Genetic modified ornamental fish for sale!

By Arnold Dijkstra

alphasure@gmx.net

Millions of people enjoy ornamental freshwater fish, the most spectacular coloured and fluorescent fish are however found amongst saltwater fish. Unfortunately, saltwater fish are relatively expensive to purchase and more difficult to maintain. Biotechnology offers the possibilities to develop freshwater fish with saltwater fish aesthetic qualities. The first commercial results, genetic modified transgenic, brightly red and green fluorescing zebra fish (Danio rerio) are now for sale in several countries worldwide. Backgrounds and risks are discussed.

The glowing zebra fish (Danio rerio)

Zebra fish (Brachyodanio rerio, also known as Danio rerio) are tropical fish native to Asia and worldwide popular as aquarium pets, but also intensively used as research animals in laboratory conditions. They are normally black and silver in colour.

Scientist form the National University of Singapore developed GloFish ™ zebra fish that emit continuous fluorescent light causing brilliant colours, even readily visible under normal daylight.

The effect is caused by fluorescent proteins which are formed in the fish' muscle tissue. A green fluorescent protein (GFP) was originally isolated from the jellyfish (aequorea Victoria) and is intrinsically fluorescent, allowing direct visualization without the need of substrate for chemical reaction. A red fluorescent protein (RFP) was originally isolated from the jellyfish (Aequorea Victoria) and is intrinsically fluorescent, allowing direct visualization without the need of substrate for chemical reaction. A red fluorescent protein (RFP or ds Red ) has been isolated from an IndoPacific sea anemone (Discosoma sp). Using today's biotechnology, scientists were able to isolate the GFP and RFP genetic information (DNA) from the jellyfish and anemone, to insert this information to the zebra fish genetic material and to bring the information towards expression. The result: a red or green glowing transgenic zebra fish.

From Science to Commerce

The fluorescent zebra fish were originally developed to detect environmental toxins in water caused by pollution, the final goal is that the fish will selectively glow in the presence of certain toxins, with a colour depended on the gype of toxin present in the water. As commercial spin-off, York-town Technologies LP, licensed them to sell as pets. The transgenic zebra fish are for sale ($5 – 10) in Asia and most of the USA, further introductions are expected.

Safety and ethics

Scientifically the most important risks to be considered in the use of transgenics

Are:

l         Effects of the transgenic organism for man (when digested, this of course is not an issue for zebra fish).

l         The risk to influence biodiversity, when the transgenic organism is released (or escapes _ Nemo!) in a "natural" population (this means the risk to uncontrolled transfer the inserted genetic material to natural organism). This could play a role when transgenic aebra-fish should be introduced in areas were the fish is native.

l         Direct or indirect effect on animal welfare

Beside the scientific approach, also ethical questions are introduced in the discussion on the development of transgenic organisms.

Based on the available information, the US Food and Drug Administration has issued a statement that they "find no reason to regulate these particular fish". At the same time the United Nations Food and Agricultural Organisation has concluded that "risk attached to the use of genetically modified organisms in aquaculture need to be analysed and quantified in more realistic and reliable ways than so far is the case".

This uncertainty feeds "rumour" around this subject. As expected, Greenpeace strongly questions the sale of transgenic zebra fish. Kistasteful and reprehensible are the "products" presented at the website www.fluorescentpets.com.

The future of transgenic pets

The principles of biotechnology provide many possibilities to change or adept properties of almost any pet. Still many scientific and ethical questions remain to be answered. Therefore we should ask ourselves the principle question: do we want and do we need transgenic pets?

Based on the outcome of this questions we can either decide to buy a transgenic pet or not. If so, we implicit agree to the further development of transgenic pets, whether these are fish, mice, cats or ….

Reference available upon request comments? alphasure@gmx.net

 What are transgenic organisms?

An organism is "transgenic" (or genetically modified organisms once a DNA gene from another organism (animal, bacterium, or plant ) has been inserted. The techniques are already applied widely in agriculture (maize, tomatoes, potatoes, cotton, soy), food industry (enzymes for bread, cheese, beer, vitamin enriched rice), cattle breeding (cow, sheep, goat), pharmaceutical industry (modifications of micro-or-ganisms for medicine production), fish industry (salmon, trout, catfish, shrimps ) and scientific research (mice, rats, zebra fish)

Modification is usually directed towards the improvement of growth and quality, the development of disease resistance and to increase tolerance to environmental variables such as temperature. Despite the scientific and technological advancements, the issue of genetic modification remains surrounded with controversy regarding environmental risks and ethics.

PETS International Magazine (ISSUE 2,2004)