Structure of a cloned circular retroviral DNA containing a tRNA sequence between the terminal repeats

In the course of analyzing a series of cloned circular retroviral DNAs, we recovered an unusual clone. The molecule consisted of a complete viral genome containing two copies of the long terminal repeat with extra sequences between the repeats. These extra bases proved to be a nearly complete DNA copy of a glycine tRNA, including bases that corresponded to modified and nonpairing bases of the mature tRNA. A model is proposed to account for the formation of the aberrant clone.