Antarctic lake home to diverse community of viruses

Nov 11, 2009 by Lin Edwards weblog
Antarctic lake
Antarctic lake. Image credit: British Antarctica Survey.

(PhysOrg.com) -- A study of the genetic structure of viruses in an Antarctic lake has revealed an astonishing genetic richness in the large number of viral families discovered.

Aquatic viruses usually infect prokaryotes such as bacteria, but the viruses in the Antarctic had a large proportion of viruses that infect eukaryotes. The findings included small single stranded DNA (ssDNA) viruses and phycodnaviruses that have never previously been seen in aquatic environments.

The researchers, Alberto Lopez-Bueno and colleagues, from Spain and the UK, examined samples taken from Lake Limnopolar on Livingston Island in the Antarctic before and during the summer, and found the to be rich in microorganisms and a diverse collection of viruses that prey on them. The number of viral genotypes found was unusually high, running into thousands instead of the more usual hundreds, and less than 3 percent of the genome sequences were similar to previously identified viral genomes from aquatic systems. Many of the ssDNA viruses were related to non-aquatic viruses that infect plants, mammals and birds, and some had never been found in aquatic environments before.

The scientists also observed a change in the assemblage with the seasons. When the lake was covered in ice during spring, the smaller single strand DNA viruses dominated, while in summer, when the lake was open, the larger (>50 nanometer) double-stranded DNA viruses dominated, possibly because of seasonal differences in the host organisms, such as the algal blooms that appear in summer.

The scientists also found the double-stranded viruses helped the bacteria survive by assisting their metabolism of amino acids and carbohydrates, and helping with respiration.

Antarctic lakes are covered with ice for around nine months of the year, and the underwater environment is cold, dark, and contains few nutrients, and is home to bacteria, , algae and viruses, and little else. In these conditions viruses probably play an important part in controlling the other microbes.

Viruses from Antarctica have been difficult to study in the past because they cannot be grown in the laboratory, but new genome sequencing technologies are allowing researchers to identify viruses without the need to grow them.

The research paper is published in the November issue of Science.

More information: High Diversity of the Viral Community from an , Science 6 November 2009: Vol. 326. no. 5954, pp. 858 - 861; DOI: 10.1126/science.1179287

© 2009 PhysOrg.com

Explore further: How plant cell compartments change with cell growth

add to favorites email to friend print save as pdf

Related Stories

Research ties harmless viruses to cancer

Feb 22, 2007

Research led by Cold Spring Harbor Laboratory (CSHL) may link viruses that have been considered harmless to chromosomal instability (CIN) and cancer. "If the model that we propose is correct, protecting the body against viruses, ...

Bees may transmit viruses to offspring

Jan 19, 2006

Researchers from the U.S. Department of Agriculture report what may be the first evidence of queen honeybees transmitting viruses to their offspring.

Recommended for you

How plant cell compartments change with cell growth

Aug 22, 2014

A research team led by Kiminori Toyooka from the RIKEN Center for Sustainable Resource Science has developed a sophisticated microscopy technique that for the first time captures the detailed movement of ...

Plants can 'switch off' virus DNA

Aug 22, 2014

A team of virologists and plant geneticists at Wageningen UR has demonstrated that when tomato plants contain Ty-1 resistance to the important Tomato yellow leaf curl virus (TYLCV), parts of the virus DNA ...

A better understanding of cell to cell communication

Aug 22, 2014

Researchers of the ISREC Institute at the School of Life Sciences, EPFL, have deciphered the mechanism whereby some microRNAs are retained in the cell while others are secreted and delivered to neighboring ...

A glimpse at the rings that make cell division possible

Aug 22, 2014

Forming like a blown smoke ring does, a "contractile ring" similar to a tiny muscle pinches yeast cells in two. The division of cells makes life possible, but the actual mechanics of this fundamental process ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Mercury_01
not rated yet Nov 12, 2009
So... are these the viruses that made so many scientists sick a few years ago? The 7 or 8 of them that had to be flown out under harsh (and unusual)winter conditions?