Hughes J V, Johnson T C
J Gen Virol. 1981 Aug;55(Pt 2):53-64. doi: 10.1099/0022-1317-55-2-253.
Six temperature-sensitive (ts) mutants of vesicular stomatitis virus (VSV) isolated from the central nervous system (CNS) following injection with ts G31 (III) all possessed a post-transcriptional defect, not found in the initial virus, that affects the stability of viral RNA transcripts. Examination of viral RNA metabolism in mouse neuroblastoma (N-18) cells revealed that RNA synthesis of the CNS isolates was decreased considerably at elevated temperatures (up to 80 or 90% at 39 degrees C). In addition, analysis of the RNA transcripts suggested that little if any normal-sized transcripts were made in cells infected with these CNS isolates at either 37 degrees C or 39 degrees C. The RNA deficiencies did not appear to be the result of a temperature-sensitive lability of virion transcriptase as examined by in vitro transcriptase assays. However, when N-18 cells infected with one of the CNS isolates, ts G31 BP, were first preincubated at the permissive temperature of 31 degrees C for 3 h and then shifted to 39 degrees C, RNA synthesis proceeded at a rate comparable to that of 31 degrees C. The viral mRNA species synthesized following the temperature shift also contained normal sized tracts of poly(A) RNA, suggesting that neither the viral transcriptase nor its polyadenylate synthetase was thermally labile. However, for any of the six CNS isolates, all species of viral RNA synthesized in cells that were first preincubated at 31 degrees C degraded rapidly when the cells were shifted to 39 degrees C. In contrast little or no RNA degradation of either 42S progeny RNA or mRNA species was detected in the wild-type VSV, ts G31 or three other VSV mutants that are defective in some aspect of viral RNA metabolism: [ts G11 (I), ts G22 (II), ts G41 (IV)]. The apparent phenotype alteration in the stability of viral RNA in all of these CNS isolates is discussed in terms of the possible genotypic changes that may have occurred as well a the unique CNS disease that accompanies infection by these viruses.
在注射ts G31（III）后从中枢神经系统（CNS）分离出的水泡性口炎病毒（VSV）的六个温度敏感（ts）突变体均具有转录后缺陷，这在初始病毒中未发现，该缺陷影响病毒RNA转录本的稳定性。对小鼠神经母细胞瘤（N - 18）细胞中病毒RNA代谢的研究表明，CNS分离株的RNA合成在升高的温度下（39℃时高达80%或90%）显著减少。此外，对RNA转录本的分析表明，在37℃或39℃感染这些CNS分离株的细胞中，几乎没有产生正常大小的转录本。通过体外转录酶测定法检测，RNA缺陷似乎不是病毒粒子转录酶温度敏感不稳定性的结果。然而，当用CNS分离株之一ts G31 BP感染的N - 18细胞首先在允许温度31℃下预孵育3小时，然后转移到39℃时，RNA合成以与31℃相当的速率进行。温度转移后合成的病毒mRNA种类也包含正常大小的聚腺苷酸（poly(A)）RNA片段，这表明病毒转录酶及其聚腺苷酸合成酶都不是热不稳定的。然而，对于这六个CNS分离株中的任何一个，在首先在31℃预孵育的细胞中合成的所有病毒RNA种类，当细胞转移到39℃时都会迅速降解。相比之下，在野生型VSV、ts G31或其他三个在病毒RNA代谢某些方面有缺陷的VSV突变体[ts G11（I）、ts G22（II）、ts G41（IV）]中，未检测到42S子代RNA或mRNA种类的RNA降解。本文根据可能发生的基因型变化以及这些病毒感染所伴随的独特CNS疾病，讨论了所有这些CNS分离株中病毒RNA稳定性的明显表型改变。
