Recombinant negative-strand viral RNA templates are described which may be
used with purified RNA-directed RNA polymerase complex to express
heterologous gene products in appropriate host cells and/or to rescue the
heterologous gene in virus particles. The RNA templates are prepared by
transcription of appropriate DNA sequences with a DNA-directed RNA
polymerase. The resulting RNA templates are of the negative-polarity and
contain appropriate terminal sequences which enable the viral
RNA-synthesizing apparatus to recognize the template. Bicistronic mRNAs
can be constructed to permit internal initiation of translation of viral
sequences and allow for the expression of foreign protein coding
sequences from the regular terminal initiation site, or vice versa.