GATE BT 2020 • Q20
MCQ • 1 Mark
Section 3: Genetics, Cellular and Molecular Biology
Recombinant DNA technology
Subtopic: Fundamentals of Recombinant DNA technology
Question Statement:
A vector derived from which one of the following viruses is used for high-
frequency genomic integration of a transgene in animal cells?
Options:
-
(A) Adenovirus
-
(B) Adeno-associated virus
-
(C) Lentivirus
-
(D) Herpes simplex virus
5 ---
Step-by-Step Solution & Explanation
### **Official Solution & Concept Analysis (GATE BT 2020 Q.20)**
**1. Governing Concept**:
- **Topic**: Viral Vectors & Gene Therapy
- **Lentiviruses** (a genus of retroviruses, e.g., HIV-1-derived vectors) efficiently infect both dividing and non-dividing / post-mitotic cells, reverse-transcribing their RNA into cDNA that stably integrates at **high frequency into the host cell genomic DNA** via viral integrase.
- Adenoviruses and Herpes simplex viruses remain largely episomal without stable genomic integration; AAV integrates at very low frequencies in the absence of Rep protein.
**2. Option Analysis**:
- **Option (A) [Adenovirus] is INCORRECT**: Remains episomal in host nucleus (transient expression).
- **Option (B) [Adeno-associated virus] is INCORRECT**: Recombinant AAV lacks Rep and remains largely episomal concatemers.
- **Option (C) [Lentivirus] is CORRECT**: Integrates efficiently into host chromatin, conferring stable long-term transgene expression.
- **Option (D) [Herpes simplex virus] is INCORRECT**: Remains latent as episome in sensory neurons.
**3. Final Answer**:
- **Correct Choice**: **C**
Practice This in Real CBT Exam Interface
Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.
Launch CBT Mock Test