“Genetic engineering is an interdisciplinary field that deals with genetic modifications. Explore the concept of gene engineering and its advances in 2025.”
Imagine a movie scene where a mad and ugly-looking scientist is working in his laboratory. He is trying to introduce DNA into a person to give him a superpower. He fills a fancy-looking syringe with the DNA and injects it into the person.
The subject is shouting, and an animation flashes, showing that the doctor’s DNA is replacing the subject’s original DNA. Suddenly, something went wrong, and the subject became a beast!
And now, he would be on a mission to destroy the world!
We have seen this storyline many times in movies. However, it does not accurately portray how genetic engineering has been performed. But it shows the concept. That’s genetic engineering!
An interdisciplinary field of genetics or biotechnology dealing with altering an organism’s DNA for economic benefits is known as genetic engineering. Such genetically modified organisms are used for our benefit.
However, in 2025, scientists are trying hard to develop novel genetic engineering approaches to treat human diseases.
Fascinating concept, right?
Let’s dive deeper into genetic engineering and learn its basic concepts, history, procedure, applications and advantages and limitations.
Key Topics:
What is genetic engineering?
Humans have been manipulating plant DNA for thousands of years. Not by genetic engineering, though, but through selective breeding. Several common important plants or fruits we are eating now aren’t in their original form.
They looked different thousands of years ago. A historical reference of selective breeding is around 9000 years old. The Mesoamerican farmers ‘selectively’ bred teosinte wild grass into modern maize (corn).
The popular experiments by Gregor John Mendel (1860) on pea plants are again an example of selective hybridization. It’s also popularly practiced in other parts of the world like in India, China, Japan or the Middle East.
Meaning humans have been altering DNA for thousands of years, unknowingly. That’s only the G. J. Mendel who raised the question, “What is happening here?” and we have the answer now!
Genetic engineering is a collection of techniques used for gene manipulation, the approach scientists use to manipulate an organism’s DNA at a molecular level. By doing so, economically important plant species can be developed and enhanced, microbes can be altered or genetic diseases can be treated.
It has a long history, as we discussed. Interestingly, the word “genetic engineering” wasn’t a scientific word. It was an adaptation from a novel. Let’s know the history of genetic engineering.
History
In 1951, Jack Williamson used the term, ‘genetic engineering’ in the novel “Dragon’s Island.” This was the very first instance the word “genetic engineering” was used in the literature. He was a popular science fiction novelist.
In 1952, James Watson and Francis Crick explained the molecular structure of DNA from the findings of Rosalind Franklin. Now, the chemical and double-stranded DNA structure came into the picture.
During 1970, the restriction enzymes were characterised and known for their site-specific digestion properties.
In 1972, Paul Berg created a recombinant DNA by joining two different viral DNAs (SV40 + lambda virus). This was the very first instance in molecular genetics where scientists intentionally manipulated the DNA.
Now, the science fiction gene manipulation has become reality. The world’s eyes were on genetics, and the gene manipulation experiment was fast-tracked.
In the very next year (1973), Herbert Boyer and Stanley Cohen developed the first genetically modified organism. They incorporated the foreign DNA into the bacterium using the plasmid approach.
Immediately, in 1974, the genetically modified animal model was developed when Rudolf Jaenisch inserted a foreign DNA into mice.
In 1978, recombinant human insulin was prepared, artificially using genetic engineering, followed by the introduction of the first GMO food product, the Flvr Savr tomato, in 1994.
After completely dominating plant and microbial research, genetic engineering was introduced to treat human diseases.
In 2012, Jennifer Doudna and Emmanuelle Charpentier developed a revolutionary and futuristic CRISPR-cas9 gene-editing technology. It has been widely used to treat various genetic disorders.
In 2018, the first gene-edited human babies were born. Using the CRISPR technology, Chinese scientist He Jiankui edited a live human embryo to make it HIV resistant.
However, Jinkui and their colleagues were sentenced to jail for unethically manipulating the human embryo.
In 2020, the mRNA vaccine against COVID-19 was developed using the genetic engineering technique.
This is a short historical re-visit of genetic engineering.
Sounds interesting? Let’s move further.
Definition:
We reviewed literature to understand the concept, read many definitions and come up with our own definition that accurately defines the term. Here it is.
Genetic Engineering is an interdisciplinary field of genetics or biotechnology that deals with the manipulation of an organism’s DNA by introducing, altering or removing a specific gene or DNA sequence to express a desired trait into the target organism.
Background and explanation:
The goal here is to produce a specific trait that we want. For instance, the hard outer cover, the high sweetness and the high-nutrition in fruits. Now, what scientists do;
They isolate a gene from one organism, for instance, a high sweetness gene from one fruit and incorporate it into another organism or species, for instance, in a mango.
Scientifically, it has been performed using a vector. The vector carries the GOI and safely integrates it into the host genome. This vector would be a plasmid, any physical or chemical technique.
Before moving to the technical part, we need to first understand several common terminologies that we use in genetic engineering.
| Terminology | Explanation |
| GOI (Gene of Interest) | The specific gene targeted for modification or study. |
| Vector | A carrier DNA molecule (e.g., plasmid, virus) used to transfer genetic material into a host cell. |
| Target cell | A target cell population whose genome we want to manipulate. |
| Plasmid | A small, circular DNA molecule found in bacteria, often used as a vector in genetic engineering. |
| rDNA (recombinant DNA) | Artificial DNA generated by combining two different DNA from different sources. |
| Cloning | The process of making identical DNA copies. |
Steps and Process:
The genetic engineering process initiates with selecting the gene of interest and lastly, we need to validate the transgene. The steps in this process have been enlisted and explained here.
- Selecting the gene of interest
- Isolation of gene of interest
- GOI insertion into the vector
- Transformation into the host cells
- Modified cells- selection and screening
- Integration into the host genome
- Validation of the transgene
Selecting the GOI:
Gene-of-interest selection is the first and very crucial step in this process. Scientists select the trait they want to enhance or improve. After that, a trait governing gene has been studied.
Bioinformatics analysis has been performed to know the gene length, protein encoded, GC-content, repetitive nature, its role in biological pathways and location on the chromosome, etc.
This information helps scientists decide whether to select the gene for experiment or not. For instance, large gene size and high repetitive sequences usually pose challenges in manipulation.
If analysis is done, it is time to isolate the GOI.
Isolation of GOI:
Genomes contain thousands of genes and billions of non-coding DNA. We need to first isolate our gene of interest from the rest of the genomic DNA from the source.
Restriction digestion, PCR (Polymerase Chain Reaction), cDNA synthesis and cloning are several techniques used in this step. I will give you the link to the article whenever you need to learn more.
Restriction digestion uses a restriction enzyme that selectively cuts DNA at a specific recognition site. If both sides of the GOI have a specific recognition site, it can be isolated by restriction digestion.
PCR is another accurate method to isolate the gene of interest. Here, the GOI has been first mapped; primers are designed to cover it and are used for amplification.
Millions of GOI copies have been created using the PCR. This is the most suitable option for gene isolation and enrichment.
Among the other two methods, cDNA synthesis is the least popular method, whereas gene cloning is the outdated technique.
GOI insertion into the vector:
A vector plays a crucial role in gene integration into the host. Common vectors used in genetic engineering are plasmids, cosmids, bacteriophage, BACs and YACs. This step is further a multi-layered process.
First, we need to select the vectors, followed by the integration of GOI and validation. Restriction digestion and ligation have been employed to integrate the GOI into the vector.
First, the GOI and the vector DNA are digested with the same restriction enzyme to generate either sticky or blunt ends. The complementary ends are joined or sealed using the ligase enzyme. T4 DNA ligase has a high success rate and is widely used.
Afterward, the vector validation is conducted to know if the GOI is incorporated or not. Gel electrophoresis, PCR and DNA sequencing are used for vector validation.
As I explained, it’s a lengthy and complex process, we will discuss that in some other article. Once the recombinant vector is ready, it is time to perform transformation.
Transformation into bacterial cells:
Now, once the vector (for instance, plasmid) has been constructed, it is introduced into the bacterial cells for rapid multiplication. Here, it replicates and generates copies of the recombinant plasmid.
This procedure also avails insert validation as various screening and validation assays are available due to the constant bacterial system. For example, antibiotic resistant screening, fluorescent screening, etc.
If the experiment has been conducted for recombinant protein production, the bacteria can also express the recombinant protein.
After completion of these steps, the recombinant plasmid DNA has been isolated using the plasmid DNA extraction kit or using the vector-specific kit.
Transformation into the host cells:
Now, the idea here is to transfer the recombinant vector into the host cells, then, it will integrate into the host genomic DNA. To do so, various techniques are available. The table below shows a short review of transformation techniques.
| Method | Description | Success rate | Applications |
| Heat shock | Bacteria take up plasmid DNA after sudden temperature changes. | Moderate | Bacterial transformation. |
| Microinjection | DNA is directly injected into the nucleus using a fine needle. | Low | Animal genetic engineering. |
| Electroporation | Electric pulses create pores in cell membranes for DNA entry. | High | Bacterial and mammalian cell transformation. |
| Sonication | Ultrasonic waves increase cell permeability for DNA uptake. | Moderate | Experimental gene transfer. |
| Liposome-mediated transfer | DNA is enclosed in lipid vesicles that fuse with the cell membrane. | Moderate | Gene therapy and drug delivery. |
| Agrobacterium-mediated transfer | Bacteria transfer recombinant DNA into plant cells. | High | Plant genetic engineering. |
| Chemical | Metal ions or chemicals help DNA enter cells but with low efficiency. | Low | Rarely used, mostly for bacterial transformation. |
Plasmid-mediated gene transfer has the highest success rate as it effectively incorporates the GOI into the host genome, comparatively. For instance, in Agrobacterium tumefaciens-mediated transformation, the GOI is inserted into the Ti-plasmid.
This has the highest success rate in plant genetic engineering experiments. Thus, extensively used.
Validation of transgene:
Now, all steps are performed; we need to do two things: first, determine if the GOI is incorporated at the correct location or not, and check the gene expression for GOI.
Again, using either PCR or DNA sequencing, the exact location of gene incorporation can be determined. Primers are designed in a way that covers the boundaries of the GOI and the genomic DNA.
This primer set can be used for either PCR amplification or sequencing to validate the GOI integration.
Now, after that, techniques like quantitative PCR have been used to check the gene expression of transgene, if it is expressed correctly or not. DNA sequencing is used to validate any sequence level alterations if occur in the recombinant DNA molecule.
Once all steps are done, the GMO is ready for commercial use and mass production.
Applications of Genetic Engineering
In this segment, I will explain various applications of genetic engineering— gene manipulation/recombinant DNA/ genetic alterations- in detail.
Genetic engineering has been instrumental in plant and microbial research extensively for years. However, in 2025, scientists are also using it for treating genetic diseases.
Thus, it has a wide range of applications in agriculture, biotechnology, microbiology, crop improvement, animal husbandry, medicine and clinical research. Here, I am reviewing a few common applications.
Plant, agriculture and crop improvement:
Economically important plant species have been improved using genetic engineering. Plants have to face extreme environmental factors. Hence, it can’t be mass-produced.
Herbicidal, drought and viral resistance can now be introduced in plants to improve their growth. For instance, genetically altered wheat, rice and other crops are available in the market with a high water retention capacity and osmotic balance. This makes them more resistant to dry conditions.
Other economically important traits like delayed fruit ripening, altered oil content, pollen production and economically important secondary metabolite production have been enhanced through the same approach.
The introduction of a stable Agrobacterium-mediated T-plasmid system revolutionized this entire industry. This system is capable enough to transfer any gene to the plant species.
| GMO | Modification | Purpose | Benefits |
| Herbicide-Resistant Soybean | EPSPS gene modification for glyphosate resistance | Weed control | Simplifies farming, reduces labor costs |
| Drought-Tolerant Maize | DREB genes introduced | Drought resistance | Ensures crop production in dry regions |
| Virus-Resistant Papaya | PRSV coat protein gene insertion | Virus immunity | Protects crops from PRSV, saves papaya industry |
| Nitrogen-Fixing Rice | Introduction of nitrogen-fixing genes from bacteria | Reduces fertilizer dependency | Increases yield and promotes sustainable farming |
| Salt-Tolerant Wheat | NHX1 gene insertion from Arabidopsis | Tolerance to saline soil | Enables wheat growth in high-salinity environments |
Note
Bt- cotton is the most popular and successful genetically modified cotton species, widely used across the world. It provides resistance against the common cotton insects through ingestion.
Food industry:
Another significantly important application of genetic engineering is in the food industry. Flvr Savr tomato is the very first genetically modified food product developed.
Natural tomatoes have a very soft outer skin that makes them fragile and unable to transport in bulk. GM tomatoes with hard outer skin have been developed using antisense RNA technology. This helped to effectively transport tomatoes.
Golden rice is another classic example of how genetic engineering plays an important role in health and wellness. Vitamin A deficiency is a global concern and causes blindness and immune-related problems in children worldwide.
Golden rice is a genetically altered rice species rich with beta-carotene, a precursor for vitamin A. The GMO version contains the pro-vitamin A gene from the maize and Pantoea ananatis.
A few good examples are discussed in the table below.
| GMO | Modification | Purpose | Benefits |
| Arctic Apple | RNA interference (RNAi) to silence browning enzyme | Non-browning trait | Reduces food waste, improves appearance |
| High-Oleic Acid Soybean | Genetic modification of fatty acid biosynthesis pathway | Healthier oil composition | Produces heart-friendly cooking oil |
| Low-Lignin Alfalfa | COMT gene suppression | Improved digestibility | Increases nutritional value for livestock feed |
| Purple Tomato | Delphinidin (antioxidant) gene introduction | Enhanced anthocyanin content | Provides potential health benefits (anti-cancer properties) |
| Low-Gluten Wheat | Genetic modification to reduce gliadin proteins | Gluten sensitivity reduction | Beneficial for individuals with gluten intolerance |
In the food industry, genetic engineering is beneficial to improve the food quality and nutritional value, fight against adverse conditions, and improve the economic value of the GMO.
Animal husbandry and research:
In animal research, genetic engineering is instrumental for many benefits. It is used to enhance animal traits and health and produce economically important animal traits and proteins. In addition, it is also beneficial to produce disease resistance and higher livestock productivity.
Check out some of the examples given in the table.
| GMO | Modification | Purpose | Benefit |
| PRRS-Resistant Pigs | CRISPR-edited CD163 gene | Provides resistance to PRRS virus | Reduces disease outbreaks and improves animal welfare |
| AquAdvantage Salmon | Growth hormone gene from Chinook salmon | Enhances growth rate | Increases fish production and reduces fishing pressure on wild populations |
| Hypoallergenic Cows | β-lactoglobulin protein deletion | Produces milk without allergenic protein | Allows lactose-intolerant individuals to consume dairy |
| Transgenic Goats | Human antithrombin gene insertion | Produces therapeutic proteins in milk | Enables large-scale production of life-saving drugs |
| Xenotransplantati-on Pigs | Knockout of alpha-gal gene | Prevents immune rejection of organs | Potential source of organs for human transplantation |
Genetic engineering in microbial research:
Much like plant research, the present technology has been extensively applied in microbial research as well.
Genetically modified microbes have been widely used in the production of recombinant protein and vaccines, bioremediation, antibiotic production, probiotic and gut microbe engineering, and valuable biomolecules through synthetic biology.
A few good examples are discussed in the table below.
| Example | modification | Purpose | Benefits |
| Genetically Modified Bacteria for Insulin Production | Insertion of human insulin gene into E. coli | Produce recombinant human insulin | Cost-effective, large-scale insulin production with reduced allergic reactions compared to animal insulin |
| CRISPR-Engineered Lactobacillus for Probiotics | Gene editing to enhance probiotic properties | Improve gut health and treat gastrointestinal disorders | Enhances digestion, improves immunity, and reduces antibiotic resistance issues |
| Microbial Bioremediation Using Pseudomonas putida | Engineering bacteria to degrade toxic pollutants | Clean up oil spills and heavy metal contamination | Environmentally friendly solution for pollution, reduces hazardous waste |
| Vaccine Production Using Saccharomyces cerevisiae | Introduction of viral antigen genes | Develop vaccines for diseases like hepatitis B | Safe and efficient vaccine production without using live viruses |
| Biofuel Production Using Engineered Clostridium Species | Genetic modification to enhance ethanol and butanol production | Develop renewable biofuels as an alternative to fossil fuels | Reduces carbon emissions and provides a sustainable energy source |
Genetic engineering in medicine:
Nowadays, genetic engineering has been extensively instrumental in medicine and health to produce recombinant vaccines and proteins, low-cost drugs, therapeutic molecules, hormones and enzymes.
Recombinant insulin is the best example of the utilization of genetic engineering in modern medicine. This r-insulin is safe to use, cheap, and has the least side effects.
Anti-blood clotting factors like plasminogen are a product of genetic engineering. It is an artificially synthesized enzyme, capable enough to dissolve the blood clot. It is useful for patients with coronary heart diseases, in particular.
Somatostatin and lymphokines are genetically engineered artificial therapeutic proteins used against several diseases.
Traditional vaccines use inactivated viral particles to trigger immune response, however, the approach is contamination-prone and least effective. Vaccines developed using genetic engineering use viral coat protein DNA or mRNA. This approach is more effective and safer.
Various vaccines against smallpox, HSV (Herpes simplex virus), hepatitis and the recently developed COVID-19 vaccine are examples of the use of genetic engineering techniques in vaccine development.
More examples are explained in the table below.
| Example | Modification | Purpose | Benefits |
| Monoclonal Antibodies (e.g., Trastuzumab for breast cancer) | Engineered cells produce antibodies targeting HER2 protein | Treats HER2-positive breast cancer | Highly specific treatment with fewer side effects than traditional chemotherapy |
| Erythropoietin (EPO) | CHO cells genetically modified to produce EPO | Treats anemia in kidney disease and chemotherapy patients | Stimulates red blood cell production, reducing the need for blood transfusions |
| Factor VIII for Hemophilia A | Engineered mammalian cells produce clotting factor VIII | Treat hemophilia A | Reduces bleeding risks and improves quality of life for patients |
| COVID-19 mRNA Vaccine | mRNA encoding the SARS-CoV-2 spike protein | Stimulates immune response against COVID-19 | Highly effective, fast to produce, and does not require live virus |
| HPV Vaccine (Gardasil, Cervarix) | Recombinant DNA technology to produce viral-like particles | Prevents human papillomavirus (HPV) infections | Reduces the risk of cervical and other HPV-related cancers |
| Hepatitis B Vaccine | Yeast genetically modified to produce hepatitis B surface antigen | Protects against hepatitis B infection | Provides long-term immunity, reducing liver disease risks |
Genetic engineering and Gene therapy:
Genetic engineering revolutionized the field of medicine by allowing gene manipulation to treat genetic disease, known as gene therapy. It can repair the faulty gene, introduce functional gene copies and alter gene expression to cure a disease.
Using either viral or non-viral vectors, genetic material can be introduced into the target cells– for instance, AAV9-based Zolgensma. It’s a gene therapy against spinal muscular atrophy that uses the AAV viral vector to introduce functional SMA1 gene copies in patients.
The recently developed CRISPR-cas9 is a type of gene therapy scientists are looking forward to using soon. We already have many FDA-approaved gene therapies available in the market, including the CRISPR-based gene therapy.
We already prepared an entire series on the CRISPR-cas9 gene therapy, you can click the link and read all the articles. “Casgevy” is the first CRISPR-cas9-based gene therapy approved by the FDA to use against sickle cell anemia and is now readily available in the market.
In 2025, hundreds of CRISPR and non-CRISPR-based gene therapies will be approved by the FDA and will be available soon for treatment.
Advantages and limitations of genetic engineering
| Advantages | Limitations |
| Improved Crop Yield | Ethical Concerns |
| Disease-Resistant Plants and Animals | Unintended Mutations |
| Medical Advancements | Environmental Impact |
| Enhanced Nutritional Value | Resistance Development |
| Environmental Benefits | High Costs |
| Industrial Applications | Regulatory Challenges |
| Faster Growth in Livestock | Public Perception and Controversy |
Related article: Genetic Engineering– Importance and Educational Requirements.
Wrapping up:
Genetic engineering belongs to a few scientific endeavours that are still relevant even in 2025. It offered solutions to some of humanity’s most common problems by revolutionizing the medicine, agriculture, microbiology and biotechnology fields.
Initiated to develop novel plant species to treat genetic diseases, it is continuously reshaping and enhancing our lives. In the future, this will also play a crucial role in improving our quality of life by availing quality food, animal products, therapeutics and treatment.
However, there is still a long way to go in this field.
Scientists are searching for better, safer and scalable gene therapy options. CRISPR-cas9 is not yet completely ready to use. In addition, such therapies aren’t fully available due to ethical and legal concerns.
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