Ancient RNA? RT-PCR of 50-year-old RNA identifies peach latent mosaic viroid.

The preservation of macromolecules is at best haphazard. Modern techniques have improved the detection of ancient DNA and proteins, but there is little information on the preservation of RNA. Fifty-year-old dried leaf material showing symptoms of peach calico disease was used successfully in RT-PCRs to amplify peach latent mosaic viroid (PLMVd) RNA and the mRNA for the large subunit of ribulose 1,5-bisphosphate carboxylase (rubisco). These results indicate that naked RNA may be preserved, under suitable conditions, for at least 50 years. The results are discussed in the context of ancient DNA and proteins and the process of fossilization.