We recently posted an update on horizontal gene transfer (HGT) to highlight the existence of strategies used by bacteria to exchange DNA – in addition to those traditionally acknowledged, that is transformation, transduction and conjugation. One of these more recently recognized mechanisms involves entities called gene transfer agents (GTAs).
by Mechas and Roberto
We recently prepared a lecture that included a brief discussion of bacterial evolution. Of course, we covered horizontal gene transfer (HGT), which we consider a key pillar in the evolutionary process. We dutifully began our presentation by listing, perforce: transformation, conjugation, and transduction.
For a very long time, symbiogenesis was scoffed at as a fringe science. This mindset plagued the field from the get-go in the 1880s, when the botanist Andreas Franz Wilhem Schimper first put forth the idea that eukaryotic organelles might be bacterial, to the turn of the century, which saw the first key paper on symbiogenesis...
Microbial genotoxic compounds – molecules that damage DNA – are found aplenty in nature. Doxorubicin and bleomycin come to mind; powerful DNA damaging agents developed as anti-cancer therapeutics but whose extreme toxicity is part of what makes some cancer chemotherapies arduous and risky.
When it comes to generating variability in genes and functions, microbes are at the top of the list. Much of their genome plasticity and capacity to adapt to changing environments is driven by horizontal gene transfer (HGT), the acquisition of genetic information from other cells rather than from vertical inheritance upon division.
Yersinia pestis. How immediate our reaction can be to the species name of this bacterium, making us conjure up images of pestilence. As its discoverer, Alexander Yersin, wrote in 1894 of an outbreak of bubonic plague in Hong Kong, this is the "bacille de la peste." (Working independently, Kitasato Shibasaburo also characterized the plague bacterium at nearly the exact same time.)