SYNTHESIS OF MOUSE HEMOGLOBIN BETA-CHAINS IN A RABBIT RETICULOCYTE CELL-FREE SYSTEM PROGRAMMED WITH MOUSE RETICULOCYTE 9S RNA

The 9S RNA fraction of mouse reticulocyte polysomes has been purified and shown to direct the synthesis of mouse hemoglobin β- chains. This has been accomplished by adding mouse 9S RNA to a rabbit reticulocyte cell-free system and incubating in the presence of labeled leucine. After the incubation, carrier mouse hemoglobin was added, globin prepared and mouse β-chains isolated by column chromatography. Labeling of the mouse β-chains in the rabbit cell-free system was strictly dependent upon addition of mouse 9S RNA, demonstrating that the fraction contains the mRNA for mouse hemoglobin β-chains. This is the first definitive demonstration of protein synthesis in a mammalian cell-free system under the direction of a mRNA isolated from a different mammalian species. © 1969.