FirstVirus: Finding the first archaeal RNA virus

Evolutionarily prokaryotic organisms branched into two separate domains of life around 3.8 billion years ago, namely the domains of bacteria and archaea. Both DNA and RNA-viruses are known to infect bacteria, but to date no RNA-viruses infecting archaea have been found. Interestingly, some methanogenic archaea encode CRISPR type III-adjacent reverse transcriptases that are hypothesized to be involved in spacer acquisition from RNA viruses, which suggest the existence of archaeal RNA virus infection in situ. We aim to identify and isolate the first archaeal RNA virus using optimized procedures for purification of viral RNA from relevant archaea-rich environments and CRISPR spacer primed reverse transcription to enhance the sensitivity of detection. The project will greatly expand our big-picture understanding about the evolution of RNA viruses within the three domains of life and, more importantly, could shed light on the origin of the diverse RNA viruses that cause disease in eukaryotes.