THE STABILITY, TOXICITY AND EFFECTIVENESS OF UNMODIFIED AND PHOSPHOROTHIOATE ANTISENSE OLIGODEOXYNUCLEOTIDES IN XENOPUS OOCYTES AND EMBRYOS

The properties of antisense phosphorothioate and unmodified oligodeoxynucleotides have been studied in Xenopus oocytes and embryos. We find that phosphorothioates, like unmodified oligodeoxynucieotides, can degrade Vg1 mRNA in oocytes via an endogenous RNase H-like activity. in oocytes, phosphorothioate oligodeoxynucleotides are more stable than unmodified oligoeoxynucleotides and are more effective in degrading Vg1 mRNA. In embryos, neither unmodified nor phosphorothioate deoxyoligonuleotides were effective in degrading Vg1 message at sub-toxic doses. © 1990 Oxford University Press.