single-stranded, negative-sense RNA genome
Viral RNA with a base sequence complementary to that of mRNA; during replication it serves as a template for the transcription of viral complementary RNA. Negative-sense (3' to 5') viral RNA cannot be translated into protein directly. Instead, it must first be transcribed into a positive-sense RNA (5' to 3') which acts as an mRNA. Some viruses (influenza, for example) have negative-sense genomes and so must carry an RNA polymerase inside the virion.