Detection of tomato mosaic tobamovirus RNA in ancient glacial ice

Tomato mosaic tobamovirus is a very stable plant virus with a wide host ran ge, which has been detected in plants, soil, water, and clouds. Because of its stability and prevalence in the environment, we hypothesized that it mi ght be preserved in ancient ice. We detected tomato mosaic tobamovirus RNA by reverse-transcription polymerase chain reaction amplification in glacial ice subcores <500 to approximately 140,000 years old from drill sites in G reenland. Subcores that contained multiple tomato mosaic tobamovirus genoty pes suggest diverse atmospheric origins of the virus, whereas those contain ing tomato mosaic tobamovirus sequences nearly identical to contemporary on es suggest that recent tomato mosaic tobamovirus populations have an extend ed age structure. Detection of tomato mosaic tobamovirus in ice raises the possibilities that stable viruses of humans and other hosts might be preser ved there, and that entrapped ancient Viable viruses may be continually or intermittently released into the modern environment.