Cedratvirus

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' Cedratvirus'
Systematics
Classification : Viruses
Area : Varidnaviria
Empire : Bamfordvirae
Phylum : Nucleocytoviricota
Class : Megaviricetes
Order : Pimascovirales
Family : " Pithoviridae "
Genre : "Cedratvirus"
Taxonomic characteristics
Genome : dsDNA circular
Baltimore : Group 1
Symmetry : available
Scientific name
"Cedratvirus"
Left
NCBI  Taxonomy: Cedratvirus (all) ,
1903266 (A11)

" Cedratvirus " is a proposed genus of giant viruses from the Pithoviridae family with egg-shaped virus particles (virions), which has not yet been officially confirmed by the International Committee on Taxonomy of Viruses (ICTV ). " Cedratvirus " differs from other pithoviruses in that it has a two-layer envelope membrane.

The first known representative of this genus, the species Cedratvirus A11 , was described in 2016 by Julien Andrean and colleagues during the joint cultivation of amoebas of the species Acanthamoeba castellanii with various environmental samples from Algeria.

At the moment (as of August 2020) the genus " Cedratvirus " proposed by these authors is not yet registered in the database of the International Committee on Taxonomy of Viruses (ICTV) (Master Species List # 34 2018b), also at the National Center for Biotechnology Information ( NCBI) the term " Cedratvirus " is not used as a separate genus, but only as part of the name of a number of virus species of the family Pithoviridae ; however, Claire Bertelli and colleagues also speak in 2017 of a " Cedratvirus lineage " as a family group.

description

The virions (virus particles) of " Cedratvirus " reach a length of 1 to 1.2  µm and a diameter of up to 0.5 µm. The shape of the virions is egg-shaped and similar to the virions of the Pithovirus sibericum , they also have a two-layer envelope. The thickness of the virion envelopes varies at different stages of the infection cycle. In the early stages of infection, the outer layer has a thickness of 40 ± 5  nm and later grows to 55 ± 5 nm. Such changes can be caused by the storage of virus particles in phagosomes and vacuoles of the amoeba as well as by the gradual destruction of virions after the Release of viral DNA into the cytoplasm of the cell can be caused. As with Pithovirus sibericum , the DNA enters the cytoplasm through a special opening in the capsid of the virions.

The genome of “ Cedratvirus ” is a double-stranded circular DNA molecule with a length of 589,068  bp . The GC share of the genome is 42.6%. Despite the morphological similarity of the virions with those of “ Pithovirus ”, the genome of “ Cedratvirus A11 ” is 20,965 bp or approx. 97,000 bp shorter than that of “ Pithovirus sibericum ” or Pithovirus massiliensis . No palindromic sequences were found in the Cedratvirus genome , but 27 possible repeat regions were found. In the genome of Cedratvirus 574 proteins are probably encoded , more than that in the genus Pithovirus (425 in P. sibericum ). No tRNA genes were found in the genome . No homologues could be found in the databases for 177 of the Cedratvirus proteins ; 258 of the proteins are homologous to proteins from other viruses, 108 to proteins from eukaryotes and only 31 to proteins from prokaryotes . 84.1% of the viral proteins are homologous to the pithovirus . Protein homologues of eukaryotic origin exist to the green alga Micromonas pusilla ( Mamiellophyceae ), the amoeba host A. castellanii and the brown alga Ectocarpus siliculosus .

Many of the coding genes of " Cedratvirus " are involved in processes that are specific for giant viruses: For example, the genes for the synthesis of aromatic amino acids and the gene for D-3 phosphoglycerate dehydrogenase were found. Two copies of the ribonuclease III gene and a removed homolog of the ribonuclease H gene were also detected.

Propagation cycle

The infection cycle of " Cedratvirus " begins as usual for giant viruses: Virions are absorbed ( phagocytosed ) by amoeba and penetrate the phagosomes and vacuoles. After the internal virus membrane and the vacuole membrane have grown together, viral DNA enters the cytoplasm. Apparently only one layer of the bilayer capsid is involved in the output of the DNA. A number of empty virus particles that do not contain any DNA can be detected in the cytoplasm. Four hours after the infection appears a virus factory ( English virus factory ) in the cytoplasm of the cell. After two to four hours, mature virions can be detected there, whereby the formation of new particles continues. Ten hours after infection of the culture, some cells decompose and release virus particles, and 24 hours after infection, complete lysis of the culture occurs.

"Assumed system"

It is assumed that the closest relatives of the " Cedratvirus A11 " known to date are the " Pithovirus " representatives " P. sibericum " and " P. massiliensis ", which is why both genera were provisionally assigned to the family of " Pithoviridae ", an unconfirmed one (ie not yet officially recognized by the International Committee on Taxonomy of Viruses - ICTV) Group of giant viruses within the phylum Nucleocytoviricota (outdated Nucleocytoplasmic large DNA viruses , NCLDV). In 2017, the discovery of another species of " Cedratvirus " was announced - " Cedratvirus lausannensis ", which is also related to " Pithovirus ". It was found in a sample of water used to irrigate plants in France. In 2018 another representative of the genus was described - " Cedratvirus getuliensis ", which was discovered in Brazil. The phylogenetic analysis of 2018 showed that the Brazilian virus forms its own evolutionary branch in the genus Cedratvirus. Supplemented by further suggestions made in the meantime, the following assumed system of the extended family " Pithoviridae " results :

  • Family " Pithoviridae "
  • Genus " Pithovirus "
  • Genus " Cedratvirus "
  • Species " Brazilian cedratvirus IHUMI " (genome length 460,038 bp)
  • Species " Cedratvirus A11 " (genome length 589,068 bp) (type)
  • Species " Cedratvirus getuliensis "
  • Species " Cedratvirus lausannensis "
  • Species " Cedratvirus Zaza IHUMI "
  • Species " Cedratvirus kamchatka "
  • Family " Orpheoviridae " (according to some authors a synonym for " Pithoviridae ")
  • Species " Orpheovirus IHUMI-LCC2 "
  • without family assignment:

Individual evidence

  1. ↑ a b c d e ICTV: ICTV Master Species List 2019.v1 , New MSL including all taxa updates since the 2018b release, March 2020 (MSL # 35)
  2. ↑ a b c d e Julien Andreani, Jacques Y. B. Khalil, Emeline Baptiste, Issam Hasni, Caroline Michelle, Didier Raoult, Anthony Levasseur, Bernard La Scola: Orpheovirus IHUMI-LCC2: A New Virus among the Giant Viruses . In: Frontiers in Microbiology . tape 8 , January 22, 2018, ISSN  1664-302X , doi : 10.3389 / fmicb.2017.02643 ( frontiersin.org [PDF]). Quote: “… we recently described a new virus Cedratvirus A11 (Andreani et al., 2016) a possible new genus in the putative Pithoviridae family”
  3. ↑ a b c d e f Andreani J., Aherfi S., Bou Khalil J. Y., Di Pinto F., Bitam I., Raoult D., Colson P., La Scola B .: Cedratvirus, a Double-Cork Structured Giant Virus , is a Distant Relative of Pithoviruses . In: Viruses, November 3, 2016; 8 (11). pii: E300. doi: 10.3390 / v8110300 , PMID 27827884
  4. ↑ a b c Julien Andreani, Jonathan Verneau, Didier Raoult, Anthony Levasseurn Bernard La Scola: Deciphering viral presences: two novel partial giant viruses detected in marine metagenome and in a mine drainage metagenome , in: Virology Journal, Volume 15, No. 66 , April 10, 2018, doi: 10.1186 / s12985-018-0976-9
  5. ↑ Search Cedratvirus database in ICTV . Archived from the original on October 4, 2013. Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved July 6, 2019. @1@ 2Template: Webachiv / IABot / www.ictvonline.org
  6. ↑ Claire Bertelli, Linda Mueller, Vincent Thomas, Trestan Pillonel, Nicolas Jacquier, Gilbert Greub: Cedratvirus lausannensis - digging into Pithoviridae diversity , in: Environmental Microbiology 19 (10), pp. 4022-4034, June 15, 2017, doi: 10.1111 /1462-2920.13813 . Fig. 4 and following text
  7. ↑ a b c Disa Bäckström, Natalya Yutin, Steffen L. Jørgensen, Jennah Dharamshi, Felix Homa, Katarzyna Zaremba-Niedwiedzka, Anja Spang, Yuri I. Wolf, Eugene V. Koonin, Thijs JG Ettema; Richard P. Novick (Ed.): Virus Genomes from Deep Sea Sediments Expand the Ocean Megavirome and Support Independent Origins of Viral Gigantism , in: mBio Vol. 10, No. 2, March – April 2019, pp. E02497-18, PDF , doi: 10.1128 / mBio.02497-18 , PMC 6401483 (free full text), PMID 30837339 , ResearchGate
  8. ^ Bertelli C., Mueller L., Thomas V., Pillonel T., Jacquier N., Greub G .: Cedratvirus lausannensis - digging into Pithoviridae diversity , in: Environmental Microbiology 19 (10), October 2017, pp. 4022-4034 , Epub August 14, 2017, doi: 10.1111 / 1462-2920.13813 , PMID 28618143
  9. ↑ Silva LKDS, Andrade ACDSP, Dornas F. P., Rodrigues RAL, Arantes T., Kroon E. G., Bonjardim C. A., Abrahão J. S .: Cedratvirus getuliensis replication cycle: an in-depth morphological analysis , in: Scientific Reports, March 5, 2018, p. 4000, doi: 10.1038 / s41598-018-22398-3 , PMID 29507337
  10. ↑ Rodrigues RAL, Andreani J., Andrade ACDSP, Machado T. B., Abdi S., Levasseur A., ​​Abrahão J. S., La Scola B .: Morphologic and Genomic Analyzes of New Isolates Reveal a Second Lineage of Cedratviruses . In: Journal Of Virology 92 (13), June 13, 2018, pii: e00372-18, print July 1, 2018, doi: 10.1128 / JVI.00372-18 , PMID 29695424
  11. ↑ a b NCBI: Cedratvirus (as token [set )]
  12. ↑ a b Clara Rolland, Julien Andreani, Amina Cherif Louazani, Sarah Aherfi, Rania Francis, Rodrigo Rodrigues, Ludmila Santos Silva, Dehia Sahmi, Said Mougari, Nisrine Chelkha, Meriem Bekliz, Lorena Silva, Felipe Assis, Fábio Dornas, Jacques Yaacoub Bou Khalil, Isabelle Pagnier, Christelle Desnues, Anthony Levasseur, Philippe Colson, Jônatas Abrahão, Bernard La Scola: Discovery and Further Studies on Giant Viruses at the IHU Mediterranee Infection That Modified the Perception of the Virosphere , in: Viruses 11 (4), March / April 2019, pii: E312, doi: 10.3390 / v11040312 , PMC 6520786 (free full text), PMID 30935049
  13. ↑ NCBI: Orpheovirus IHUMI-LCC2 (species)
  14. ↑ a b Frederik Schulz, Lauren Alteio, Danielle Goudeau, Elizabeth M. Ryan, Feiqiao B. Yu, Rex R. Malmstrom, Jeffrey Blanchard, Tanja Woyke: Hidden diversity of soil giant viruses . In: Nature Communications . tape 9 , no. 1 , 2018, ISSN  2041-1723 , Article 4881, Note 38 , doi : 10.1038 / s41467-018-07335-2 ( nature.com ).

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