ANALYSIS OF THE INITIAL EVENTS IN THE IN VIVO REPLICATION OF POLIOVIRUS RNA

脊髓灰质炎病毒神经毒力的减弱似乎是以下因素的结果： 病毒基因组中有限数量的核苷酸变化， 降低病毒的复制效率。 尽管如此， 减毒表型可能是多效性的并且难以分析。 复制效率的差异，特别是对于小核糖核酸病毒， 在病毒感染的最初阶段应该最明显 当感染病毒的基因组启动导致 颠覆细胞。 我们已经证明，低水平的 脊髓灰质炎病毒在感染病毒基因组表达期间的复制 可以通过观察病毒RNA的出现来监测 病毒体RNA（cRNA）。 病毒体RNA的细胞扩增需要cRNA， 其既不存在于病毒体中，也不存在于未感染的细胞中。 极低 使用放射性探针检测和定量cRNA水平 cRNA和从感染周期早期的细胞中纯化的RNA。 这些 研究已经扩展和简化，通过使用 聚合酶链反应（PCR），这是用来描绘 病毒RNA通过病毒的初始阶段的进展 感染

Attenuation of neurovirulence in poliovirus appears to be the results of a finite number of nucleotide changes in the viral genome that cause a decrease in the replicative efficiency of the virus. Despite this, the attenuation phenotype can be pleiotropic and difficult to analyze. Differences in replicative efficiency, especially for picornaviruses, should be most pronounced during the initial stages of viral infection when the infecting viral genome initiates the events that lead to the subversion of the cell. We have demonstrated that the low level of poliovirus replication during the expression of the infecting viral genome can be monitored by following the appearance of viral RNA complementary to virion RNA (cRNA). Cellular amplification of virion RNA requires cRNA, which is found neither in virions nor in uninfected cells. Extremely low levels of cRNA have been detected and quantitated using radioactive probes for cRNA and RNA purified from cells early in the infectious cycle. These studies have been extended and simplified through the use of the polymerase chain reaction (PCR), which is being used to delineate the progression of the viral RNA through the initial stages of viral infection.