Transgenic mice

Application of Transgenic mice as an animal model to detect various human disease

There is an intense connection between animals and human beings. The dependence of man on animals for various purposes is well known like man's use of cattle, sheep, poultry, pig, and fish for milk, eggs, wool, etc. To fulfill his needs, man uses improved varieties of animals for various purposes. Nowadays he carried selective breeding methods for the improvement of animals. This method primarily involves a combination of mating and selection of animals with improved genetic traits to create the desired character in animals. 

Possible manipulation at the genetic level to get the desired character in animals is known as Transgenesis. Transgenesis refers to the phenomenon of the introduction of exogenous DNA into the genome to create to maintain a stable heritable character. Transgenic animals with new heritable characteristics are known as Genetically Engineered or Genetically Modified organisms ( GMOs). Transgenesis is important for improving the quality and quantity of milk, meat, eggs, and wool production. , besides creating drug-resistant animals. 

Transgenic Mice 

The first animal used for transgenesis was a mouse Known as a super mouse. 

Now the question arises in our mind why? The mouse is used for the transgenic process?

The answer is that mouse commonly used for transgenic experiments because 

The mouse was a product of genetic manipulation rather than the normal route of sexual reproduction.

It can be easily handled during experiments.

Mouse produces more eggs (5–10 eggs) as compared to other large domestic animals. ( Note: Superovulated mouse can yield up to 40 eggs) .

Biotechnologists can easily introduce hundreds of different genes into various mouse strains.

With the help of transgenic mice, biotechnologists can understand molecular biology genetics, immunology, and cancer besides creating an animal model for several human genetic diseases like cancer, Alzheimer’s, arthritis, muscular dystrophy, hypertension, neurodegenerative disorder, endocrine disease, and coronary heart disease). 

These are the main reason super Mouse becomes a lot of public attention for various trangenic experiments. In short, we can say the mouse is the animal of choice for transgenic experiments, and transgenic mouse act as researcher friendly. 

For introducing a transgene into mice there are three methods are used:

Retroviral vector method

Microinjection method

Embryonic stem cell method

Names of Transgenic mice that are extensively used as animal models for understanding human disease and for the production of therapeutic agents are :

The Human Mouse

The Alzheimer’s Mouse

The Oncomouse

The Prostate Mouse

The Knockout Mouse

Briefly, discussion on mouse models that are used for the study of several human diseases are :

1. The Human Mouse 

The human mouse is a transgenic mouse with a human immune system. This animal model is a boon for immunologists to detect various experiments for the research of AIDS and SCID. For this purpose, mice with severe combined immunodeficiency were chosen.

SCID( Severe Combined Immunodeficiency Disease )

AIDS( Acquired Immunodeficiency Syndrome)

2. The Alzheimer’s Mouse 

The Alzheimer’s mouse is very useful for understanding the pathological basis of Alzheimer’s disease. During the transgenic process, transgenic mice were developed by introducing the amyloid precursor gene into fertilized egg cells of mice to understand the experimental work on Alzheimer’s disease.

*Alzheimer’s disease is characterized by progressive loss of memory( decline in thinking and judgment), and personality changes due to brain-revealed plaques of dead nerve cells enlarged in a protein called amyloid.

3. The Oncomouse 

The oncomouse was the very first animal to be patented by the U.S. Patent Office in 1988. The oncomouse is genetically altered and is susceptible to cancer. The oncomouse is useful for understanding cancer and evolving modalities for cancer therapy. 

*Onco refers to cancer 

4. The Prostate Mouse 

At 60 years of age, the prostate gland gets enlarged and may become cancerous. The prostate mouse is used to study the concept of prostate cancer. The prostate mice were also patented in 1991.

*Prostate gland, surrounding the urethra of males that is responsible for secreting semen fluid.

5. The Knockout Mouse 

A genetically altered mouse lacks the genes for an entire organ or organ system. A knockout mouse act as a test tube in the laboratory for a biotechnologist that is very useful for human health and welfare. There are several knockout mice have been developed, selected few knockout mice are:

# SCID Mouse

SCID( Severe Combined Immunodeficiency )is a condition characterized by a total lack of immune system cells.SCID Mice were developed by eliminating a single gene and the resultant mice lost the ability to produce B-lymphocytes and T-lymphocytes. 

#Knockout mouse for allergy

The knockout mice were developed for allergy by removing the gene encoding for receptor protein as a result antibodies can’t bind to cells and the mice are unaffected by allergic reactions. The knockout mouse for allergy is very beneficial for millions of sufferers of allergic reactions, spread throughout the world. 

#Knockout mouse for transplantation

To encourage the lack of an immune system in human liver cells can be developed by transplanting sampler human liver cells in the knockout mouse that are very helpful for further study. 

#Knockout mouse with memory loss

By a gene, knockout technique researchers have developed mice that lack the hippocampus ( A specialized area of the brain that believes to carry the memory process). These knockout mice lacked the ability to remember.

#Knockout mouse for retinitis pigmentosa 

In the Knockout mouse for retinitis pigmentosa, the mouse contains a rhodopsin gene that is inactive in nature. The rhodopsin knockout mouse is useful for understanding retinal degeneration, besides evolving therapeutic strategies.  

Transgenic mice are important for the development of therapeutic drugs and possible gene therapies, besides the understanding of the human disease. 

Image Reference :

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