What would happen to an RNA virus if its genome were placed in a bad neighborhood? The answer is that fitness plummets. RNA virus populations are not composed of a single defined nucleic acid sequence, but are dynamic distributions of many nonidentical but related members. In the past I have referred to these populations as quasispecies but …
We have previously discussed the idea that viruses originated from selfish genetic elements such as plasmids and transposons when these nucleic acids acquired structural proteins (see A plasmid on the road to becoming a virus). I want to explore in more detail the idea that the structural proteins of viruses likely originated from cell proteins (link to …
Plasmids have been discovered that can move from cell to cell within membrane vesicles in a species of Archaea (link to paper). They provide clues about the origin of virus particles. Electron microscope analysis of the culture medium from Halobrum lacusprofundi R1S1, an Archaeal strain from Antarctica, revealed spherical particles which were subsequently shown to …
Sharon Isern and Scott Michael return to TWiV for a Zika virus update, including their work on viral evolution and spread, and whether pre-existing immunity to dengue virus enhances pathogenesis. Click arrow to play Download TWiV 454 (65 MB .mp3, 108 min) Subscribe (free): iTunes, RSS, email Become a patron of TWiV! Show notes at microbe.tv/twiv
Could ancient host proteins contribute to the replication of a modern virus? The answer is, not very well (link to paper). Viruses are obligate intracellular parasites, which means that they have to get inside of a host cell to produce more viruses. The genomes of all viruses, even the biggest ones, do not encode anywhere …
Ben tenOever joins the TWiVoli to discuss the evolution of RNA interference and his lab’s finding that RNAse III nucleases, needed for the maturation of cellular RNAs, are an ancient antiviral RNA recognition platform in all domains of life. Click arrow to play Download TWiV 450 (58 MB .mp3, 96 min) Subscribe (free): iTunes, RSS, email Become a patron of TWiV! Show …
