Bacteria have to deal with sometimes wildly varying conditions. They have a bag of tricks to survive and thrive, even though they have far fewer genes than, say, we humans to cobble together many changes in function. Well, that’s not quite accurate. Let’s look at findings by Rachael Chanin and colleagues from Stanford and Princeton, which built on almost 50 years of studies by other scientists.
Bacteria, it turns out, can chop out genes in their circular genome, flip them end-for-end, and reinsert them. Just like a word flipped end-for-end the gene reads entirely differently, making different proteins or other factors. In essence, bacteria have spare genes. They turn these inverted genes on and off, adapting to new conditions, as other research has shown.
Chanin and her colleagues developed a technological tour de force to identify the flippable regions in the genome by the patterns of base pairs. They looked at genetic sequences from 29,989 samples from 4,115 species of bacteria, finding 4,622 “invertrons.” Among the takeaway lessons is that a spiffy genetic sequence from a bacterium is a snapshot, in which the current order of genes is one of many possibilities. Such simple organisms have striking sophistication, especially when we add in their diverse antiviral defenses. They’ve had billions of years to make great systems!
This has been an outreach activity of the Las Cruces Academy, viewable at GreatSchools.org.
Source: Nature, 3 Oct. 2024, pp. 234 ff.
