The Basic Process of Genetic Engineering
Genetic engineering modifies organisms by directly altering their DNA, the molecule that carries genetic instructions. Scientists identify a target gene, isolate it, and insert it into the organism's genome using tools like restriction enzymes and vectors. This allows for the addition, removal, or modification of specific genetic material to confer new traits, such as disease resistance or enhanced growth.
Key Techniques and Components
Core techniques include recombinant DNA technology, where DNA from different sources is combined, and gene editing tools like CRISPR-Cas9, which acts like molecular scissors to cut and replace DNA segments precisely. Vectors, such as plasmids or viruses, deliver the modified DNA into host cells, where it integrates into the genome and is replicated during cell division.
Practical Example: Engineering Bacteria to Produce Insulin
A common application is producing human insulin in bacteria. Scientists isolate the insulin gene from human DNA, insert it into a bacterial plasmid using restriction enzymes, and introduce the plasmid into E. coli cells. The bacteria then express the gene, manufacturing insulin that can be harvested for medical use, revolutionizing diabetes treatment.
Applications and Real-World Importance
Genetic engineering is crucial in agriculture for creating pest-resistant crops like Bt corn, in medicine for gene therapies treating genetic disorders, and in research for studying gene functions. It enables targeted improvements that traditional breeding cannot achieve, though it requires careful regulation to ensure safety and ethical use.