Question

Which of the following is commonly used as a vector for introducing a DNA fragment in human lymphocytes ?

• A. Retrovirus
• B. λ phage
• C. Ti plasmid
• D. pBR 322

Answer 1

The Correct Option is A

To determine which vector is commonly used for introducing a DNA fragment in human lymphocytes, let's analyze the options provided:

1. Retrovirus:
   • Retroviruses are widely used in gene therapy for transferring genetic material into the cells. They have the unique ability to integrate their own genetic material into the host cell's genome. This makes them particularly useful for introducing DNA fragments into dividing human cells, such as lymphocytes, as they ensure stable expression.
   • Retroviruses are often engineered to be non-pathogenic and are a popular choice for ex vivo gene therapy, where cells are modified outside the body and then reintroduced.
2. λ Phage:
   • Lambda (λ) phage is a virus that infects bacteria (specifically, E. coli). It is commonly used as a cloning vector in bacteria rather than in human cells.
   • Due to its specificity for bacterial systems, it is not ideal for use in human lymphocyte genetic engineering.
3. Ti Plasmid:
   • Ti plasmid is derived from the bacterium Agrobacterium tumefaciens, which is used in plant genetic engineering.
   • This vector is particularly useful in modifying plant cells but not typically used for human lymphocytes.
4. pBR322:
   • pBR322 is a plasmid vector commonly used in bacterial transformations and cloning applications.
   • It is not suitable for use in human cells or for gene therapy involving lymphocytes.

Based on the above analysis, Retrovirus is the most appropriate and commonly used vector for introducing DNA fragments into human lymphocytes, primarily due to its ability to integrate genetic material into the host cell's genome, making them ideal for genetic engineering in this context.