ABSTRACT
The place of the Leviviridae family, covering two genera Levivirus and Allolevivirus, in the present official taxonomies (ICTV, NCBI) is described, including the recent proclamation of the novel Riboviria realm. The numerous attempts to classify the single-stranded RNA phages by different structural and functional parameters, such as sero- and geno-grouping, affinity to Millipore filters, template specificity of the phage replicases, capability to form hybrid particles, physicochemical properties of the phage RNA and proteins, are compared. The detailed structure of the Leviviridae family is analyzed by possible interconnections with other viral families. The drawbacks of all existing classification and typing systems are pointed out, together with the proposed solutions to improve classification. The chapter presents the most important entries concerning Leviviridae family into prestigious books of references and encyclopedias.
