title: Genetic recombination of poliovirus in vitro and in vivo: temperature-dependent alteration of crossover sites.
abstract: 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.
mesh_terms: D001665:Binding Sites; D002474:Cell-Free System; D003434:Crossing Over, Genetic; D005816:Genetic Complementation Test; D005819:Genetic Markers; D014644:Genetic Variation; D006367:HeLa Cells; D006801:Humans; D017955:Poliovirus / Q000235:genetics* / Q000254:growth & development; D012367:RNA, Viral / Q000096:biosynthesis; D011995:Recombination, Genetic; D013696:Temperature