Since the genetic code was first deciphered in the 1960s, our genes seemed like an open book. By reading and decoding our chromosomes as linear strings of letters, like sentences in a novel, we can identify the genes in our genome and learn why changes in a gene’s code affect health.

This linear rule of life was thought to govern all forms of life—from humans down to bacteria.

But a new study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11100668/) by Columbia researchers shows that bacteria break that rule and can create free-floating and ephemeral genes, raising the possibility that similar genes exist outside of our own genome.

“What this discovery upends is the notion that the chromosome has the complete set of instructions that cells use to produce proteins,” says Samuel Sternberg, associate professor of biochemistry & molecular biology at the Vagelos College of Physicians and Surgeons, who led the research with Stephen Tang, an MD/PhD student at the medical school.

“We now know that, at least in bacteria, there can be other instructions not preserved in the genome that are nonetheless essential for cell survival.”