High-frequency RNA recombination of murine coronaviruses

Abstract

The RNA genome of coronaviruses consists of a single species of nonsegmented RNA. In this communication, we demonstrate that the RNA genomes of different strains of murine coronaviruses recombine during mixed infection at a very high frequency. Susceptible cells were coinfected with a temperature-sensitive mutant of one

An update on canine coronaviruses: Viral evolution and pathobiology

“…Another important mechanism for CoV genetic evolution is the high frequency of homologous RNA recombination (Lai et al, 1985;Makino et al, 1986). This process is believed to be mediated by a ''copychoice'' mechanism (Cooper et al, 1974;Kirkegaard and Baltimore, 1986;Makino et al, 1986).…”

“…Another important mechanism for CoV genetic evolution is the high frequency of homologous RNA recombination (Lai et al, 1985;Makino et al, 1986). This process is believed to be mediated by a ''copychoice'' mechanism (Cooper et al, 1974;Kirkegaard and Baltimore, 1986;Makino et al, 1986). Recombination of CoV genomes has been observed during growth in tissue cultures (Lai et al, 1985;Makino et al, 1986;Sanchez et al, 1999;Kuo et al, 2000), in experimentally infected animals (Keck et al, 1988), and in embryonated eggs (Kottier et al, 1995).…”

Evolution of infectious bronchitis virus in Taiwan: Characterisation of RNA recombination in the nucleocapsid gene

“…Nevertheless, as the restraint of error threshold of lethal mutations, the coronavirus is speculated to have a relatively low mutation rate due to its large genome size (Eigen, 1987;Maynard Smith and Szathmá ry, 1995). To increase viral adaptability and fitness, coronavirus has evolved a unique discontinuous transcription system and 'copy-choice' genomic synthesis to achieve high efficiency of RNA recombination (Cavanagh, 2007;Lai et al, 1985;Liao and Lai, 1992;Makino et al, 1986). However, only sporadic recombinant variants have been detected in nature.…”

“…In addition to point mutation, RNA recombination is also involved in the generation of new antigenic variants. RNA recombination in a coronavirus was first demonstrated experimentally in mouse hepatitis virus (MHV) (Lai et al, 1985;Makino et al, 1986), and a high frequency of recombination was found both in vitro and in vivo after MHV infection (Keck et al, 1988;Makino et al, 1986). Recombination sites were detected throughout nearly the entire genome, and many recombinants with multiple crossover sites were found (Liao and Lai, 1992).…”

“…Recombination sites were detected throughout nearly the entire genome, and many recombinants with multiple crossover sites were found (Liao and Lai, 1992). The high frequency of RNA recombination in coronaviruses is likely caused by the unique mechanism of RNA synthesis, which involves discontinuous transcription and polymerase jumping (Cavanagh, 2007;Lai et al, 1985;Liao and Lai, 1992;Makino et al, 1986). Putative IBV genetic recombination in the S gene has been documented in different field isolates, including a Japanese strain (KB8523), European Avian infectious bronchitis virus (IBV) belongs to the Coronaviridae family and causes significant economic loss in Taiwan (TW), even in flocks that have been extensively immunised with Massachusetts (Mass)-serotype vaccines.…”