Effect of defective interfering particles on plus- and minus- strand leader RNAs in vesicular stomatitis virus-infected cells.

Vesicular stomatitis virus-infected cells contain short RNA transcripts, called leader RNAs, which are coded by the exact 3' end of both the minus-strand and plus-strand nucleocapsid templates. The molar amounts of both the plus-strand leader RNA (which is templated from the minus-strand genome) and the minus-strand leader RNA (which is templated from the plus-strand antigenome) were determined both in standard-virus- and mixed-virus-infected cells by using end-labeled genome probes. The results demonstrate that the presence of defective interfering particles in the infecting virus stock decreases the amount of plus-strand leader RNA but increases the amount of minus-strand leader RNA found in the infected cells. In addition, considerably more minus-strand leader RNA per mole of nucleocapsid template is synthesized in mixed-virus-infected cells than plus-strand leader RNA per mole of nucleocapsid template in both standard-virus- and mixed-virus-infected cells.