Transgenic animals are animals that have had a foreign gene deliberately inserted into their genome using recombinant DNA methodology. The first transgenic mice were created in 1980, and the first cloned mammal, Dolly the sheep, was born in 1996. There are three main methods for creating transgenic animals: DNA microinjection, embryonic stem cell-mediated gene transfer, and retrovirus-mediated gene transfer. Transgenic animals produce useful products like monoclonal antibodies, blood clotting factors, and human milk proteins. They are used for medical research, toxicology studies, pharmaceutical production, and analyzing gene expression regulation. However, some ethical concerns exist regarding animal suffering during transgenic research experiments.
2. Transgenic Animal
• Transgenic animals are animals that have
had a foreign gene deliberately inserted
into their genome.
• The foreign gene is constructed using
recombinant DNA methodology.
• Here is the picture of two transgenic mouse
that are genetically modified by having a
green fluorescent protein and it glows
under blue light.
3. Timeline and key events
• In 1929, Jackson memorial laboratories developed mice to study cancer and other diseases
• In September 1980, the first mice was created by recombinant DNA technology.
• In November 1980, Capecchi published a technique to inject DNA directly into the nuclei of
cultured mammalian cells by using glass micropipettes.
• On July 5, 1996, the first cloned mammal (Dolly, the sheep) was born and the work done by
Wilmut.
• In September 2006, the first human monoclonal antibody drug approved.
• On September 23, 2015, Beijing Genomic Institute created micropigs with the help of TALENs
gene editing technique.
• On October 5, 2015, US Scientists from Harvard University modified 60 genes in pig embryos
to create pig organs that are suitable for humans.
4. METHODS FOR CREATING TRANSGENIC ANIMALS
• There are three basic methods by which we can produce transgenic
animals:
1. DNA Microinjection.
2. Embryonic stem cell-mediated gene transfer.
3. Retrovirus-mediated gene transfer.
9. PRODUCTS FROM TRANSGENIC ANIMALS
• Below are some of the products gained through transgenic technology and their
source.
1. Goats
• Monoclonal Antibodies (MAbs)
• Tissue Plasminogen Activator (tpa)
• ATryn
2. Mice
• MAbs
• Antithrombin proteins
• HSA (Human Serum Albumin)
• Beta interferon
• Fibrinogen
• Prolactin
10. PRODUCTS FROM TRANSGENIC ANIMALS (Cont..)
3. Cows
• Factors VIII (A blood clotting protein, also known as Anti-haemophilic factor)
• Recombinant antithrombin III (rATIII),
• Human milk protein
• Recombinant HSA.
4. Rabbits
• Human erythropoietin
• Recombinant human C1 inhibitor (used to treat Hereditary angioedema)
• TPA
• Alpha glucosidase (Antidiabeutic drug)
• Human growth hormone.
11. APPLICATIONS OF TRANSGENIC ANIMALS IN
BIOTECHNOLOGY
• Transgenic animals are used in medical research.
• Transgenic animals are also used in the field called toxicology as a source of
detection of toxicants.
• They are also used in Biotechnology as they produce specific proteins.
• They are also used in Xenografting.
• In molecular biology, they are used for analyzing regulation of gene expression.
• Transgenic animals have a great role in pharmaceutical industry, They are used
for drug testing and drug production.
12. ETHICAL ISSUES
• When we move to the genetic modification of humans and animals,
more objections regarding ethics are recorded. That’s because, with
the advancement in transgenic animal technology more animals are
used for research purposes.The ethical concern regarding animals is
that they have to suffer during our research and it is against animal
rights.
13. FUTURE PROSPECTS
• Transgenic technology in making transgenic animals is quite inefficient and
expensive.
• Genes can only be introduced into an animal without any control on the site of
integration. So, more studies are needed to improve the success and controlled
positioning of integration of transgenes in the future.
• Scientists are also finding some ways to create organs by Xenogenic cells that can
be transplanted into humans.
• Scientists are improving the quality and quantity of the products obtained from
transgenic technology.
• Other improvements that are going on in transgenic animal technology include
artificial chromosomes , inducible genes and improvement in nuclear transfer
techniques.