Question

Can you think and answer how a reporter enzyme can be used to monitor transformation of host cells by foreign DNA in addition to a selectable marker?

Answer 1

Selectable markers are used to the difference between a transformant and non-transformant cell while the reporter enzymes are responsible for measuring gene expression.

Step by step answer: A reporter enzyme or a reporter gene is a gene in which scientists attach a regulatory sequence or a gene of interest in any culture. They are responsible for measuring gene expression. A selectable marker is a type of gene which is introduced into a cell’s genome to confer a trait suitable for artificial selection. In recombinant DNA technology, selection of transformed and non transformed cells can be done using reporter genes which translate for reporter enzymes. During the recombinant DNA technology experiment, the foreign gene is attached to a reporter gene. The reporter gene should have a unique feature to produces a visible expression. For example, the Lac Z gene which is a selectable marker and encodes for the enzyme beta-galactosidase can be used as a reporter gene. This gene is not expressed in transformed cells as the product formed by its canalization is not formed in transformed cells and bacterial colonies formed are of white coloration. In non-transformed cells, this gene is expressed and the catalyzed product is formed. This results in the blue coloration of the colony. Thus, reporter enzymes can be used to monitor the transformation of host cells by foreign DNA besides being a selectable marker.

Note: Another protein molecule called green fluorescent protein as a reporter molecule. It is a selectable marker. When this protein is expressed, the cells glow under a blue light-emitting green color. This can also be a proof that the cell transformed.