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 病毒基因组中有限数量的核苷酸变化会导致 病毒的复制效率下降。尽管如此， 衰减表型可能是多效性的，很难分析。 复制效率的差异，特别是对小核糖核酸病毒， 应该在病毒感染的最初阶段最为明显 当感染的病毒基因组启动导致 颠覆单元格。我们已经证明，低水平的 感染病毒基因组表达过程中脊髓灰质炎病毒的复制 可以通过跟随病毒RNA的出现来监测 病毒粒子RNA(CRNA)。病毒粒子RNA的细胞扩增需要cRNA， 它既不存在于病毒粒子中，也不存在于未感染的细胞中。极低 已使用放射性探针检测和定量了cna的水平。 用于在感染周期早期从细胞中纯化的cRNA和RNA。这些 研究已通过使用 聚合酶链式反应(PCR)，这是用来描绘 病毒RNA在病毒早期阶段的研究进展 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.