CHIRI and Murdoch University researchers have shed new light on the private life of bacteria, following a discovery that holds clues to the way bacteria adapt to new environments.
Research leader Dr Josh Ramsay, who was recently awarded ‘Best Paper by a CHIRI Early Career Researcher’ by WA Deputy Premier and Minister for Health and for Mental Health, the Honorable Roger Cook MLA, has helped uncover a new type of gene transfer within bacteria that had never before been observed or expected. “It happened when my team noticed bacterial genomes were being rearranged and flipped in strange ways, and we thought we’d investigate this further,” Josh said.
“This process is associated with a phenomenon called horizontal gene transfer, where the transfer of a single mobile genetic element of DNA ‘jumps’ from one bacterium to another, rather than from parent to offspring as we know it in humans,” he said.
“However, in this case, rather than just a single mobile genetic element going from one bacterium to another, we noticed the genetic element was present in three separate parts of the chromosome. It would then assemble by cutting its three parts out of the chromosome and forming a single circular piece of DNA, and then disassemble into three different parts into its new host.”
Josh said this finding was extremely important as it adds to our understanding of genetic mobile elements and their role in bacterial evolution and adaptation to new situations and environments.
“Before this work it was never expected that a genetic mobile element could exist in such a complex state, and as such we suspect similar complex mobile elements to exist in many other kinds of bacteria,” he said.
“These mobile genetic elements are present in nearly all bacteria examined and act like transport systems for spreading new genes between organisms, so the more we know about them, the better we are able to understand how bacteria become toxic or resistant to antibiotics, for example.”
Josh said his team will continue to dissect the process on how these mobile genetic elements transfer, as well as try and understand why they exist at all.
He said the fact these elements exist in the first place and how they weren’t expected exposed how little was known about the private lives of bacteria and how they evolve.
“We are increasingly realising just how important bacteria are in every aspect of our lives – from health and disease to food and the environment – so the more we understand about their evolutionary motivations the better,” he said.
The paper, Assembly and transfer of tripartite integrative and conjugative genetic elements, can be viewed at: https://www.ncbi.nlm.nih.gov/pubmed/27733511
