The taxonomy of herpesviruses has been updated by the International Committee on Taxonomy of Viruses (ICTV). The former family Herpesviridae has been split into three families, which have been incorporated into the new order Herpesvirales. The revised family Herpesviridae retains the mammal, bird and reptile viruses, the new family Alloherpesviridae incorporates the fish and frog viruses, and the new family Malacoherpesviridae contains a bivalve virus. Three new genera have been created in the family Herpesviridae, namely Proboscivirus in the subfamily Betaherpesvirinae and Macavirus and Percavirus in the subfamily Gammaherpesvirinae. These genera have been formed by the transfer of species from established genera and the erection of new species, and other new species have been added to some of the established genera. In addition, the names of some nonhuman primate virus species have been changed. The family Alloherpesviridae has been populated by transfer of the genus Ictalurivirus and addition of the new species Cyprinid herpesvirus 3. The family Malacoherpesviridae incorporates the new genus Ostreavirus containing the new species Ostreid herpesvirus 1.
The classification of herpesviruses has been updated as a result of recommendations made to the International Committee on Taxonomy of Viruses (ICTV; http://www.ictvonline.org) by the Herpesviridae Study Group as it was constituted in the period 2002–2005. The purpose of this report is to convey the taxonomic changes.
Morphologically, herpesviruses are distinct from all other viruses. A linear, double-stranded DNA genome of 125–290 kbp is contained within a T = 16 icosahedral capsid, which is surrounded by a proteinaceous matrix dubbed the tegument and then by a lipid envelope containing membrane-associated proteins . Genetically, herpesviruses fall into three distinct groupings that are related only tenuously to each other [4, 5, 7]. These groupings consist of viruses of mammals, birds and reptiles, viruses of fish and frogs, and a single virus of bivalves. Of the few proteins that are detectably conserved in sequence among the three groupings, none has homologues that are found only in herpesviruses. The protein that comes nearest to being herpesvirus-specific is the putative ATPase subunit of the terminase (a complex that is responsible for packaging virus DNA into nascent capsids), which is conserved in all herpesviruses and, to a lesser degree, T4-like bacteriophages in the family Myoviridae. The taxonomic outcome of the apparently large genetic distances among the groupings is that the former family Herpesviridae , which contained all herpesviruses, has now been divided into three families that comprise the new order Herpesvirales. The revised family Herpesviridae retains the viruses of mammals, birds and reptiles, the new family Alloherpesviridae (from ἄλλος—other, different) incorporates the fish and frog viruses, and the new family Malacoherpesviridae (from μαλακός—soft; μαλάκιον—mollusc) contains the bivalve virus. The revised classification is shown in Table 1.
Three new genera have been created in the family Herpesviridae. One is the genus Proboscivirus (from προβoσκίς or proboscis: elephant’s trunk), which recognizes a distinct lineage of the subfamily Betaherpesvirinae containing the new species Elephantid herpesvirus 1 [9, 16, 19]. The others are the genera Macavirus (sigla from malignant catarrhal fever) and Percavirus (sigla from perissodactyl and carnivore), which form two lineages in the subfamily Gammaherpesvirinae that are separable from the established genera [14, 15]. The genus Macavirus contains the established species Alcelaphine herpesvirus 1, Alcelaphine herpesvirus 2, Hippotragine herpesvirus 1 and Ovine herpesvirus 2, which were transferred from the genus Rhadinovirus, plus the new species Bovine herpesvirus 6, Caprine herpesvirus 2, Suid herpesvirus 3, Suid herpesvirus 4 and Suid herpesvirus 5 [1, 2, 23]. The genus Percavirus contains the established species Equid herpesvirus 2, Equid herpesvirus 5 and Mustelid herpesvirus 1, which were also transferred from the genus Rhadinovirus. Other new species include Columbid herpesvirus 1 and Psittacid herpesvirus 1 in the genera Mardivirus and Iltovirus, respectively, of the subfamily Alphaherpesvirinae [8, 22]. In addition, several new species were classified at the level of subfamily or family, with assignment to genera awaiting further data. These include the reptilian species Chelonid herpesvirus 5 and Chelonid herpesvirus 6 in the subfamily Alphaherpesvirinae [3, 11, 13, 17, 26], Phocid herpesvirus 2 in the subfamily Gammaherpesvirinae [10, 12], and Iguanid herpesvirus 2 in the family Herpesviridae [13, 25].
Herpesvirus species are named after a taxon of the host that in its natural setting harbours the virus [20, 21]. The default host taxon employed is that of family, and, except for the species of humans, the name ends in ‘-id’. Owing to their larger numbers, species from nonhuman primates and the family Bovidae have been designated by host subfamily, with the name ending in ‘-ine’. In the revised taxonomy, species from nonhuman primates have been renamed by host genus, with the name again ending in ‘-ine’. This has resulted in name changes for several Old World and one New World nonhuman primate herpesvirus species, and has reduced the very large number of species that previously incorporated the Cercopithecine prefix. The new names are correlated to the former names in Table 1.
The established genus Ictalurivirus has been transferred to the family Alloherpesviridae, and the new species Cyprinid herpesvirus 3 been added to the family . The new genus Ostreavirus (from ὄστρεον or ostrea—oyster) has been created in the family Malacoherpesviridae, containing the single known species of an invertebrate host, Ostreid herpesvirus 1 .
The need to balance logic and utility makes taxonomy a challenging process, and matters are often not straightforward. In addition to keeping abreast of new viruses as they are discovered, current discussions in the Herpesviridae (now Herpesvirales) Study Group (chaired by P.E. Pellett) include updating the herpesvirus species definition and the methods used for taxonomic assignment, in order to accommodate the well-established value of sequence-based phylogenetic relationships, and defining a pathway to species status for the large and increasing number of herpesviruses that have been detected only by PCR.
Chmielewicz B, Goltz M, Ehlers B (2001) Detection and multigenic characterization of a novel gammaherpesvirus in goats. Virus Res 75:87–94
Chmielewicz B, Goltz M, Franz T, Bauer C, Brema S, Ellerbrok H, Beckmann S, Rziha HJ, Lahrmann KH, Romero C, Ehlers B (2003) A novel porcine gammaherpesvirus. Virology 308:317–329
Coberley SS, Condit RC, Herbst LH, Klein PA (2002) Identification and expression of immunogenic proteins of a disease-associated marine turtle herpesvirus. J Virol 76:10553–10558
Davison AJ (1992) Channel catfish virus: a new type of herpesvirus. Virology 186:9–14
Davison AJ (2002) Evolution of the herpesviruses. Vet Microbiol 86:69–88
Davison A, Eberle R, Hayward GS, McGeoch DJ, Minson AC, Pellett PE, Roizman B, Studdert MJ, Thiry E (2005) Herpesviridae. In: Fauquet CM, Mayo MA, Maniloff J, Desselberger U, Ball LA (eds) Virus taxonomy, classification and nomenclature of viruses, eighth report of the International Committee on the Taxonomy of Viruses. Elsevier Academic Press, London, pp 193–212
Davison AJ, Trus B, Cheng N, Steven AC, Watson MS, Cunningham C, Le Deuff RM, Renault T (2005) A novel class of herpesvirus with bivalve hosts. J Gen Virol 86:41–53
Ehlers B, Borchers K, Grund C, Frölich K, Ludwig H, Buhk HJ (1999) Detection of new DNA polymerase genes of known and potentially novel herpesviruses by PCR with degenerate and deoxyinosine-substituted primers. Virus Genes 18:211–220
Ehlers B, Burkhardt S, Goltz M, Bergmann V, Ochs A, Weiler H, Hentschke J (2001) Genetic and ultrastructural characterization of a European isolate of the fatal endotheliotropic elephant herpesvirus. J Gen Virol 82:475–482
Harder TC, Harder M, Vos H, Kulonen K, Kennedy-Stoskopf S, Liess B, Appel MJ, Osterhaus AD (1996) Characterization of phocid herpesvirus-1 and -2 as putative alpha- and gammaherpesviruses of North American and European pinnipeds. J Gen Virol 77:27–35
Herbst L, Ene A, Su M, Desalle R, Lenz J (2004) Tumor outbreaks in marine turtles are not due to recent herpesvirus mutations. Curr Biol 14:R697–R699
Martina BE, Verjans GM, Harder TC, Kuiken T, van de Bildt MW, van Bergen PA, Osterhaus AD (2003) Seal gammaherpesviruses: identification, characterisation and epidemiology. Virus Res 94:25–31
McGeoch DJ, Gatherer D (2005) Integrating reptilian herpesviruses into the family Herpesviridae. J Virol 79:725–731
McGeoch DJ, Dolan A, Ralph AC (2000) Toward a comprehensive phylogeny for mammalian and avian herpesviruses. J Virol 74:10401–10406
McGeoch DJ, Gatherer D, Dolan A (2005) On phylogenetic relationships among major lineages of the Gammaherpesvirinae. J Gen Virol 86:307–316
McGeoch DJ, Rixon FJ, Davison AJ (2006) Topics in herpesvirus genomics and evolution. Virus Res 117:90–104
Nigro O, Yu G, Aguirre AA, Lu Y (2004) Sequencing and characterization of the full-length gene encoding the single-stranded DNA binding protein of a novel Chelonian herpesvirus. Arch Virol 149:337–347
Pellett PE, Roizman B (2006) The Herpesviridae: a brief introduction. In: Knipe DM, Howley PM, Griffin DE, Lamb RA, Martin MA, Roizman B, Straus SE (eds) Fields virology, 5th edn. Lippincott, Williams & Wilkins, Philadelphia, pp 2479–2499
Richman LK, Montali RJ, Garber RL, Kennedy MA, Lehnhardt J, Hildebrandt T, Schmitt D, Hardy D, Alcendor DJ, Hayward GS (1999) Novel endotheliotropic herpesviruses fatal for Asian and African elephants. Science 283:1171–1176
Roizman B, Carmichael LE, Deinhardt F, de-The G, Nahmias AJ, Plowright W, Rapp F, Sheldrick P, Takahashi M, Wolf K (1981) Herpesviridae. Definition, provisional nomenclature, and taxonomy. Intervirology 16:201–217
Roizman B, Desrosiers RC, Fleckenstein B, Lopez C, Minson AC, Studdert MJ (1992) The family Herpesviridae: an update. Arch Virol 123:425–449
Thureen DR, Keeler CL Jr (2006) Psittacid herpesvirus 1 and infectious laryngotracheitis virus: comparative genome sequence analysis of two avian alphaherpesviruses. J Virol 80:7863–7872
Ulrich S, Goltz M, Ehlers B (1999) Characterization of the DNA polymerase loci of the novel porcine lymphotropic herpesviruses 1 and 2 in domestic and feral pigs. J Gen Virol 80:3199–3205
Waltzek TB, Kelley GO, Stone DM, Way K, Hanson L, Fukuda H, Hirono I, Aoki T, Davison AJ, Hedrick RP (2005) Koi herpesvirus represents a third cyprinid herpesvirus (CyHV-3) in the family Herpesviridae. J Gen Virol 86:1659–1667
Wellehan JFX, Jarchow JL, Reggiardo C, Jacobson ER (2003) A novel herpesvirus associated with hepatic necrosis in a San Esteban chuckwalla, Sauromalus varius. J Herpetol Med Surg 13:15–19
Yu Q, Hu N, Lu Y, Nerurkar VR, Yanagihara R (2001) Rapid acquisition of entire DNA polymerase gene of a novel herpesvirus from green turtle fibropapilloma by a genomic walking technique. J Virol Methods 91:183–195
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Davison, A.J., Eberle, R., Ehlers, B. et al. The order Herpesvirales . Arch Virol 154, 171–177 (2009). https://doi.org/10.1007/s00705-008-0278-4
- Established Genus
- Frog Virus
- Established Species
- Malignant Catarrhal Fever
- Equid Herpesvirus