All of the following statements regarding influenza virus structure and genome are correct EXCEPT:

## Influenza Virus Genome Organization **Key Point:** Influenza virus possesses a **negative-sense (antisense) segmented RNA genome**, NOT positive-sense. This is a critical structural feature that distinguishes influenza from many other RNA viruses. ### Correct Statements About Influenza Structure | Feature | Detail | |---------|--------| | **Genome type** | Negative-sense, single-stranded RNA (requires viral RNA polymerase for transcription) | | **Segmentation** | 8 segments encoding 11 proteins | | **Surface proteins** | Hemagglutinin (HA) and neuraminidase (NA) | | **M2 protein** | Ion channel; target of adamantanes (amantadine, rimantadine) | | **Envelope** | Lipid bilayer derived from host cell membrane | ### Why Genome Polarity Matters **High-Yield:** Negative-sense RNA viruses **cannot be directly translated** by host ribosomes. Instead: 1. Viral RNA-dependent RNA polymerase (RdRp) must first synthesize complementary positive-sense mRNA 2. Only then can host ribosomes translate the mRNA into viral proteins This is in contrast to positive-sense RNA viruses (e.g., poliovirus, hepatitis C), whose genome can be directly translated upon entry. **Clinical Pearl:** This genome polarity difference explains why influenza requires active viral transcription machinery in the nucleus, making it dependent on host nuclear functions — a feature exploited by cap-snatching mechanism for mRNA synthesis. **Mnemonic:** **NEG = Needs Enzyme for Gene expression** — negative-sense RNA viruses require their own polymerase before any protein synthesis can begin.