Question

The given figure is the diagrammatic representation of the E. coli vector pBR322. Which of these genes can act as selectable marker?

• A. Ori
• B. $HindIII$
• C. ${amp}^R,{tet}^R$
• D. EcoRI

Answer 1

The correct option is C ${amp}^R,{tet}^R$

Here, $amp$ is the gene that provides ampicillin resistance and tet is the gene that provides tetracycline resistance. Thus, they fulfil the need for being a selectable marker. Both these genes encode the necessary and respective proteins.

Selectable markers are necessary for the maintenance of plasmid inside the cell. The cells having selectable marker genes have a suitable trait, that benefits them in the process of natural selection. Genes that provide resistance to various antibiotics are commonly used as selectable markers.

So the correct answer is "$am{p}^R$, $te{t}^R$".