Application of Recombinant DNA Technology

Recombinant DNA is DNA that has been altered or edited by scientists. DNA is the genetic material found in our cells; it is the coding for our biological selves. There are several ways that recombinant DNA, or rDNA, can be created. The basic process is that the DNA is cut in the appropriate location and then reconnected to another strand of DNA. Recombinant DNA technology has many applications, from in-utero gene therapy in humans to genetically enhanced crops and animals.

Genetically Modified Plants

Recombinant DNA technology is used is to genetically alter plants by adding or removing genes. Genes are often added to plants to increase the plant's resistance to bacterial or fungal infection, making herbicides less necessary, or to increase the sweetness of fruit. Genes can also be subtracted to slow the process by which the fruit spoils or to modify the color of the flowers.

Transgenic Animals

Another use of rDNA technology is to add an outside gene to the DNA of animals, creating a transgenic animal. These genes are added to the animal before it is born. Genes can be inserted into the animal to alter its protein content--for example, to produce a cow with low-lactose milk. Transgenic pigs might have organs that can be used for human transplantation. Creating disease-resistant animals is another possibility with rDNA technology.

Gene Therapy

Gene therapy in humans is another possible use of rDNA technology. In this process, the gene is added to a virus and then inserted into human cells. Because viruses link up with the DNA strands of the host, the new gene is therefore expressed in the person. (In this type of therapy, the virus has been modified so it does not cause disease.) In cancer patients, genes can be inserted to correct abnormal genes, to introduce a "suicide gene" into the cancer cells or to increase the patient's immunity.

In-Utero Gene Therapy

Another way that rDNA technology can be used is in gene therapy on a fetus. The advantage to using gene therapy in utero is that the fetus has a much higher stem cell count, making it easier to correct genetic abnormalities, such as cystic fibrosis. It may also be used in cases where the fetus is not making a certain protein or enzyme. In-utero gene therapy is done by injecting a virus with the new DNA into the amniotic fluid, which the fetus then takes in by breathing.

Ethics of rDNA technology

Although rDNA technology provides many benefits and advantages, several ethical considerations and controversies are associated with this technology. Many people believe that altering human DNA is immoral and constitutes "playing God." In addition, because this is a fairly new technology, there are questions about the long-term health effects of consuming genetically altered plants and animals.

References

• National Cancer Institute: Gene Therapy for Cancer