What is a Transgene?

Mary McMahon
Mary McMahon

A transgene is a section of genetic material from one organism which appears in the DNA of another organism. Depending on a number of factors, the transgene may fail to express, may express in a way different from that observed in the original organism, or may express in the new organism in exactly the same way it did in the original one. A gene is identified as a transgene when it has been sequenced in one species and later identified in another.

Transgenic organisms are often developed for agricultural purposes.
Transgenic organisms are often developed for agricultural purposes.

Some transgenes occur naturally. For example, bacteria are very adept at exchanging genetic material, even across bacterial species, because this allows them to adapt rapidly to changing environments. This is one reason why drug resistance is a concern, because bacteria can not only pass drug resistance on to members of their species, but also potentially to members of other species.

A transgene is a section of genetic material from one organism which appears in the DNA of another organism.
A transgene is a section of genetic material from one organism which appears in the DNA of another organism.

In other instances, transgenes are inserted through genetic engineering. Genetic engineering is used to do everything from creating transgenic mice for laboratory research to developing new crops which will be resistant to drought. In this case, a gene of interest is identified and inserted into the genome of the target organism in the hopes that it will express as desired. For example, headlines were made in the early 21st century when a man claimed to produce a rabbit which glowed in the dark by inserting jellyfish genes into the genome of a rabbit.

A transgene can be passed on to future generations, which is sometimes a cause of concern for researchers. Some people fear that transgenic organisms made in the lab could weaken wild populations of the same animals, or that inserting transgenes could have unintended consequences which will only become apparent when it is too late. In response to this concern, sometimes sterility is created during the process of genetic engineering, as with transgenic crops which are not supposed to be able to reseed themselves.

Transgenes can be used and studied in a number of ways. A transgene may be used, for example, for a purpose such as introducing human DNA into lab animals in order to study human pathology without experimenting on humans. The exploration of gene expression or lack thereof can also be accomplished with the use of transgenes and transgenic organisms. People may be curious, for example, about genes which appear dormant in some animal species, wondering if these genes are relics of ancestors or if they can be induced to express.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


@GlassAxe- An example of how deadly a biological weapon could be, I will use an example of a recent bacterial outbreak in Europe. Recently, Germany experienced an E. Coli outbreak that killed over 1,500 people. The outbreak was one of the deadliest in history, and has raised the eyebrows of scientists at the world bank and the organization that publishes the site you were exploring. The outbreak is a hybrid strain of two different forms of E. Coli that combine to create an anti-biotic resistant super bacterium that kills by causing bloody diarrhea and kidney failure. Almost a third of those who died suffered acute kidney failure and could not be treated by the strongest drugs used to combat bacterial infections.

The Strain could easily have been engineered, and there is increasing worry that these super bugs can be produced by a terrorist state like Iran. The risks from genetic engineering are much bigger than harming a bunch of transgene mice. The negative effects of this technology developed for destructive purposes could wipe out a large portion of the population.

The Spanish Flu infected 500 million (25%) of the world's population and killed between 50 and 100 (3%-6% of world population) million people. This is a mortality rate between 10% and 20%. The European E. Coli outbreak sickened 4,000 and killed 1,500, resulting in a mortality rate around 37%. Imagine what a designer super bacteria or virus could do.


What are some of the transgene technology developments of the last five years? I was recently looking at a site called the Bulletin of Atomic Scientists after hearing about it from a friend.

I had never explored the site or heard anything about the doomsday clock, but thought it would be curious to see what it was all about. One of the concerns listed as a potential for catastrophic societal harm was transgenic and biological weapons.

How can a transgene be weaponized? I thought that transgenic products were mostly genetically modified food organisms. How does this pose a threat to humanity? How can something like food be weaponized? If anyone can help me understand this, I would be interested in learning more.


@Babalaas- I guess I do not understand the topic of genetic engineering enough, because I do not see where social, ethical or environmental issues would arise from the research done in the field. What kinds of detrimental impacts could study in this field cause? The only ethical concern I could think of is whether it is right to breed a transgenic mouse to use for biological testing, but even in this instance, I think that the benefits outweigh the ethical concerns.

Things like improving health, living longer, and feeding people are pretty important. I say we should invest more of our resources into genetic engineering so we can save more people, allow people to live longer, and feed the world's hungry. Without the advancements made in this field, the world would probably be a scarier place.


I find transgenics interesting but terrifying at the same time. The advancements made in transgenics might be some of the most incredible discoveries ever made. Some of these advancements could allow us to live longer, support the world's growing population, and adapt better to our environment.

At the same time, transgenics and biological engineering raise many social, ethical and environmental concerns. I have read about advancements in the field that could make life very difficult for certain groups of people, and completely alter our economy and social structure as we know it. I guess only time will tell whether genetic engineering was a dawn of a new age, or the end of an era. I wonder if 100 years from now, transgenics and genetic engineering will make the planet better for the human race and all of its species. Does any one have any thoughts on this?

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