New giant virus discovered

Scientists have discovered a new family of giant viruses -- created within amoebae, they linkurl:report;http://www.pnas.org/cgi/doi/10.1073/pnas.0911354106 in this week's issue of the Proceedings of the National Academy of Sciences. Structural analysis of giant virus Image: Xiao C, Kuznetsov YG, Sun S, Hafenstein SL, Kostyuchenko VA, et al. (2009) The new virus type is uniquely comprised of genes from a variety of origins, including bacteria, eukaryotes and viruses. Amoebae are not an uncomm

Written byKatherine Bagley

| 2 min read

Save for Later

Structural analysis of giant virus
Image: Xiao C, Kuznetsov YG, Sun S, Hafenstein
SL, Kostyuchenko VA, et al. (2009)

The new virus type is uniquely comprised of genes from a variety of origins, including bacteria, eukaryotes and viruses. Amoebae are not an uncommon source of viruses, since their insides are melting pots of viruses and other organisms, allowing viruses to grow into so-called "giants" by adopting genes from other organisms within the amoebae. "Researchers have recognized the potential of amoebae as a source of new viruses for a while," said linkurl:Patrick Forterre,;http://www.pasteur.fr/ip/easysite/go/03b-00002i-01l/recherche/departements-scientifiques/microbiologie/unites-et-groupes/unite-de-biologie-moleculaire-du-gene-chez-les-extremophiles/les-membres-de-l-equipe/patrick-forterre a microbiologist at the Pasteur Institute in Paris, France, who was not involved with the study. "But [this paper] is the first real confirmation that [other giant viruses found in amoebae are] not an exception... It also means there might be a huge number of diverse giant viruses in amoebae that haven't been discovered yet." Giant viruses were first discovered in the late 1990s, and are characterized by their large particle sizes, typically bigger than 200 nanometers, and genetic complexity. (Medium-sized viruses such as adenovirus and HIV measure closer to 100-200 nm.) This newest giant virus was discovered by linkurl:Didier Raoult;http://www.antimicrobe.org/authors/didier_raoult.asp and colleagues the Universite de la Mediterranee in Marseille, France. The scientists isolated the new virus, named Marseillevirus, from Acanthamoeba polyphaga. Phylogenetic analysis of the Marseillevirus revealed several genetic similarities to other giant viruses. It also carries genes obtained from eukaryotic hosts and their parasites or symbionts. "Other viruses are commonly alone in their host cell," says Raoult. But because amoebae feed on relatively large particles, over 500nm, they are one of the few organisms that can take in and host a giant virus. And since amoebae are not picky eaters, they typically contain a mixture of organisms. The giant virus adopts genes from the other organisms, including eukaryotes, bacteria and other viruses, that improve function. In the case of the Marseillevirus, genes with defense or repair functions are thought to have come from bacteria; those with metabolic functions likely have eukaryotic and bacteria origins; and those for signal transduction probably stem from eukaryotes, the scientists report. The team's findings led them to conclude that amoebae are "melting pots" for viruses, said Raoult, enabling viruses to create complex gene repertoires with varied genetic origins. It is unclear whether this new giant virus is pathogenic, but may turn out to be so, said Raoult, because of the virus's "repertoire of genes and the capability to resist intracellular killing."
**__Related stories:__***linkurl:A virus's virus;http://www.the-scientist.com/blog/display/54915/
[6th August 2008]

New giant virus discovered

The Scientist ARCHIVES

Become a Member of

Meet the Author

Katherine Bagley

Related Research Resources

What Is the Amniotic Fluid Composed of?

Research Resources

Podcasts

Webinars

Videos

Infographics

eBooks

Advancing Drug Discovery with Complex Human In Vitro Models

Redefining Immunology Through Advanced Technologies

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Maximizing Cancer Research Model Systems

Products

Product News

Sino Biological Pioneers Life Sciences Innovation with High-Quality Bioreagents on Inside Business Today with Bill and Guiliana Rancic

Sino Biological Expands Research Reagent Portfolio to Support Global Nipah Virus Vaccine and Diagnostic Development

Beckman Coulter Life Sciences Partners with Automata to Accelerate AI-Ready Laboratory Automation

Refeyn named in the Sunday Times 100 Tech list of the UK’s fastest-growing technology companies