Define transgenic animals. Explain in detail any four areas where they can be utilised.

Transgenic animals are products of genetic engineering and express specific gene(s) from totally unrelated source. Following are the four main areas where they can be utilised.
1. To study normal physiology and development these animals can be used to study as to which factor / gene products are needed at what time of development. By expression of certain genes, they help scientists to understand the normal gene expression at various stages of growth and development.
2. Study of Diseases
Transgenic animals can be created to serve as models for various human diseases. They also help us understand the involvement of various genes in diseases like cancer, Parkinson’ disease etc.
3. Vaccine safety
Transgenic animals can be used to test vaccines like polio vaccine. Transgenic mice have shown promising results in this area and would replace the vaccine testing on monkeys in the years to come.
4. Chemical safety testing
Transgenic animals are created which are more sensitive to certain chemicals / drugs. These are used to study the toxicity or side effects of that chemical / drug. The advantage is that we get results faster