Bacterial DNA Inversions: A Genetic Flip That Rewrites the Rules

Stanford Medicine researchers are challenging the long-held belief that one gene codes for only one protein. According to a study they published recently in Nature, some prokaryotes can undergo DNA inversions within a single gene, effectively recoding their genetic identity.

These inversions, akin to a genetic cartwheel, can dramatically alter an organism's appearance or function. As Rachael Chanin, first author of the paper, explains "Bacteria are even cooler than I originally thought, and I'm a microbiologist, so I already thought they were pretty cool."

While scientists have known about DNA inversions in bacteria for decades, this is the first time they've been observed within a single gene. The implications are significant, as these inversions can activate or deactivate genes, or even code for entirely different proteins.

The discovery was made possible by an algorithm called PhaVa, developed by Patrick West. This software scans prokaryotic genomes for "flippable" segments with inverted repeats, creating a catalog of potential inversions. The algorithm identified thousands of inversions across various prokaryotic species, suggesting that this phenomenon may be relatively common.

Ami Bhatt, senior author of the study, initially found the results hard to believe. "I remember seeing the data, and I thought, 'No way, this can't be right, because it's too crazy to be true,'" she said. However, years of rigorous verification have confirmed their findings.

The research team is now focused on understanding what triggers these inversions and which enzymes mediate the process. Bhatt sees potential applications in synthetic biology and disease regulation, suggesting that scientists might eventually be able to create toggleable bacterial systems to control gene expression.

This discovery opens up new avenues for research and potential applications in biotechnology and medicine. As Chanin puts it, "This type of adaptation has just been hiding in front of us, waiting for the right tool and the right technology and biological question to be asked."