Circular intron RNA identified as possible vehicle for cross-species transfer of jumping genes

Researchers have identified what may be a new mechanism by which transposable elements — sequences sometimes called 'jumping genes' — can spread between distantly related species. Publishing work covered by ScienceDaily, the team found circular RNA derived from Group I self-splicing introns inside a predatory bacterium, apparently acquired from the dead cells of another microorganism it had engulfed.

The significance of the finding lies in the physical properties of the RNA: circular RNA molecules lack free ends, making them substantially more resistant to enzymatic degradation than their linear counterparts. This stability could allow them to persist long enough after cellular lysis to be taken up by another organism — a route that would operate independently of the viral or plasmid vectors previously assumed to be the dominant vehicles for horizontal gene transfer of mobile elements.

The work contributes to the field of mobile genetic element biology and horizontal gene transfer, areas with implications for understanding genome evolution, the spread of antimicrobial resistance elements, and the deep evolutionary history of genome composition across the tree of life. The source article does not name the journal of publication, so readers should seek the primary literature via the ScienceDaily link for full methodological detail.

For educators and students, the study offers a concrete illustration of how genomes are not static entities and how non-coding RNA can serve structural as well as regulatory functions.