Genetically modified organisms (GMOs) are organisms whose genetic material has been changed using genetic engineering techniques, in a way that would not occur naturally. This modification can involve introducing new genes, enhancing existing ones, or deleting specific genetic sequences. While humans have practiced selective breeding for millennia to cultivate desirable traits in plants and animals, modern genetic engineering allows for more precise and rapid alterations.
Scientific Breakthroughs Paving the Way
Modern genetic modification began with scientific breakthroughs in the mid-20th century. In 1953, James Watson and Francis Crick, building on the work of Rosalind Franklin and Maurice Wilkins, described the double-helix structure of deoxyribonucleic acid (DNA). This discovery revealed how genetic information is stored and passed down.
The early 1970s saw the development of recombinant DNA technology, a method that enabled scientists to manipulate DNA directly. In 1972, Paul Berg created the first recombinant DNA molecules by combining DNA from different viruses. In 1973, this was advanced by Herbert Boyer and Stanley Cohen, who successfully inserted recombined genes into bacterial cells, allowing them to reproduce and express the foreign DNA.
Recombinant DNA technology involves cutting DNA from one organism and pasting it into the DNA of another, often using specialized enzymes. This allows for new genetic combinations. The ability to precisely transfer specific genes between different species became the cornerstone for developing genetically modified organisms.
The Dawn of GMOs: First Creations
Early genetic modification focused on bacteria due to their simpler genetic structures. In 1973, Herbert Boyer and Stanley Cohen created the first genetically modified organism, a bacterium resistant to the antibiotic kanamycin. This demonstrated the potential to introduce and function foreign genes within an organism.
Further advancements in bacterial modification quickly followed. By 1978, scientists engineered E. coli bacteria to produce human insulin, a medical application for treating diabetes. This was the first mass-produced human protein using genetically engineered bacteria, approved for medical use in 1982.
The first genetically modified plant was an antibiotic-resistant tobacco plant, created in 1982 or 1983. This involved inserting a gene for antibiotic resistance into tobacco, demonstrating plants could be genetically altered. Soon after, in 1982, the first genetically modified animal, a “supermouse,” was created by introducing a human growth hormone gene, resulting in mice that grew to twice their normal size.
From Lab to Field: Early Commercialization
The transition from laboratory experiments to commercial products began in the early 1990s. China was the first country to commercialize a transgenic crop with the introduction of virus-resistant tobacco in 1992 or 1993. This was an early step in bringing genetically engineered plants beyond research.
In 1994, the Flavr Savr tomato became the first genetically engineered whole food approved for commercial sale in the United States. Developed by Calgene, this tomato was modified to have a longer shelf life by delaying the ripening process. The FDA deemed it as safe as conventionally bred tomatoes, setting a precedent for regulatory approval of GM foods.
The mid-1990s also saw the commercial introduction of herbicide-tolerant and insect-resistant crops, impacting agricultural practices. Monsanto introduced its “Roundup Ready” soybeans in 1996, which were genetically engineered to be resistant to the herbicide glyphosate. This allowed farmers to control weeds without harming crops. Additionally, insect-resistant crops, such as Bt corn and cotton containing genes from Bacillus thuringiensis (Bt) to produce insecticidal proteins, were commercialized in the mid-1990s, offering new pest control options.