Biologists at Stanford University have reported the discovery of a novel type of virus-like entity, referred to as "obelisks," inhabiting bacteria in the human mouth and gut. These entities possess genomes composed of loops of RNA, and their sequences have been identified in various locations worldwide.
Obelisks appear to have genomes made up of circular RNA sequences and are distinct from typical viruses. While the impact of obelisks on human health remains uncertain, they could potentially influence the genetic activity of their bacterial hosts, thereby affecting human genes.
The researchers used sophisticated software to analyze existing gene catalogs from microbes living in humans to identify RNA sequences predicted to form circular structures, similar to the genetic material found in viruses and viroids. The study identified nearly 30,000 predicted RNA circles, each representing a potential obelisk. Obelisks were found in 7% of human gut bacteria and half of the bacteria in the human mouth, with distinctive sequences observed in microbes from different body parts.
The findings highlight the complexity of the microbial world within the human body and raise questions about the evolution of viruses and related entities. The discovery adds to the growing understanding of the diversity of viral structures and their potential interactions within microbiomes.
The researchers note that further investigation is required to determine the distinct characteristics of obelisks compared to other viral entities and viroids, emphasizing the ongoing exploration of the viral universe and its evolution on Earth.
More: https://www.science.org/content/article/it-s-insane-new-viruslike-entities-found-human-gut-microbes
