I hope we can learn from our experiences with plant biotechnology to make the road a little smoother. Carol Lewis is a staff writer for FDA Consumer. Transgenic Animals Breeders can now use the tools of biotechnology to introduce new characteristics into animals. For example, researchers have figured out how to give a type of salmon a gene that directs the production of a growth hormone, causing the fish to grow to full size in substantially less time. Here is an outline of the steps needed to introduce the new growth hormone gene into the salmon.
Scientists duplicate the DNA carrying the genetic information for the growth hormone.
The gene is inserted into a circular piece of DNA called a plasmid that can be reproduced inside bacteria. Next, the plasmids go inside the bacteria. When the bacteria grow in the laboratory, they produce billions of copies of the plasmid carrying the growth hormone gene. After the copies of the plasmid carrying the growth hormone gene have been produced, they are isolated from the bacteria. The linear DNA is sometimes called a gene cassette because it contains several sets of genetic material in addition to the growth hormone gene.