Selected species of 4S RNA of chick embryo cells will hybridize in vitro with 35S RNA of avian myeloblastosis virus. A major tRNA component of the hybridizable 4S RNA is tryptophan tRNA. A hybrid prepared from purified tryptophan tRAN and 35S RNA of avian myeloblastosis virus in vitro is an efficient templateprimer for DNA synthesis catalyzed by reverse transcriptase (RNA-dependent DNA polymerase).
