What are Transgenic Animals?
Transgenic animals are animals that have had foreign gene injected into their genome through the techniques of genetic engineering. The result is the birthing of genetically modified animals.
What are the methods of creating transgenic animals?
There are three principal methods used for the creation of transgenic animals.
a) DNA microinjection
this method also known as physical transfection is direct microinjection of DNA of a different or same species into the pro-nucleus of a fertilized ovum. This process can be random and there is a high chance that injected gene will not insert itself into a site on the host DNA that will permit it’s expression. This is one of the first methods that proved to be effective in mammals and has a major advantage since it’s applicable to a wide variety of species.
b) Embryonic stem cell-mediated gene transfer
Embryonic stem cell-mediated gene transfer involves prior insertion of desired DNA into totipotent stem cells from the embryo. The result is chimerThis method is important for the study of genetic control of developmental process.
c) Retrovirus-mediated gene transfer
Retroviruses are commonly used as vectors, an organism that transmits a disease from one animal to transfer genetic material into the
cell (using their ability to infect host cells.) A retrovirus carries it’s genetic information in the form of RNA insured of DNA. Organisms developed from this method are chimeric for not all cells carry the retrovirus.
What are the uses for transgenic animals?
Transgenic animals are used in the laboratory for research and experiments. Over 95% of those used are modified rodents, mostly mice. They play an important role as tools for researching human disease, cure for such diseases, being ablate understand gene function and to see the progress as well as response to therapeutic interventions. Mice have also been genetically modified to be able to produce human antibodies for uses as therapeutics.
Mice are the main choice of transgenic animals because it’s genome is similar to humans; Psycho
logic and behavioural test performed on these mice can be extended to human diseases. Mice are also able to reproduce quicker and this becomes an advantage for the offspring of transgenic animals can differ from each other resulting in more data that can be studied.
Examples
Transgenic cows: Transgenic cows have been found to produce to lactoferrin which can be found in the immune system which can be used as a additive to infant formula. Also a natural protein produced in the milk of transgenic cows can kill bacteria that cause animal mastitis.
Breeding: Traditional breeding can be take a long time and is a difficult task; when technology using molecular biology was developed it was possible to develop traits in animals in shorter time.
Xenotransplantation: Pigs have organs like humans in size and their tissues age must faster. Hypothetically transgenic pigs may provide the transplant organ needed. Currently this treatment is delayed by a pig protein that can cause donor rejection but there are research done to replace with human protein and remove pig protein.
Disease: By genetically modifying DNA, the animals can produce human drugs like insulin, vaccines and some other; they can be used by diabetes patients who need insulin as well as patients with diseases such as sickle cell anemia.
Transgenic animals are emerging faster. They have been a role in help finding cures for diseases and as the research extends there will be more cures in a more efficient and harmless way.
Definitions
Totipotent stem cells: stem cells that can develop into any type of specialized cell
Lactoferrin: multifunctional protein found in bodily fluids, bactericidal and also have iron properties.
Animal mastitis: inflammation of the mammary gland in the great or udder
Sources
http://people.ucalgary.ca/~browder/transgenic.html
http://www.whatisbiotechnology.org/science/transgenic
https://www.bio.org/articles/genetically-engineered-animals-frequently-asked-questions
http://connectusfund.org/9-biggest-pros-and-cons-of-transgenic-animals
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/TransgenicAnimals.htmlhttp://www.biologydiscussion.com/animals-2/transgenic-mouse/methods-of-producing-transgenic-mouse-with-diagram/12133
http://www.actionbioscience.org/biotechnology/margawati.html