14 DAY TRIAL // In a finding that could significantly accelerate the rate at which correlations are found between bacterial species, researchers at the Virginia Institute of Technology (Virginia Tech) Bioinformatics Institute (VBI) managed to devise a new “tree of life” for gamma-proteobacteria. This particular class of bacteria is very significant for medicine, bioengineering and science, as it includes such members as the common Escherichia coli, Salmonella typhimurium and Vibrio cholerae (the agent that causes cholera).
With the development of the new phylogenetic tree, researchers now have a much better tool at their disposal for tracking down potential connections between various bacteria species, as well as for producing new types of drugs to fight the diseases these microorganisms cause. The VBI science team explains that developing a phylogenetic tree basically means constructing a means of visualizing the evolutionary relationships that exist between different biological species, in this case, bacteria. This helps researchers track down how various traits jumped species, or were passed down from one to the other. Knowing the origin of a pathogen's trait makes it easier to develop methods of fighting that trait.
“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,” explains VBI research investigator Kelly Williams, who was a part of the new study.
According to the team, more than 30 million data points of bacterial sequence information were introduced in computer models, in order to obtain the new phylogenetic tree for gamma-proteobacteria. “Some parts of our tree were still not fully resolved, but we believe that future work will improve our method further to handle these deficiencies,” Williams says. She adds that the VBI group used some 200 complete and partial sequences available for the gamma-proteobacteria to extract 108 available genomes. All of these data were then inserted into the computers for modeling.