力，我们计划继续我们的测绘工作 对这些突变体的研究，我们已经证明这是缺失的结果，通过 使用限制性内切酶分析。我们对五个突变体的研究 已经检查出宿主范围内17%的病毒基因组 现象线虫。我们的数据显示，这五个突变导致了三个不同的 非允许细胞中的表型，提供了关联的可能性 基因组中特定功能的特定区域。作为这方面的一个步骤 方向，我们计划将剩余的15个寄主范围RPmu突变体映射到我们的 收集并描述它们的特征，如在合成和 大分子的处理在不允许的宿主中被阻止，以及原因。我们 还计划将我们的基因图谱研究扩展到包括一系列“白色”基因 非寄主范围的突变体，也可能缺失，这是因为它们很容易 与寄主范围突变体的重组，应该位于基因组的其他地方。我们 已经对两个突变体进行了生化鉴定，这些突变体似乎被阻止了 在翻译层面上。我们建议研究这一现象的机制 详细的翻译块。另外三个突变体在水平上被阻止 形态发生，并合成了不同于 彼此之间。我们计划通过生物物理学和生物化学的方法来表征这些反常粒子 电子显微镜方法以及病毒粒子相关酶的测定 活动。因为寄主范围突变体的存在反映了生化 细胞之间的差异，我们希望利用我们的信息开始探索 这些差异允许选择性地侵入目标器官和 体内的组织，并导致与给定病毒相关的疾病状态 感染。

We plan to study in detail a series of "white pock" host range mutants of rabbit poxvirus (RPmu mutants) which in nonpermissive cells are blocked at many stages of viral development. As a major effort, we plan to continue our mapping studies on these mutants, which we have shown to be the result of deletions, by the use of restriction enzyme analysis. Our studies on the five mutants that we have examined have already implicated 17% of the viral genome in the host range phenonema. Our data show that these five mutants result in three different phenotypes in nonpermissive cells, offering the possiblity of correlating defined regions of the genome to a specific function. As a step in this direction, we plan to map the remaining 15 host range RPmu mutants in our collection and characterize them as to what steps in the synthesis and processing of macromolecules are blocked in the nonpermissive host and why. We also plan to extend our genetic mapping studies to include a series of "white pock" nonhost range mutants, also probably deletions, which because they readily recombine with the host range mutants, should lie elsewhere on the genome. We have already biochemically characterized two mutants which appear to be blocked at the level of translation. We propose to study the mechanism of this translation block in detail. Three additional mutants are blocked at the level of morphogenesis, and synthesized aberrant virus-like particles different from one another. We plan to characterize the aberrant particles by biophysical and electron microsopic means, as well as by assay of virion-associated enzymatic activities. Since the existence of host range mutants reflects biochemical differances between cells, we hope to use our information to begin to explore these differences which allow the selective invasion of target organs and tissues in vivo and lead to the disease state asociated with a given viral infection.