Self‑replicating circular RNA persists in extreme environments: Insights from hot spring microbiomes

Although the genetic material of most living organisms is DNA, various self-replicating agents rely instead on RNA, including RNA viruses and viroids, which are infectious RNA molecules that are smaller and structurally simpler than RNA viruses. These RNA-based replicators are considered important for understanding the origin and early evolution of life. However, the distribution, diversity, and ecological range of self-replicating RNAs across different environments remain poorly understood.