Question

Gene manipulation is a fast emerging science. It started with the development of recombinant DNA molecules. This technology which mostly involves cutting and pasting of desired DNA fragments is based on two most important discoveries in bacteria - presence of plasmid and restriction endonucleases. The science of r-DNA technology took birth when Cohen and Boyer (1973) were able to produce a piece of gene containing foreign DNA introduced into plasmid of E.coli.

(c) Which gene was isolated by Cohen and Boyer and from which bacteria ?

Hint:

They isolated an antibiotic resistance gene from Salmonella typhimurium.

Answer 1

Step 1: Recall the 1973 work:
Stanley Cohen and Herbert Boyer made the first recombinant DNA in 1973.

Step 2: Gene and source:
They isolated an antibiotic resistance gene from the bacterium Salmonella typhimurium.
They linked it with a plasmid of E. coli, which then showed resistance to that antibiotic.

Final Answer:
The antibiotic resistance gene, isolated from Salmonella typhimurium.