title: Recombination in alphaherpesviruses.
abstract: Within the Herpesviridae family, Alphaherpesvirinae is an extensive subfamily which contains numerous mammalian and avian viruses. Given the low rate of herpesvirus nucleotide substitution, recombination can be seen as an essential evolutionary driving force although it is likely underestimated. Recombination in alphaherpesviruses is intimately linked to DNA replication. Both viral and cellular proteins participate in this recombination-dependent replication. The presence of inverted repeats in the alphaherpesvirus genomes allows segment inversion as a consequence of specific recombination between repeated sequences during DNA replication. High molecular weight intermediates of replication, called concatemers, are the site of early recombination events. The analysis of concatemers from cells coinfected by two distinguishable alphaherpesviruses provides an efficient tool to study recombination without the bias introduced by invisible or non-viable recombinants, and by dominance of a virus over recombinants. Intraspecific recombination frequently occurs between strains of the same alphaherpesvirus species. Interspecific recombination depends on enough sequence similarity to enable recombination between distinct alphaherpesvirus species. The most important prerequisite for successful recombination is coinfection of the individual host by different virus strains or species. Consequently the following factors affecting the distribution of different viruses to shared target cells need to be considered: dose of inoculated virus, time interval between inoculation of the first and the second virus, distance between the marker mutations, genetic homology, virulence and latency. Recombination, by exchanging genomic segments, may modify the virulence of alphaherpesviruses. It must be carefully assessed for the biosafety of antiviral therapy, alphaherpesvirus-based vectors and live attenuated vaccines.
authors.affiliation: Department of Infectious and Parasitic Diseases, Laboratory of Virology and Immunology, Faculty of Veterinary Medicine, University of Liège, Sart-Tilman, Liège, Belgium. etienne.thiry@ulg.ac.be
authors.forename: Etienne
authors.initials: E
authors.lastname: Thiry
authors.forename: François
authors.initials: F
authors.lastname: Meurens
authors.forename: Benoît
authors.initials: B
authors.lastname: Muylkens
authors.forename: Michael
authors.initials: M
authors.lastname: McVoy
authors.forename: Sacha
authors.initials: S
authors.lastname: Gogev
authors.forename: Julien
authors.initials: J
authors.lastname: Thiry
authors.forename: Alain
authors.initials: A
authors.lastname: Vanderplasschen
authors.forename: Alberto
authors.initials: A
authors.lastname: Epstein
authors.forename: Günther
authors.initials: G
authors.lastname: Keil
authors.forename: Frédéric
authors.initials: F
authors.lastname: Schynts
mesh_terms: D018138:Alphaherpesvirinae / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D000818:Animals; D004261:DNA Replication / Q000235:genetics; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D024882:Drug Resistance, Viral / Q000235:genetics; D005822:Genetic Vectors; D016679:Genome, Viral; D006801:Humans; D008957:Models, Genetic; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D012449:Safety; D014765:Viral Vaccines / Q000009:adverse effects / Q000235:genetics; D014774:Virulence / Q000235:genetics
chemical_list: D004279:DNA, Viral; D014765:Viral Vaccines