What is Transgenic Animals? Give its Application

What is transgenic animals? Give the application of transgenic Animals 

Answer :

1. It is now possible to carry out manipulations at the genetic level to get the desired characteristics in animals.
2. Transgenesis refers to the phenomenon of the introduction of exogenous DNA into the genome of an organism.
3. The foreign DNA that is introduced is called a transgene.
4. The animal whose genome is altered by adding one or more transgenes is said to be transgenic.
5. Thus transgenic organisms are genetically engineered or genetically modified organisms, with a new heritable character.
6. Transgenic animals are fertile and carry the transgene in their germ line.
7. The animals used for transgenesis include rats, rabbits, pigs, cows, goats, sheep, fists, etc.
8. Mouse is the animal of choice for transgenic experiments because they have a short generation time.
9. It produces more eggs, a normal mouse produces 5-10 eggs, and the superovulated mouse can yield up to 40 eggs.
10. More than 95% of transgenic animals are mice.

Methods of Transgenesis

1. Transfer of the whole nucleus from a somatic cell of a donor into the enucleated egg of the recipient animal.
2. Transfer of a part of the bisected embryo into the enucleated unfertilized egg.
3. Transfer of chromosome or chromosomal fragments etc.

Application of transgenic animals.

1. Transgenic animals have great benefits to mankind.
2. Due to transgenesis, there is an improvement in the quality and quantity of milk, meat, eggs, etc.
3. Study of diseases: Many transgenic animals help us to understand how genes contribute to the development of disease.
4. With the help of these animals which acts as a model for human diseases like cancer, cystic fibrosis, rheumatoid arthritis, Alzheimer’s disease, etc. new methods of their treatment is possible.
5. Vaccine safety: Transgenic mice are the first to be used to test a newly discovered vaccine before it is used on human beings. Ex. Polio vaccine
6. Bioreactors: By transgenesis, the animals are genetically modified in such a way that they act as bioreactors.
7. Such animals are useful to produce d-1-antitrypsin which is used to treat emphysema.
8. Similarly, phenylketonuria (PKU) is being treated. In 1997 the first transgenic cow was produced called ‘Rosie.
9. This cow produced human protein-enriched milk (2-4 gms/liter).
10. This is a nutritionally more balanced milk product than natural cow milk.
11. Chemical safety testing: Transgenic animals with foreign genes are produced consequently the animals become more sensitive to toxic chemicals.
12. These animals are exposed to toxic chemicals, and toxicity testing in such animals gives fast results.