1972

Genetic Engineering

Paul Berg (b. 1926)

When we think about engineering, we generally think about creating a new object: a new building, a new device, a new mechanism. Genetic engineering is a different type of endeavor. Here we are taking an existing system that is quite complicated and that we do not completely understand—a genome—and we are tinkering with it. Genetic engineers add new genes to a genome to create new behaviors.

The predecessor to genetic engineering is selective breeding. Breeders select desired traits. With selective breeding we have created all the various breeds of dogs.

But genetic engineering, which appeared in 1972, when American biochemist Paul Berg created the first recombinant DNA molecules, is something altogether different: Engineers are injecting new genes into genomes in ways nature could never accomplish. For example, Berg combined two viruses. Other more recent applications have included a jellyfish gene that produces a green fluorescent protein added to a fish or a mouse, creating fluorescent mice. A gene that makes a plant immune to an herbicide gets added to soybean plants so that the herbicide won’t kill them.

In one of the most bizarre examples, genetic engineers took genes for producing spider silk and added them to goats. The proteins of spider silk appear in the milk of a female goat. The goal was to extract the proteins to create super strong, highly elastic materials.

There are different ways to inject the genes of one organism into another, and the gene gun is one popular tool. The technique is so simple, it is amazing that it works. The gene to be injected is added, in liquid form, to tiny particles of tungsten or gold. The particles are shot out of a gun, shotgun style, at a petri dish full of target cells. Some of the cells get punctured, but not killed, and they pick up the new gene.

By injecting genes from one organism into another, genetic engineers are able to create new organisms. One of the most beneficial examples is human insulin produced by E. coli bacteria. Developed in the 1980s, genetically engineered insulin is used by millions of people today.

SEE ALSO AK-47 (1947), Green Revolution (1961).

Glofish, the first GMO designed as a pet, was first sold in the United States in December 2003.