Ascoviridae Order
Pimascovirales. Members of the family
Ascoviridae come in different shapes. Some can be rod-shaped, while others are oval. They measure up to 130 nm wide and 400 nm long. These viruses have circular double stranded DNA that have a length of about 100–200 kilobase pairs. They infect lepidopteran insect larvae and can infect through parasitoid wasps. Once they infect they replicate and cause death in insect pest. Ascoviridae can have up to 180 genes in its genome. The replication of this virus takes place in the nucleus of the host cell. When it replicates, it causes the nucleus to increase in size and eventually burst. After, the virion starts to form and spread.
Asfarviridae Order
Asfuvirales. A member of the family
Asfarviridae is known as an asfarvirus. This virus is the cause of African swine fever. Some of the symptoms for this flu include fever, high pulse, fast breathing, and it can cause death. These symptoms can be similar to those from hog cholera, the difference is that the African swine flu can not be cured. There is no vaccine developed to fight this virus.
Iridoviridae Order
Pimascovirales. The
Iridoviridae have linear double stranded DNA genomes up to 220 kilobases long and can code for about 211 proteins. The capsid of this virion is icosahedral shaped and can be up to 350 nm wide. The replication cycle of this virus begins in the nucleus of the host and end in the cytoplasm. Some viruses of this family are often found infecting fish and amphibians while other are found in insect and crustaceans. The
Andrias davidianus ranavirus (ADRV), a member of the family
Iridoviridae, encodes a protein (Rad2 homolog) that has a key role in the repair of DNA by
homologous recombination, and in
double-strand break repair.
Marseilleviridae Order
Pimascovirales. The
Marseilleviridae viruses have double stranded DNA genomes that are about 368 kilobases long. Members of the family can have about 457
open reading frames (ORFs) in its genome. The host organisms are
amoebae. Once it infects, viral replication takes place in virus factories in the cytoplasm. It was found that the genome of the family
Marseilleviridae codes for about 28 different proteins. The capsid of the marseillevirus is about 250 nm wide with a geometry shape of an icosahedral. The replication of this virus usually occurs near the nucleus once it infects the amoeba. Once the virus infects it can cause a shape change in the host's nucleus.
Mimiviridae Order
Imitervirales. The
Megaviridae contains some of the largest viruses ever discovered. They have linear double stranded DNA genomes with a length of 1,259,197 base pairs, which is larger than some small bacteria. Within this genome 1,100 proteins are coded. 74.76% of the base pairs are represented by thymine and adenine. The
Megaviridae virus can be found infecting acanthamoeba or other protozoan clades. Once the virus infects the host, the replication cycle takes place in the cytoplasm. Within the genome, DNA repair enzymes can be found. These are used when the DNA is harmed such as when it is exposed to ionizing radiation or UV light. Three enzymes employed in DNA
base excision repair were characterized from Mimivirus. The pathway of DNA base excision repair (BER) was experimentally reconstituted using the purified recombinant proteins
AP endonuclease (mvAPE),
uracil-DNA glycosylase (mvUDG), and
DNA polymerase X protein (mvPolX). Traditionally only these viruses have been grouped into a family
Mimiviridae. Later it appeared that the viruses of the
Organic Lake Phycodna Group (OLPG) are more related to Mimiviruses than to
Phycodnaviruses. For this reason it has been proposed adding them to legacy
Mimiviridae as new subfamily
Mesomimivirinae in order to form the more comprehensive family
Megaviridae. For this reason, the term
Mimiviridae was used
sensu lato synonymous with
Megaviridae. However, since the ICTV has created a new order
Imitervirales officially containing the (legacy)
Mimiviridae, proposed
Mesomimivirinae are proposed to be upgraded as a new family
Mesomimiviridae, i.e. as sister family of legacy
Mimiviridae (within this order).
Pandoraviridae Possibly order
Algavirales.
Pandoraviridae Discovered in 2013 from a coastal water sample in Chile. It is mostly found infecting amoebae. It has a length of 1 micrometer long and .5 micrometer wide. Its genome can be up to 2.5 million base pairs long. The replication of this virus takes place in the cytoplasm. Like other giant viruses, it affects the host's nucleus and can take up to 15 hours to start infecting. Although it is found in water, it does not affect humans, it may actually help us by increasing the production of oxygen in aquatic environments.
Phycodnaviridae Order
Algavirales. The
Phycodnaviridae are icosahedral in shape with a double-stranded DNA molecule. Some members of this family can have a linear double-stranded DNA while others have a circular double stranded DNA. The genome has been found to be up to 560 kilobases in length. Up to 50% of the DNA can be represented by guanine or cytosine. This virus is known to infect algae, which means it is found in the ocean.
Pithoviridae Order
Pimascovirales. The
Pithoviridae have only two known representatives. These viruses infects amoebas and can survive in low temperatures.
Pithovirus sibericum was isolated from permafrost soil from Siberia, where it had remained frozen but viable for more than 30,000 years. This is a double stranded DNA virus with its size being 610 kilobases long. The genome is estimated to code for 467 open reading frames. The viron is rod shaped with a length of 1,100 nm long and 500 nm in diameter.
Poxviridae Order
Chitovirales. The
Poxviridae have a linear double-stranded DNA molecule that can have a length of up to 230 kilobases. The replication of these viruses takes place in the cytoplasm.
Smallpox,
cowpox, and other
pox viruses belong to this family.
Mininucleoviridae (CmV1), Dikerogammarus haemobaphes virus 1 (DhV1), and Panulirus argus virus 1'' (PaV1).
Unclassified taxa •
Cedratvirusnow under
Pithoviridae (
Pimascovirales) •
Choanoviruspart of extended
Mimiviridae, a clade distinct from
Mimiviridae proper; (
Imitervirales) •
Dinodnavirusnow under
Asfarviridae (
Asfuvirales) •
Faustovirusnow under
Asfarviridae (
Asfuvirales) •
Kaumoebavirusclusters under
Asfarviridae (
Asfuvirales) •
Klothovirusno sequences available •
Megaklothovirusno sequences available •
Medusavirusproposed to be its own family
Medusaviridae, possibly close to
Mollivirus or basal in
Nucleocytoviricota •
Meelsvirusno sequences available •
Mollivirusclose to
Pandoravirus (
Algavirales) •
Namao virus(together with
Faunusvirus sp. from metagenomics) close to
Cafeteriavirus; possibly together with other Sturgeon-NCLDVs; (
Imitervirales) •
Orpheoviruslikely under
Pithoviridae; sister group to
Cedratvirus (
Pimascovirales) •
Pacmanviruslikely under
Asfarviridae (
Asfuvirales) •
Platanovirussimilar to
Megavirus or
Tupanvirus (
Imitervirales) •
Sissivirus and
Misannotatedvirus(together with
Solumnvirus,
Solivirus from metagenomics) possibly under
Pithoviridae •
Tupanviruspossibly under
Mimiviridae (
Imitervirales) •
Urceoloviruspossibly under
Nucleocytoviricota •
Usurpativirus and
Clandestinovirusa clade possibly under
Phycodnaviridae nearby
Chlorovirus (
Algavirales) •
Yasminevirusclose to
Klosneuvirus and
Bodo saltans virus; (together with
Gaeavirus,
Homavirus,
Barrevirus,
Fadolivirus,
Dasosvirus,
Edafovirus,
Terrestrivirus,
Harvfovirus,
Hyperionvirus from metagenomics) members of
Mimiviridae (
Imitervirales) ==Phylogenetics==