Incorporation of Radiophosphorus from Labeled Oligodeoxynucleotides into RNA of Mycoplasma in Cell Cultures

Abstract

We have found that various mycoplasma species quickly and efficiently incorporate radiophosphorus into their RNA from labeled oligonucleotides added to the medium. The label can be in any of several positions in an oligodeoxynucleotide, and incorporation also occurs efficiently from labeled RNA. Mycoplasmas also incorporate the radiolabel when they infect a mammalian cell culture; the host cells do not. This incorporation presumably involves uptake of the oligodeoxynucleotide followed by digestion to mononucleotides, conversion to ribonucleotides, and incorporation in new RNA. We believe that the processing of oligodeoxynucleotides by mycoplasma could be a source of artifacts in antisense work in cell culture and could have implications for the development of antisense therapeutics. We also suggest ways to exploit the incorporation phenomenon in mycoplasma testing.