In March 2004, an international team of scientists reported that viroids, small infectious particles of naked RNA, may be employing RNA-silencing machinery to work their damage.1 Several weeks later, ...

The surprising discovery of entities smaller than viruses raises profound questions about what life is and how it got started ...

Viral genomes are differentiated from other replicons and genetic material, such as viroids or plasmids, through a unique three-part strategy for survival that is common to all viruses.

Their unique characteristics place them between viruses and tiny viroids, without being either type of infectious agent. These RNA circles are highly self-complementary, allowing them to adopt a ...

Far smaller than any known virus, it more closely resembles subviral agents known as viroids and virusoids. These are characterized by their circular genomes and lack of replication proteins ...

Obelisks are not easily categorized. They are not viruses, bacteria, or classic viroids, yet they share traits with all three. This ambiguity challenges existing frameworks for classifying life ...

Obelisks defy categorization—lacking the protein shells of viruses yet resembling viroids, these RNA loops represent a distinct and enigmatic form of life. Obelisks could represent ancient ...