Question

Mention the role of the selectable marker gene in genetic engineering.

Answer 1

Hint: Selectable marker genes are that gene which is required for the association of the plasmid in the cell. Because of the presence of the selective marker, the plasmid becomes valuable for the cell. Under the specific conditions, only cells that contain plasmids with the proper selectable marker genes can withstand.

Complete answer:
-Selectable marker genes are found in plasmids and they help in the selection of the transformants from the non-transformants.
-Transformants are those cells in which plasmid is existing.
-Non-transformants are those cells in which the plasmid is non-existent.
-Selectable marker genes may give resistance to antibiotics especially the ampicillin-resistant and the tetracycline-resistant sites which are seen in the plasmid pBR322.
-If cells are altered with this plasmid, then the cells can be determined by either growing them in a medium comprising ampicillin or tetracycline.
-Simply the cells that have the plasmid (transformed cells) will have resistance for the antibiotic and will be able to flourish in the medium.
-The cells that are not transformed will not be competent to develop in such a medium.
-These genes are typically used to recover transgenic plant cells from non-transgenic cells. These markers are required for maintenance of plasmid in the cell.

Note: Selectable markers genes are always antibiotic resistance genes. These genes mostly help in artificial selection. These genes mainly assigned for the care of the plasmid in the cell Generally, genes that grant resistance to several antibiotics are utilized as selective markers in cloning vectors. Because of the existence of the selective marker, the plasmid becomes beneficial for the cell.