Featured Research

from universities, journals, and other organizations

Mimivirus isolated, genome amputated

Date:
June 19, 2011
Source:
CNRS (Délégation Paris Michel-Ange)
Summary:
In the absence of competition with other microorganisms, Mimivirus, the largest known DNA virus, loses 17% of its genome.

In the absence of competition with other microorganisms, Mimivirus, the largest known DNA virus, loses 17% of its genome. This has recently been demonstrated by a French-American collaboration including researchers from CNRS, the Université de la Méditerranée and the Université de Provence[1]. The results are published online this week in the journal Proceedings of the National Academy of Sciences.

With 900 genes of their own, Mimiviruses, discovered in 2003 by two teams headed by Professor Didier Raoult, represent the largest known group of DNA viruses. They have been discovered in amoebas, unicellular beings that can be found in the water-cooling circuits of air conditioning systems. The originality of this virus stems from its size and its vulnerability to infection by small viruses: virophages.

In a natural environment, in other words within amoebas, Mimiviruses live in a "community." They share their amoebic space with other organisms such as viruses and bacteria. Constant exchanges of genes within these organisms with intra-amoebal life, not just between each other but also with their protozoan host, have allowed this evolution towards a "community" life.

The researchers cultivated the Mimivirus in the laboratory, alone in an amoeba and without contact with other organisms. Through accelerated evolution (only 150 passages[2]), they observed a 17% reduction in the size of its genome. This genomic loss mainly occurs in the form of deletions[3] of both ends of its genome. In the absence of other microorganisms and thus competition within the amoeba, the Mimivirus then eliminates part of its genome by deleting in particular the genes involved in the formation of the long fibers that surround its capsid[4]. The Mimivirus therefore becomes "bald." The researchers also observed that it becomes resistant to virophages.

This work shows that a change of ecosystem may be associated with a major and rapid modification of the genome of microorganisms.


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. M. Boyer, S. Azza, L. Barrassi, T. Klose, A. Campocasso, I. Pagnier, G. Fournous, A. Borg, C. Robert, X. Zhang, C. Desnues, B. Henrissat, M. G. Rossmann, B. La Scola, D. Raoult. Mimivirus shows dramatic genome reduction after intraamoebal culture. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1101118108

Cite This Page:

CNRS (Délégation Paris Michel-Ange). "Mimivirus isolated, genome amputated." ScienceDaily. ScienceDaily, 19 June 2011. <www.sciencedaily.com/releases/2011/06/110614083936.htm>.
CNRS (Délégation Paris Michel-Ange). (2011, June 19). Mimivirus isolated, genome amputated. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2011/06/110614083936.htm
CNRS (Délégation Paris Michel-Ange). "Mimivirus isolated, genome amputated." ScienceDaily. www.sciencedaily.com/releases/2011/06/110614083936.htm (accessed August 20, 2014).

Share This




More Plants & Animals News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Newsy (Aug. 19, 2014) — Scientists have developed a new device that mimics the way octopuses blend in with their surroundings to hide from dangerous predators. Video provided by Newsy
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
USDA Cracks Down On Imports From Foreign Puppy Mills

USDA Cracks Down On Imports From Foreign Puppy Mills

Newsy (Aug. 18, 2014) — New USDA measures to regulate dog imports aim to crack down on buying dogs from overseas puppy mills. Video provided by Newsy
Powered by NewsLook.com
Bone Marrow Drug Regrows Hair In Some Alopecia Patients

Bone Marrow Drug Regrows Hair In Some Alopecia Patients

Newsy (Aug. 18, 2014) — Researchers performed an experiment using an FDA-approved drug known as ruxolitinib. They found it to be successful in the majority of patients. Video provided by Newsy
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