Question

explain insertional inactivation wing or referring to the chromogenic property of bacterial cell? ......



plz explain briefly ​

Answer 1

Answer:

Explanation:

Insertional inactivation is a technique which is used in a recombinant DNA technology. In this procedure, a bacteria carrying recombinant plasmids or a fragment of foreign DNA is made to insert into a restriction site inside a gene to resist antibiotics. Hence this causing the gene to turn into non-functional or inactivated state. This is how insertional activation occurs.

Let's take an example of PUC19 plasmid vector.In this, the lacZ gene that encodes for beta-galactosidase can no longer be produced upon the insirtion of a foreign gene. Selection or screening is a fundamental process in which once the recombinant DNA is inserted into a particular host cell, it becomes necessary to detect the cells that have received the recombinant or foreign DNA molecules.

This process refers to as screening or selection. It is based on non- expression or expression of certain traits or characteristics.

Insertional activation is an effective method of screening. In this  procedure, one of the genetic characteristics is disturbed by the introduction of foreign DNA.One of the most influential selection methods of recombinant plasmid for the insertional inactivation procedure is a method known as 'BLUE-WHITE' selection method.

In this procedure, the lacZ gene which is a reporter gene is inserted in the vector. The enzyme B-galactosidase encoded by the lacZ gene comprises of a few recognition sites for for restriction enzymes. The B-galactosidase enzyme splits a synthetic substrate x-gal, which is an organic compound abbreviated as BCIG (5-bromo-4-chloro-indolyl-B-D-galactopyranoside) into an insoluble product that is blue in color.

If a foreign gene is introduced into lacZ, the gene will be deactivated.Hence no blue color will develop as B-galactosidase is not produced due to deactivation of the lacZ gene.

                                                             .......Hope this will help you !

Answer 2

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Insertional inactivation is a technique used in recombinant DNA technology. ... An example of this is a pUC19 plasmid vector in which the lacZ gene that encodes for beta-galactosidase can no longer be produced upon the insertion of a foreign gene.

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Hope it helps... ¯\_(ツ)_/¯