Teschovirus
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The Teschovirus is a genus of the Picornaviridae family. This virus is responsible for the porcine enteroviral encephalomyelitis disease caused in pigs [1]. The Teschen disease which gave the name to the particular virus is a severe and fatal form of pig encephalomyelitis. The species that causes these diseases is called Porcine Teschovirus and is the type species of the Teschovirus genus. The causative agent of these two diseases was thought to belong to the Enterovirus genus but it is now proved that it belongs to the discrete Teschovirus genus [1].
Teschovirus has a single stranded linear and non segmented RNA genome. The RNA genome is positively sensed meaning that it has the same polarity as the mRNA and no reverse transcription is necessary. It doesn’t have a segmented genome. The size of the genome is between 7000 to 9000 nucleotides long [2]. In addition the virus genome contains at the 5’ end a protein called VPg and the 3’ end is polyadenylated [3]. Through translation of the genome a polyprotein is produced. It is later cleaved in order to give twelve proteins. These proteins are nucleoproteins, non-structural proteins, a polymerase, proteases like the leader protein and the genome linked-protein [3].
The icosahedral symmetry characterizes the Teschovirus capsid. This virus has no envelope and the general size of the particles is around 30nm in diameter.
[edit] References
[1] http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/102100.htm
[2] http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/00.052.0.09.htm
[3] http://www.dpvweb.net/notes/showgenus.php?genus=Teschovirus