The family Closteroviridae revised

Molecular and biological information has prompted the revision of the taxonomic structure of the family Closteroviridae. In particular, mealybug-transmitted species have been separated from the genus Closterovirus and accommodated in a new genus named Ampelovirus (from ampelos, Greek for grapevine). Thus, the familynow comprises three genera. Their major properties are (i) Closterovirus: type species Beetyellows virus, genome monopartite, 15.5–19.3 kb in size, a 22–25 kDa major coat protein(CP), the gene encoding the divergent CP analogue (CPd) upstream of the CP cistron, transmission by aphids, a membership of 8 definitive and 4 tentative species; (ii) Ampelo-virus:type species Grapevine leafroll virus 3, genome monopartite 16.9–19.5 kb in size,a 35–37 kDa major CP, a CPd cistron generally located downstream of the CP gene,transmission by pseudococcid and coccid mealybugs, a membership of 6 definitive and 5 tentative species; (iii) Crinivirus: type species Lettuce infectious yellows virus, genome essentially bipartite 15.3–19 kb in size, a 28–33 kDa CP, a CPd cistron downstream of the CP gene, transmission by whiteflies (Bemisia, Trialeurodes), a membership of 7 definitive and 3 tentative species. There are five unassigned species in the family.