Duggal R, Wimmer E
Department of Molecular Genetics and Microbiology, State University of New York at Stony Brook, Stony Brook, New York, 11794-5222, USA.
Virology. 1999 May 25;258(1):30-41. doi: 10.1006/viro.1999.9703.
Genetic recombination that occurs with high frequency during poliovirus genome replication is a process whose molecular mechanism is poorly understood. Studies of genetic recombination in a cell-free system in vitro and in infected tissue culture cells in vivo have led to the unexpected observation that temperature strongly influences the loci at which cross-over between the two recombining RNA strands occurs. Specifically, cross-over between two genetically marked RNA strands in vitro and in vivo at 34 degrees C occurred over a wide range of the genome. In contrast, recombination in vivo at 37 and 40 degrees C yielded cross-over patterns that had shifted dramatically to a region encoding nonstructural proteins. Preferential selection of recombinants at 37 and 40 degrees C was ruled out by analyses of the growth kinetics of the recombinants. During the studies of recombination in the cell-free system we found that there is a direct correlation between the ability of a poliovirus RNA molecule to replicate in the cell-free system and its capacity to complement de novo virus synthesis programmed by another viral RNA.
脊髓灰质炎病毒基因组复制过程中高频发生的基因重组是一个分子机制尚不清楚的过程。在体外无细胞系统和体内受感染的组织培养细胞中进行的基因重组研究带来了意外发现，即温度会强烈影响两条重组RNA链之间发生交叉的位点。具体而言，在34摄氏度下，两条基因标记的RNA链在体外和体内的交叉发生在基因组的广泛区域。相比之下，在37摄氏度和40摄氏度下体内重组产生的交叉模式已大幅转移至编码非结构蛋白的区域。对重组体生长动力学的分析排除了在37摄氏度和40摄氏度下对重组体的优先选择。在无细胞系统中进行重组研究期间，我们发现脊髓灰质炎病毒RNA分子在无细胞系统中复制的能力与其补充由另一种病毒RNA编程的从头病毒合成的能力之间存在直接关联。
