Transgenic animals


To introduce something new into the human body requires a great degree of unnatural attempts to understand and ensure the safety and potency of medicine or device, However, human subjects cannot be used to experiment medicines for the first time, therefore, the transgenic animals gained their popularity in recent days. During the procedure, the genome of the transgenic animals is deliberately manipulated by using recombinant DNA technology. The unnecessary change in the genetic makeup of an individual sometimes leads to the most dangerous situation called induced mutation which can harm or even kill the animal. The principal aim of the procedure is not to treat the animals but to utilize them as a medium of introducing the artificially cloned genetic materials to check its efficiency before injecting them into the human subjects.  The most common procedure involved in the transgenic process is DNA recombinant technology where the recombinant DNA is transmitted through the germ-line of the animal into the host. Germ-line introduction help to distribute the effect of treatment evenly through all the cells. The most common transgenic animal used in experiments is the mice, however, modern-day experiments have made use of rabbit, pigs and some other animals also. This article describes the process of DNA injection by using transgenic animals.



Transgenic procedures

1. DNA microinjection

Microinjection is the transfer of a cloned gene combinations into the host. Gene cloning is the process in which a gene of interest is located and copied (cloned) out of DNA of an organism which is later modified artificially according to the requirement. Cloning can also be done by taking genes of 2 different species or the same species. Followed by this, the cloned gene combination is transferred to the pronucleus of a reproductive cell through some mediators.


2. Retrovirus-Mediated Gene Transfer

A retrovirus is used as vectors to transfer the cloned and hybridized genetic material into the host cell. This can magnify the degree of biodiversity in the target progeny.


3. Embryonic Stem Cell-Mediated Gene Transfer

Stem Cell-Mediated Gene Transfer is the prior insertion of the desired DNA combinations into an in vitro( into the uterus) culture of embryonic stem (ES) cells. Stem cells are the primordial cells that later differentiated into somatic or germ cells. Consequently, the genetic material of every cell in the body is being altered.



Benefits of transgenic animals

Many transgenic animals are used to identify the safety of a newly released biological or chemical products such as drugs and vaccines. Some of the laboratory tests, therapies, diagnostic tools cannot be directly implemented on the human subjects unless we reckon the possible negative effect of the given sample. However, experimenting on the animals without knowing the outcome is ethically wrong, therefore every effort must be made to judge the outcome of an experiment in advance.



Uses of transgenic animals

1. For genetic study:

This is performed by genetically designing the animal`s genes to understand how they are regulated and what are their influences on human anatomy, physiology, development, and growth. For example, a study of ampicillin-resistant genes can be carried out by modifying the mice`s genes and then inject the drug to see it`s efficacy.


2. In pathology:

Pathology is a branch of medical science to study the disease causation and factors involved in the disease causation. The transgenic animals are so designed to enhance human understanding of disease causation. In the past, many transgenic models and applications have helped in identifying genetic disorders mainly leukaemia and some degenerative illnesses like  Alzheimer’s disease. In the field of toxicology, it is used as a detective agency of toxins.


3. As a product:

Transgenic animals can be used to generate the most expensive biological products through DNA recombination. It is carried out by introducing a portion of artificially coded DNA into the target cells. It is predominantly used in the field of pharmaceuticals to understand product efficacy. It also helped to increase milk yield, meat production and the yield of livestock through injecting genetically engineered hormones to the cattle and its related families.


4. To test the vaccine safety:

For testing the vaccine safety, Guinea pigs and laboratory mice are transgenically used. Vaccines are injected to the animals at lower doses before using them in human subjects. This will help in understanding the adverse effects of a newly introduced vaccine.



Ethical concerns in transgenesis

A. Regulations from governmental organizations:

It is important to obtain a valid legal licence from the government and the administrative department of the concerned area before proceeding. One should understand that it is not an easy job to introduce a drug or DNA as it is potentially risky for animals. Genetically modifying the organisms might even kill the host. Government has set up organizations like GEAC (Genetic Engineering Approval Committee) to delimit the experiments and approve the operations only if they are immensely important at this stage.



B. Patent rights violationBiopiracy):

Biopiracy is the commercial use of biological resources without a legal licence from the regulating bodies. When a product is indigenous to a territory or country, others cannot use them without buying the patent rights from where the product was originally originated. One of the well-known example was the patent rights violation against Indian Basmati rice. India had around 27 documented varieties of Basmati rice. In the year 1997, one of the American companies purchased patent rights on Basmati rice through the US Patent and Trademark Office however many others used them without the knowledge of the US market. 



Some of the questions we need to address here when we experiment on an animal are​

1. Are we exploiting animal species by changing their natural form?

2. Are we trying to blur the lines between individual species by creating transgenic combinations?

3. Are we aware of the future- consequences of the transgenic procedures?

4. Are we really benefiting or harming the mankind? 

5. Are we greedy ? are we using animals for the profit?

6. Are we trying to manipulate the whole nature of human beings which is quite contrary to nature`s law? 

7. Are we the reason for unintended personal, social, and cultural consequences as a result of the procedure?





Course List