If gene of interest was inserted at Sal I site in Pbr322 THE RESULTING PLASMID WILL CONFER RESISTANCE TO

Options

A. Ampicillin
B. Tetracycline
C. Kanamylin
D. Both (1) & (2)

Answer

To solve the question regarding the insertion of a gene of interest at the Sal I site in the PBR322 plasmid, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of PBR322**:
- PBR322 is a plasmid commonly used in molecular biology, particularly in cloning. It contains genes that confer resistance to two antibiotics: ampicillin and tetracycline.

2. **Identify the Relevant Sites**:
- The plasmid has multiple restriction sites, including Sal I and BamH I. The Sal I site is where the gene of interest is inserted.

3. **Insertion of the Gene of Interest**:
- When the gene of interest is inserted at the Sal I site, it disrupts the function of the gene that was originally present at that site. This process is known as insertional inactivation.

4. **Effect on Tetracycline Resistance**:
- The Sal I site is associated with the tetracycline resistance gene. Inserting the foreign DNA at this site will inactivate the tetracycline resistance gene, meaning that the transformed bacteria will become sensitive to tetracycline.

5. **Effect on Ampicillin Resistance**:
- The ampicillin resistance gene is located on the opposite side of the plasmid and is not affected by the insertion at the Sal I site. Therefore, the bacteria will retain its ability to resist ampicillin.

6. **Conclusion**:
- The resulting plasmid after the insertion of the gene of interest at the Sal I site will confer resistance to ampicillin but will lose resistance to tetracycline.

### Final Answer:
The resulting plasmid will confer resistance to **ampicillin**.