Describe each step required to make a gene knock-out in mice.

1. Designing of the target vector.

2. Insertion of the target vector into the embryonic stem cell

3. Selection of the cells

4. Injecting selected cells into the new cells

5. Breeding of mouse with a normal mouse

Explanation:

The target vectors are made by inserting markers into them. The target vector is inserted into ES cells. The vector generally recombined with the target gene and knock-out that gene. Sometimes, recombination of vectors occurs at incorrect place.

The cells survive in the presence of markers only if the target gene is incorporated with target vector. The cells with the target vector are injected into a normal developing embryo of mouse.

The developed mouse will consist of heterozygous knockout cells and its own cells. The normal mouse is bred with this chimeric mouse. The offspring of these mouse are able to transfer knock-out gene to next generation.