An alien DNA fragment is to be cloned into the pBR322 vector. The vector is digested at the Sal I recognition site. To successfully create and select the recombinants, which restriction enzyme should be used to cut the alien DNA, and what will be the antibiotic resistance profile of the resulting recombinant cells?

Step-by-step solution

To create a recombinant DNA molecule, both the vector and the alien DNA must be cut with the same restriction enzyme to generate complementary sticky ends. Since the vector was cut with Sal I, the alien DNA must also be cut with Sal I. In the pBR322 vector, the Sal I recognition site is located within the tetracycline resistance gene ( tet^ R ). Insertion of the alien DNA at this site causes insertional inactivation of the tet^ R gene. Therefore, the recombinant cells will lose resistance to tetracycline (become te