Animal biotechnology in use today is based on the science of genetic engineering. Under the umbrella of genetic engineering exist other technologies, such as transgenics and cloning, that also are used in animal biotechnology.
Animal biotechnology in use today is based on the science of genetic engineering. Under the umbrella of genetic engineering exist other technologies, such as transgenics and cloning, that also are used in animal biotechnology.
Transgenics
Transgenics (also known as recombinant DNA) is the transferal of a specific gene from one organism to another. Gene splicing is used to introduce one or more genes of an organism into a second organism. A transgenic animal is created once the second organism incorporates the new DNA into its own genetic material.
In gene splicing, DNA cannot be transferred directly from its original organism, the donor, to the recipient organism, or the host. Instead, the donor DNA must be cut and pasted, or recombined, into a compatible fragment of DNA from a vector — an organism that can carry the donor DNA into the host. The host organism often is a rapidly multiplying microorganism such as a harmless bacterium, which serves as a factory where the recombined DNA can be duplicated in large quantities. The subsequently produced protein then can be removed from the host and used as a genetically engineered product in humans, other animals, plants, bacteria or viruses. The donor DNA can be introduced directly into an organism by techniques such as injection through the cell walls of plants or into the fertilized egg of an animal.
This transferring of genes alters the characteristics of the organism by changing its protein makeup. Proteins, including enzymes and hormones, perform many vital functions in organisms. Individual genes direct an animal’s characteristics through the production of proteins.
Cloning
Scientists use reproductive cloning techniques to produce multiple copies of mammals that are nearly identical copies of other animals, including transgenic animals, genetically superior animals and animals that produce high quantities of milk or have some other desirable trait. To date, cattle, sheep, pigs, goats, horses, mules, cats, rats and mice have been cloned, beginning with the first cloned animal, a sheep named Dolly, in 1996.
Reproductive cloning begins with somatic cell nuclear transfer (SCNT). In SCNT, scientists remove the nucleus from an egg cell (oocyte) and replace it with a nucleus from a donor adult somatic cell, which is any cell in the body except for an oocyte or sperm. For reproductive cloning, the embryo is implanted into a uterus of a surrogate female, where it can develop into a live being.
Other Technologies
In addition to the use of transgenics and cloning, scientists can use gene knock out technology to inactivate, or “knock out,” a specific gene. It is this technology that creates a possible source of replacement organs for humans. The process of transplanting cells, tissues or organs from one species to another is referred to as xenotransplantation. Currently, the pig is the major animal being considered as a viable organ donor to humans. Unfortunately, pig cells and human cells are not immunologically compatible. Pigs, like almost all mammals, have markers on their cells that enable the human immune system to recognize them as foreign and reject them. Genetic engineering is used to knock out the pig gene responsible for the protein that forms the marker to the pig cells.
According aboutbioscience