Vector taxonomy — Moloney murine leukemia virus (MoMLV / Moloney–Mu–leukemia virus) is best classified as which type of virus?
Correct Answer: Retrovirus
Introduction / Context:MoMLV is a prototypical gamma-retrovirus widely used in early gene therapy vectors. Understanding its classification informs properties such as integration into host DNA and the requirement for cell division during transduction.
Given Data / Assumptions:
- MoMLV is an RNA virus that uses reverse transcriptase.
- Its life cycle includes conversion of RNA to DNA and integration into the host genome (provirus).
- Classically transduces dividing cells efficiently.
Concept / Approach:Retroviruses are defined by their reverse transcription step and proviral integration. Baculoviruses infect insects; vaccinia is a large DNA poxvirus; adenoviruses are non-enveloped DNA viruses; herpesviruses are enveloped dsDNA viruses with latent replication—none match MoMLV’s key traits.
Step-by-Step Solution:
Identify MoMLV hallmark: reverse transcription and integration.Map this hallmark to the retrovirus family.Select “Retrovirus.”Verification / Alternative check:Retroviral packaging systems (gag/pol/env) are derived from MoMLV, confirming its class.
Why Other Options Are Wrong:
- a/b/d/e: These are different DNA virus families without obligatory reverse transcription integration cycles.
Common Pitfalls:Confusing lentiviruses (a retrovirus subgroup that infects non-dividing cells) with oncoretroviruses like MoMLV that require cell division for nuclear entry.
Final Answer:Retrovirus