The use of transgenic organisms for treating human diseases has been a widely debated topic as of late. It is a growing field of research, but it does raise ethical concerns for some. Outlined in this post are ways that transgenesis can be used for the better.
Transgenesis is a form of genetic engineering involving the transfer of genes from one organism to another with the use of recombinant DNA technology. The purpose of this is to make the transgenic organism produce a new gene product or disrupt a host gene at its insertion site. Today, transgenic organisms are used to produce human proteins that can be useful in curing, treating, and preventing various diseases.
What is the process of transgenesis like?
There are multiple methods of transgenesis that can be performed such as microinjection, embryonic stem cell-mediated transfer, and retrovirus-mediated transfer. With microinjection, a gene(s) from one organism is microinjected into the nucleus of a fertilized egg and inserted into a surrogate mother. The resulting offspring should produce the gene product(s) of the introduced transgene. This method often has a high error rate because the transgene is sometimes overexpressed, underexpressed, or not expressed at all. However, this method can be used in a wide variety of species. With the method of embryonic stem cell-mediated transfer, the desired DNA sequence is inserted into embryonic stem cells. These cells are then inserted into an embryo at the blastocyte stage. This method is helpful in inactivating genes. The method of retrovirus-mediated transfer utilizes a virus or plasmid as a vector. In this case, a virus is used to transfer the transgene into the germ cells of the organism. The expression of the transgene varies for each method.
Have you ever wondered how human insulin is made?
One popular product made from the process of transgenesis is human insulin. With the use of recombinant DNA technology, the human insulin gene is inserted into the bacterium E. coli. Then, the transgenic bacteria produce large amounts of human insulin that are then extracted, purified, and sold by companies to people suffering from diabetes. Before this method of producing human insulin was used, animal insulin derived from pigs and cows was administered (Animal insulin, 2019).
Applications of Transgenic Organisms
A notable application of transgenesis is gene therapy. Gene therapy has been used to treat diseases like cancer, cystic fibrosis, hemophilia, and more. In gene therapy, a disease-causing gene is either replaced, inactivated or a new gene is introduced into the body. With a mechanism of transgenesis, genes can be introduced to the human body that produces a new gene product or helps correct a defective disease-causing gene (What is gene therapy?).
Transgenes have applications in plants as well. Genes that help with herbicide, insect, and virus resistance are often incorporated into plants to increase production. With herbicide and pesticide resistant transgenic plants, farmers will purchase fewer pesticides and herbicides. This in turn can help improve the environment. Genes can also be introduced into plants that increase their nutritional value. For example, a transgenic plant may contain a transgene that increases the production of beta-carotene, a precursor for vitamin A. Transgenic plants are also used for the production of antibodies, proteins, and vaccines. Antibodies used against various human diseases like HIV, cholera, malaria, and many more can be produced by transgenic plants. Transgenic potato and banana plants have been used to produce vaccines against certain gastrointestinal tract diseases (Jhansi Rani 2013).
Is transgenesis morally wrong?
Transgenesis is not without error or ethical concerns, however. Everyone has their own moral compass. Some argue that genetic engineering, in general, is not natural or “God’s plan”. Others think that in the wrong hands, it could be more harmful than good. Some are concerned about the welfare of transgenic animals. Some are supportive of transgenesis in some instances compared to others (Ormandy 2011). But, what if this is the step in the right direction to treating the untreatable diseases and illnesses that plague our people? Studying transgenesis in animals and other organisms can help scientists better understand how the genes in humans work. It is not really a question of what scientists are able to do but a question of what is acceptable to do. Because there are so many aspects to genetic engineering, it is difficult to discuss and put limits on how far we can and should go.
Figure 1: The infographic above gives a visual representation of transgenesis and outlines some pros and cons.
Sources
Animal insulin. (2019). Diabetes.co.uk. https://www.diabetes.co.uk/insulin/animal-insulin.html
Buy, M. Transgenic animals. University of Calgary.
Jhansi Rani, S., Usha, R. (2013). Transgenic plants: Types, benefits, public concerns and
future.Journal of Pharmacy Research. https://doi.org/10.1016/j.jopr.2013.08.008
Ormandy, E. H., Dale, J., & Griffin, G. (2011). Genetic engineering of animals: ethical issues,
including welfare concerns. The Canadian veterinary journal = La revue veterinaire
canadienne, 52(5), 544–550. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078015/
What is gene therapy? How does it work? (2017). U.S. Food & Drug Administration.
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