Fish Story : Biotech Animals: Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

Ethically Speaking

At a time when genetically engineered plant crops have spurred protests in the United States, the use of biotechnology in food-animal production is likely to attract an even larger set of critics because both transgenics and cloning deal with animals.

People for the Ethical Treatment of Animals (PETA), a large animal rights organization headquartered in Norfolk, Va., for example, feels that people shouldn't be tinkering with animals like Frankenstein and is very much opposed to intensive animal agriculture.

In general, CVM's Matheson says that for animal safety, the goal of regulating products of animal biotechnology is to ensure healthful surroundings, proper medical treatment, discovery of any special management measures needed, and freedom from pain and suffering.

Regulating Transgenic Animals

FDA already has the legal authority to regulate most products derived from transgenic animals, whether they are used as drugs, as human food, or as animal feed. Therefore, only guidances or regulations that cover specific aspects of animal biotechnology may need to be added-not whole new statutory frameworks for regulating the products. These guidances will likely address such issues as safety of the target animal and protection of the environment.

Most of the gene-based modifications of animals for food production fall under CVM regulation as new animal drugs. The genetically modified growth hormone for the fish, for example, will be regulated the same way the agency regulates bovine somatotropin, the genetically engineered bovine growth hormone that makes cows produce more milk. Transgenics simply provides another means to add growth hormone to an animal.

"When I speak to folks about the regulation of animal genetic engineering," says Matheson, "the first reaction is often surprise that genetically engineered animals could possibly be viewed as containing new animal drugs." People are surprised, he says, because their experience with animal drugs is limited to products they buy for their pets.

With transgenic salmon, the inserted growth hormone trait is inherited by subsequent generations. With cows, the drug is periodically injected into each one. Either way, products regulated as new animal drugs in the United States are subject to rigorous premarket requirements to determine effectiveness and ensure food, animal and environmental safety.

"One of the good things about regulating transgenics as animal drugs," says CVM director Stephen F. Sundlof, DVM, PhD, "is that we can make sure that the environmental controls and other safety measures are built right into the process." This process includes target animal safety, safety to the environment, and safety for consumers to eat foods derived from genetically engineered animals.

CVM intends to use various approaches, including a contract with the National Academy of Sciences, to identify further environmental safety issues associated with investigation and commercial use of transgenic animals. To do this, the agency will cooperate closely with other federal and state agencies that have related authorities, such as the Fish and Wildlife Service and the National Marine Fisheries Service, in the case of transgenic Atlantic salmon.

Looking to the Future

The agency already is gearing up for the major debates it expects regarding transgenic animals — debates likely to mirror the discussions now underway for bioengineered crops. At this time, no transgenic animals have been approved to enter the human food supply, but a few individual transgenic animals have been allowed to be rendered and used in animal feed.

While it's true that new compounds to combat specific diseases or to optimize the nutritional value of food products can also be created by conventional means, researchers believe that transgenics technology can help make it possible to produce them more quickly, in larger quantities, and ultimately, at lower cost to consumers.

"After over 10 years of examining products on a case-by-case basis," says Matheson, "I can say that the guidance and regulatory structure for animal biotechnology is starting to evolve. I hope we can learn from our experiences with plant biotechnology to make the road a little smoother."

Creating A New Variety of Fish: The Technique to Make 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.

1. Scientists duplicate the DNA carrying the genetic information for the growth hormone.

2. The gene is inserted into a circular piece of DNA called a plasmid that can be reproduced inside bacteria.

3. Next, the plasmids go inside the bacteria.

4. When the bacteria grow in the laboratory, they produce billions of copies of the plasmid carrying the growth hormone gene.

5. After the copies of the plasmid carrying the growth hormone gene have been produced, they are isolated from the bacteria. The plasmid is then genetically edited, changing its circular structure into a linear bit of DNA. The linear DNA is sometimes called a gene cassette because it contains several sets of genetic material in addition to the growth hormone gene.

6. The gene cassette is either directly injected or mixed with fertilized fish eggs in such a way that the eggs absorb the DNA, making the cassette a permanent part of the fish's genetic makeup. Since scientists insert the growth hormone gene into the fish's egg, the gene will be present in every cell in the fish's body.

7. The eggs are allowed to hatch, producing a school of fish in which some are genetically changed and others are not.

8. Fish that now carry the growth hormone gene are identified. Fish with the properly integrated gene are used to create a breeding stock of the new, faster-growing variety.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.