London, March 18 : Modern Microbialites - organosedimentary structures built by the interaction of organisms and their environment - may be endemic remnants of ancient ecosystems, according to a team of researchers from the US and Singapore.
The research team says that their suggestion is based on an analysis of the geographical distribution of viral communities in microbialites, which first appeared in the geological record 3.5 billion years ago and have been the main evidence of life on Earth for more than two billion years.
The findings, reported in two separate papers, indicate that viruses associated with such structures are very different not only from each other but also from those found in any other ecosystem so far.
"Using DNA sequencing technology, we were able to identify unknown viruses in various environments relevant to human health. This collaboration is the first ever large-scale effort to analyse biodiversity and biogeography of viruses in the environments around humans," Nature magazine quoted Dr. Ruan Yijun, Senior Group Leader at the Genome Institute of Singapore (GIS), as saying.
"We have been interested in this kind of analysis since the SARS (severe acute respiratory syndrome) outbreak in 2002. In pursuit of this interest, we established a virus discovery programme at GIS, resulting in the discovery of abundant viruses in the human gut (PLoS Biology, 2006) and different variants of dengue viruses. Now, with more viral metagenomic data accumulated, we are able to summarise the biodiversity and biogeography on a global scale," added Dr. Ruan.
The two papers describing the research can be found in Nature magazine under the titles 'Biodiversity and biogeography of phages in modern stromatolites and thrombolites' and 'Functional metagenomic profiling of nine biomes'.