Translation of mouse interferon mRNA in Xenopus laevis oocytes and in rabbit reticulocyte lysates

Mouse interferon mRNA, extracted from NDV (Newcastle disease virus)-induced L-929 cells has been translated with high efficiency in Xenopus laevis oocytes and rabbit reticulocyte lysates. The translational efficiency of a crude RNA extract was 10 640 interferon units/mg RNA/hour for the Xenopus oocytes and 4 012 interferon units/mg RNA/hour for the reticulocyte lysates. The translation product fulfilled the usual criteria for mouse interferon, viz. species specificity and neutralization by specific anti-mouse interferon antiserum. Upon injection of crude interferon mRNA into Xenopus oocytes, interferon activity appeared both in the oocyte homogenates and the oocyte incubation medium. When analyzed by velocity sedimentation in formamidesucrose, the mouse interferon mRNA showed a rather sharp peak halfway between the 4 S and 18 S RNA markers, as could be expected from a mRNA which codes for a 20,000 dalton protein.