Figure 13.4 Recombinant DNA

In 1973, Stanley Cohen and colleagues pioneered the field of recombinant DNA technology when they demonstrated that biologically functional recombinant bacterial plasmids can be constructed in the laboratory. Specifically, the scientists used restriction enzymes to cut two E. coli plasmids containing a resistance gene for either kanamycin or tetracycline. The plasmids were joined together using the enzyme DNA ligase, and the resulting plasmid was transformed back into E. coli. When the bacteria were plated onto media containing both kanamycin and tetracycline, approximately 1 in 10,000 cells grew, indicating that they were resistant to both antibiotics. To demonstrate that this result represented a genetic transformation and was not from a spontaneous mutation that arose during the experiment, cells that carried individual plasmids for either kanamycin or tetracycline were also plated on media containing both antibiotics. Approximately 1 in 10⁶ cells grew on these control plates, and represented bacteria that acquired antibiotic resistance to the second antibiotic only as a result of spontaneous mutation. These important controls confirmed that the E. coli that grew on the experimental plates represented transformed cells that had taken up the biologically functional recombinant DNA plasmid.

Original Paper

Cohen, S. N., A. C. Y. Chang, H. W. Boyer and R. B. Helling. 1973. Construction of Biologically Functional Bacterial Plasmids In Vitro. Proceedings of the National Academy of Sciences 70: 3240–3244.
http://www.pnas.org/cgi/reprint/70/11/3240

Links

Pray, L. 2008. Recombinant DNA Technology and Transgenic Animals. Nature Education 1(1)
http://www.nature.com/scitable/topicpage/Recombinant-DNA-Technology-and-Transgenic-Animals-34513

University of Arizona: The Biology Project: Recombinant DNA Technology Problem Set
http://www.biology.arizona.edu/molecular_bio/problem_sets/Recombinant_DNA_Technology/recombinant_dna.html

Access Excellence: Inserting a DNA Sample into a Plasmid
http://www.accessexcellence.org/RC/VL/GG/inserting.html

Access Excellence: Cloning into a Plasmid
http://www.accessexcellence.org/RC/VL/GG/plasmid.html

Kimball’s Biology Pages: Recombinant DNA and Gene Cloning
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/RecombinantDNA.html

DNA Interactive: Manipulation
http://www.dnai.org/b/index.html

Biotech pioneers win Lemelson-MIT Prize
http://newsoffice.mit.edu/1996/lemelsonprize-0424

Kimball’s Biology Pages: Transgenic Plants
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/TransgenicPlants.html#Transgenic_Plants

Kimball’s Biology Pages: Transgenic Animals
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/TransgenicAnimals.html#Transgenic_Animals

Phillips, T. 2008. Genetically modified organisms (GMOs): Transgenic Crops and Recombinant DNA Technology. Nature Education 1(1)
http://www.nature.com/scitable/topicpage/Genetically-Modified-Organisms-GMOs-Transgenic-Crops-and-732

Pray, L. 2008. Restriction Enzymes. Nature Education 1(1)
http://www.nature.com/scitable/topicpage/Restriction-Enzymes-545