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9.2 Uses of transgenic animals:

Transgenic animals are useful in the discovery of new therapy for important human diseases.

Transgenic animals are fundamentally similar to their counter wild type variety except for some genomic heterogeneity.

Transgenic animals are used in the gene therapy experiment to understand the importance of malfunctioned or mutated gene.

Transgenic animals are also used to check the efficacy and safety of the drugs or vaccines used in the clinical trials.

Transgenic mice can be generated to express human targeted gene that can be further used to design new therapy. Transgenic mice can also obviate the use of animals such as monkeys for testing drugs for many human diseases, eg. hypercholesterolemia and HIV.

Some terminology: The  number  of offsprings produced  at one   birth  by an  animal is called Litter size. Normal pregnancy period is called as gestation period. Presence of high levels of   cholesterol   in the blood is called as hypercholesterolemia. LDL receptor (LDLR) present in liver helps to eliminate the excess cholesterol from the body. The deficiency of LDLR in human body leads to increase in blood cholesterol level, condition called as HYPERCHOLESTEREMIA. n hypercholesteremia chances of getting heart attack is higher because of the deposition of cholesterol in the lining of blood vessels. Blood plasma is purified for any unwanted substance in order to prolong the life of a patient (eg low density lipoprotein [LDL] from blood) by a method called PLASMAPHERESIS.

The historical example of a transgenic animal goes to successful generation of a mice where the mouse gene for metallothionein-I was fused to the human growth hormone (GH) and introduced into mice. The resultant transgenic mice showed altered growth characteristics and served as a valuable resource for human disease condition where production of excess growth hormone modulates many physiological processes.