Summary
Highlights
Genetically modified organisms (GMOs) are organisms whose DNA has been artificially modified by humans using modern genetic manipulation techniques. This involves changing the organism's genome to alter its characteristics. While humans have been selectively breeding plants and animals for thousands of years, modern genetic engineering allows for faster modification by incorporating specific new genes from one species into an unrelated species. Common applications include crops, farm animals, and soil bacteria.
Genetic modification primarily relies on bacteria and their plasmids. Plasmids are tiny circles of DNA in bacteria that can contain one or several genes and can be easily transferred between bacteria. The process involves cutting a desired gene (e.g., human insulin gene) from its original source using an enzyme, then using the same enzyme to open a bacterial plasmid. The desired gene is then inserted into the plasmid, and the modified plasmid is put back into a bacterial cell. The bacteria reproduce rapidly, creating millions of bacteria that produce the desired protein, which can then be harvested and purified.
Examples of GMOs include spider goats, which have the spider silk gene inserted into their DNA, causing them to produce spider silk in their milk. This silk is incredibly strong and light, with potential applications in various fields. Another example involves integrating genes that glow under UV light (e.g., from jellyfish) into animals for medical research. Glow-in-the-dark mice and fish have aided breakthroughs in treating cancer, Parkinson's, and spinal cord injuries, while glow-in-the-dark cats have been used for HIV research. Crops are also genetically modified to be pest-resistant or to have enhanced nutritional benefits, such as additional vitamin A.