What are transgenic animals? Why are these animals being produced?

Explanation

Those animals whose gones have been altered by genetic engineering are called as transgenic animals. Following are the reasons which explore the benefits of transgenic animals.
1. Normal Physiology and development. These animals are specific for the functions of body and its development as insulin is produced by a specific gene.
2. Study of diseases. Gives us information to understand how genes contribute to the cause of disease, which act as models for human disease and help to treat disease like Rheumatoid, cystic fibrosis, arthritis, Alzheimer.s and cancer.
3. Biological products. The transgenic animals produce useful biological products can be created by the introduction of portion of DNA which code for a particular product. Such as human proteins, e.g. (a-l-anti trypsin) used to treat Emphysema, phenylketonuria ) and cystic fibrosis.
In 1947, first transgenic cow, rosie produced human protein enriched milk (2,4 gms/litre). The milk contains a-Lactalbumin and was nutritionally a more balanced product for human babies than cow milk.
4. Vaccine safety. Transgenic mice are being used vaccine testing after they are used for humans, e.g. Polio vaccine.
5. Chemical Safety Testing. This is known as toxicity safety drugs. The drugs/chemicals are used on cell lines for their toxicity effect later on used in human beings. Transgenic animals are more sensitive to normal animals. So they will give us best results in less time.