Preferential Translation of mRNAs in an mRNA-Dependent Reticulocyte Lysate

Abstract

Messenger RNA competition experiments were performed in an mRNA-dependent [rabbit] reticulocyte lysate using 3 kinds of mRNA: rabbit globin mRNA, calf eye lens mRNA and RNA of turnip yellow mosaic virus. At supersaturating concentrations of mRNA preferential translation of certain mRNA species can be observed. The pattern of mRNA selection by the translational apparatus suggests that the rate of translation of different mRNA species is limited by different components of the reticulocyte lysate. Observations in the cell-free system are strikingly different from previously published mRNA competition experiments in Xenopus oocytes using the same preparations of lens and globin mRNA, in which no selective translation was observed. The restraints on mRNA translation in vitro apparently differ from those in vivo, i.e., in oocytes.