RNA World Gets a Boost: New Study Shows RNA Can Form Complex Filaments and Icosahedral Cages

RNA world: unexpected structural diversity

Scientists have long assumed that the RNA world could only generate modest hairpins and simple loops. A pre‑print released on July 1 overturns that view, showing that naturally occurring RNA strands can self‑assemble into filamentous ropes and virus‑sized icosahedral cages. The discovery, led by Lin Huang of Sun Yat‑Sen University, began with a search for “kissing‑stem‑loop” motifs in bacteriophage genomes. After isolating several candidates, the team let the RNAs mingle in vitro and captured the resulting architectures with cryo‑electron microscopy.

“We show RNA can do things which we have never seen before,” Huang told Live Science.

The filaments resemble cellular scaffolds that guide shape and movement, while the cages rival protein capsids that encase viral genomes. Each construct was built from short RNAs no longer than ↑ 200 nucleotides, suggesting that even fragmented strands could have formed larger machines in primordial soups.

Critics, such as evolutionary biologist Anna Medvegy of Eötvös Loránd University, ask whether the harsh conditions of early Earth—high temperature, low pH—would permit such assemblies. Replicating those parameters in the lab would lend weight to the hypothesis that RNA‑based capsids once packaged genetic material.

Beyond origins‑of‑life theory, the cages may inspire Reuters-covered nanotech ventures that seek RNA‑based delivery vehicles, echoing the Bloomberg push toward RNA therapeutics. The work also dovetails with recent discussions on the pandemic and the surge in RNA vaccine platforms.