A new "tree of life" has been constructed by researchers at the Virginia Bioinformatics Institute (VBI) at Virginia Tech for the gamma-proteobacteria, a large group of medically and scientifically important bacteria that includes Escherichia coli, Salmonella typhimurium, and other disease-causing organisms.* By building powerful phylogenetic trees, scientists are able to quickly identify similarities and differences between the make-up of many different organisms, crucial information in the search for treatments to fight anything from the bugs that cause food poisoning to the pathogens that cause life-threatening diseases such as cholera and the plague.
A "tree of life," or phylogenetic tree, is a way to visualize the evolutionary relationships among different biological species that have descended from a common ancestor. The gamma-proteobacteria tree developed by VBI researchers was reconstructed using powerful computers from as many as 30 million data points of bacterial sequence information.
Kelly Williams, Research Investigator at VBI, remarked: "Ribosomal RNA is one of the central components of the ribosome, the protein manufacturing machinery of all living cells. In the past, researchers have often depended on looking at a single ribosomal RNA gene to construct evolutionary relationships for their tree-building efforts. The method we use to make our tree of life uses hundreds of different genes and integrates much more information than can be gleaned from the traditional single gene approach. We firmly believe that the multi-gene or phylogenomics approach should become the standard for tree-building when several genome sequences are available, which is now the case for most bacterial groups."
The researchers selected 108 available genomes from the more than 200 complete and partial sequences available for the gamma-proteobacteria, placing the emphasis on the diversity of the bacterial species and quality of the original seque
|Contact: Barry Whyte|