Question

Cohen and his coworkers transferred genes from S. aureus to E.coli. Which of the following statement is correct regarding this experiment?

• A. An Escherichia coli plasmid was used to transfer penicillin resistance from S. aureus to E.coli
• B. A Staphylococcusaureus plasmid was used to transfer tetracycline resistance gene from E. coli to S. aureus
• C. E.Coli plasmid was used to transfer tetracycline resistance gene to S. aureus
• D. None of the above

Answer 1

The correct option is A An Escherichia coli plasmid was used to transfer penicillin resistance from S. aureus to E.coli

Cohen and his coworkers for the first time introduced genes belonging to a different species in bacterium E.coli. They used penicillin resistance gene from a plasmid in another bacterium S.aureus. This plasmid was cut using EcoRI.The plasmid had four restriction sites and generated four fragments one of which contained gene of interest , penicillin resistance gene.The E.coli plasmid pSC101 was used as vector which had tetracycline resistance gene. The recombinant E. Coli had dual resistance over tetracycline as well as penicillin.