Question

Define insertional inactivation.

Answer 1

Insertional inactivation:

1. Insertional inactivation technique of the recombinant DNA technology is used to select bacteria which carry recombinant plasmids; a fragment of foreign DNA is inserted into the restriction site within a gene for the antibiotic resistance, thus causing such gene to become nonfunctional.
2. It is often used to identify the recombinant vectors in gene cloning & in turn to distinguish a recombinant vector from a non-recombinant vector.
3. For eg, insertion of a piece of foreign DNA into the cloning site which is located on an antibiotic-resistant gene on vector can also lead to loss of the antibiotic resistance phenotype by insertional inactivation.
4. This recombinant vector will, therefore, specify antibiotic sensitivity, whilst non-recombinant vector will specify antibiotic resistance.