Featured Research

from universities, journals, and other organizations

Marseillevirus -- a new member of the giant viruses

Date:
December 31, 2009
Source:
CNRS (Délégation Paris Michel-Ange)
Summary:
After Mimivirus, Mamavirus and the virophage, the group of giant viruses now has a new member called Marseillevirus. The new virus was discovered in an amoeba by a team of French researchers. Their findings suggest the exchange of genes in amoebae that may lead to the constitution of different gene repertoires that could be a source of new pathogens.

Marseillevirus at different stages of its formation in an amoeba.
Credit: Copyright Raoult / URMITE

After Mimivirus, Mamavirus and the virophage, the group of giant viruses now has a new member called Marseillevirus.

Discovered in an amoeba by the team led by Didier Raoult at the Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes research group (CNRS/Université Aix-Marseille 2), a description of this new virus was published online in the Proceedings of the National Academy of Sciences (PNAS). These findings suggest the exchange of genes in amoebae that may lead to the constitution of different gene repertoires that could be a source of new pathogens.

Amoebae are single-cell, eukaryote (possessing a nucleus) living organisms, some of which are human or animal parasites and may cause a variety of pathologies. Most amoebae live in water, damp soils or mosses. They are mobile and capable of ingesting a wide variety of different organisms (for example, viruses or bacteria with extraordinarily broadly ranging sizes and lifestyles). Thus amoebae provide a site for numerous exchanges of genetic material arising from the many organisms that "colonize" them.

The team led by Didier Raoult at URMITE (CNRS/Université Aix-Marseille 2)1 has recently discovered, in an amoeba, a member of a new family of giant viruses, which it has called the Marseillevirus, smaller than Mimivirus, which is the largest giant virus known at present.

With a chimeric genome (containing both DNA and RNA) of 368,000 base pairs, Marseillevirus is indeed the fifth largest viral genome to be sequenced. It has an icosahedral shape and a diameter of about 250 nanometers (or 250 millionths of a millimeter).

In addition, the researchers discovered that it contained genes from markedly differing sources, i.e. of bacterial, viral or eukaryote origin, or arising from Archae.2 The genome of Marseillevirus, a mosaic of genes from very different organisms, thus demonstrates the exchange of genes between the organisms that "colonize" amoebae.

These studies have also revealed the role of amoebae, and more generally phagocytic protists (or single-cell eukaryotes) that feed on microbes in the environment, in the constitution of new gene "repertoires" which may be capable of generating new agents that will be pathogenic to multicellular organisms such as animals, plants or humans.

Notes:

1. URMITE: Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (CNRS/Université Aix-Marseille 2)

2. The archaea are a major group of single-cell microorganisms which, like bacteria, have neither a nucleus nor intracellular organelles.


Story Source:

The above story is based on materials provided by CNRS (Délégation Paris Michel-Ange). Note: Materials may be edited for content and length.


Journal Reference:

  1. Boyer M., Raoult D. et al. Giant Marseillevirus highlights the role of amoebae as a melting pot in emergence of chimeric microorganisms. Proceedings of the National Academy of Sciences, 2009; 106 (51): 21848 DOI: 10.1073/pnas.0911354106

Cite This Page:

CNRS (Délégation Paris Michel-Ange). "Marseillevirus -- a new member of the giant viruses." ScienceDaily. ScienceDaily, 31 December 2009. <www.sciencedaily.com/releases/2009/12/091230113210.htm>.
CNRS (Délégation Paris Michel-Ange). (2009, December 31). Marseillevirus -- a new member of the giant viruses. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2009/12/091230113210.htm
CNRS (Délégation Paris Michel-Ange). "Marseillevirus -- a new member of the giant viruses." ScienceDaily. www.sciencedaily.com/releases/2009/12/091230113210.htm (accessed July 29, 2014).

Share This




More Plants & Animals News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) — West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) — Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) — The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) — A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins