IV, 6. Calicivirus RNA recombination.

RNA recombination apparently contributed to the evolution of CVs. Nucleic acid sequence homology or identity and similar RNA secondary structure of CVs and non-CVs may provide a locus for recombination within CVs or with non-CVs should co-infections of the same cell occur. Natural recombinants have been demonstrated among other enteric viruses, including Picornaviridae (Kirkegaard and Baltimore, 1986; Furione et al., 1993), Astroviridae (Walter et al., 2001), and possibly rotaviruses (e.g., Desselberger, 1996; Suzuki et al., 1998), augmenting the natural diversity of these pathogens and complicating viral gastroenteritis prevention strategies based upon traditional vaccines. Such is the case for CVs and Astroviridae, whose recombinant strains may be a common portion of naturally circulating strains. The taxonomic - and perhaps biologic - limits of recombination are defined by the suggested recombination of Nanovirus and CV, viruses from hosts of different biologic orders; the relationship of picornaviruses and CVs, viruses in different families, as recombination partners; and the intra-generic recombination between different clades of NLVs.