If the reader does not believe that viroids and satellites are distinctive, then surely prions, infectious agents composed only of protein, must impress. The question of whether infectious agents exist without genomes arose with the discovery and characterization of infectious agents associated with a group of diseases called transmissible spongiform ...

On episode #321 of the science show This Week in Virology, Paul Duprex joins the TWiV team to discuss the current moratorium on viral research to alter transmission, range and resistance, infectivity and immunity, and pathogenesis. You can find TWiV #321 at www.microbe.tv/twiv.

Satellites are subviral agents that differ from viroids because they depend on the presence of a helper virus for their propagation. Satellite viruses are particles that contain nucleic acid genomes encoding a structural protein that encapsidates the satellite genome. Satellite RNAs do not encode capsid protein, but are packaged by a protein encoded in ...

On episode #320 of the science show This Week in Virology, Vincent speaks with John Coffin about his career studying retroviruses, including working with Howard Temin, endogenous retroviruses, XMRV, chronic fatigue syndrome and prostate cancer, HIV/AIDS, and his interest in growing cranberries. You can find TWiV #320 at www.microbe.tv/twiv.

Genomes of non-defective viruses range in size from 2,400,000 bp of dsDNA (Pandoravirus salinus) to 1,759 bp of ssDNA (porcine circovirus). Are even smaller viral genomes possible? The subviral agents called viroids provide an answer to this question. Viroids, the smallest known pathogens, are naked, circular, single-stranded RNA molecules that do ...