The Malacoherpesviridae virus family currently consists of two virus genera with virus species that infect molluscs . Originally the family contained only one genus Ostreavirus with only one virus species, the herpes virus of the Pacific oyster ( Ostreides Herpesvirus 1 , OsHV-1), and was introduced as the third family when the virus order Herpesvirales was created in 2009. Previously, the species was assigned to the Herpesviridae family as an unclassified virus . The name of the family is derived from the ancient Greek μαλακ ( ς ( malakos : soft) or μαλάκιον ( malakion : mollusc ) and means the animal tribe to which the first known host of OsHV-1 belongs, the Pacific rock oyster ( Crassostrea gigas ).
The enveloped virions of the malacoherpesviruses, like all herpesviruses, have an icosahedral capsid ( T = 16 ); in contrast to other herpesviruses, pentons cannot be represented in the capsid. The virions are round to irregular and about 150 to 200 nm in diameter.
Genome
The genome consists of a strand of linear, double-stranded DNA , the open reading frames of which are organized similarly to members of the genus simplex virus and cytomegalovirus in vertebrates. The genome of OsHV-1 is 207,439 bp in size. The genome sequence of the second virus described, the abalone herpesvirus in the genus Aurivirus is not fully released.
