Fluorescent fish spark GM response

GM Fish
Spot the GM Fish: some of the
colour variants found that are
the result of crossing GM and
non-GM zebra danios.
Photo: Rissa Williams

The hunt is on for unusually coloured red/pink genetically modified (GM) tropical aquarium fish after MAF Biosecurity New Zealand (MAFBNZ) was alerted to the sale of potentially modified zebra danio (Danio rerio) fish online.

GM status confirmed

Investigators started by determining whether the colouration of the danios in question was the result of dye or genetic modification. MAFBNZ obtained some of the suspect danios and sent them to the GM Inspectorate at the Central Science Laboratory (executive agency of the Department for Environment, Food and Rural Affairs) in the United Kingdom to test for genetic modification. The results showed that the fish contained a red fluorescent protein not found naturally in zebra danios, conclusively demonstrating that these fish were genetically modified.

Why is MAFBNZ responding to the presence of these fish?

GM organisms are defined as new organisms under the Hazardous Substances and New Organisms (HSNO) Act 1996 and are not permitted for importation or release in New Zealand without approval from the Environmental Risk Management Authority (ERMA New Zealand). While a limited number of approvals have been given for research purposes on GM zebra danio fish within approved contained laboratory facilities, ERMA New Zealand has not approved their importation or release for the aquarium pet trade. This means that GM zebra danios are not permitted in the aquarium pet industry and, therefore, these fish are illegally present in New Zealand. MAFBNZ is charged with enforcing any breaches under the HSNO Act.

Response update

The MAFBNZ operation kicked off in Christchurch, in response to reports that GM zebra danios were being bred there and sold via online auctions.

The Christchurch investigations revealed many leads, enabling the response team to contact people who had obtained these fish and arrange for the fish to be euthanased.

The GM fish came into New Zealand as a single consignment earlier this year. A total of 210 red/pink GM zebra danios were sold to 14 pet shops throughout New Zealand. MAFBNZ, with assistance from AgriQuality Ltd, has contacted and interviewed pet-shop managers with the aim of tracking down people who may have bought and/or bred from these fish.

Role of GM zebra danios in science

GM zebra danios have been used extensively as a vertebrate biomedical research model for studying genetics and development, and could be described as the 'fishy' version of rats and mice for use in research laboratories. Their high fecundity, small size, rapid generation time and optical transparency during early development, make them ideal candidates for research. Zebra danios have been used in aquatic toxicity studies, understanding human disease and the screening of therapeutic drugs.

Researchers originally developed the fluorescent zebra danios to be used as pollution indicators in bio-monitoring programmes. The fish were engineered to fluorescence in response to pollutants such as oestrogen, heavy metals and toxins. The fish will immediately display the colour depending on the type of environment the colour has been specified for.

So far, 333 GM zebra danios have been recovered from 16 of 38 properties visited. All fish located have been humanely euthanased using an overdose of an aquatic anaesthetic.

MAFBNZ is enlisting the help of the Federation of New Zealand Aquatic Societies in this response operation. This group is helping MAFBNZ to track down the GM fish by distributing information to its members and instructing them how to contact MAFBNZ if they suspect they have the fish or know someone who might.

How are fluorescent GM zebra danios made?

DNA is sourced from other animals that have naturally occurring fluorescent traits; these can include jellyfish, coral and sea anemones. As the GM zebra danios in question were red, the most likely source of the protein was from red reef coral fluorescent protein. Thefirst coral-derived red fluorescent protein to be extensively utilised was derived from Discosoma striata and is commonly referred to as DsRed.

The construct, or DsRed, is usually introduced into the animal's genome through microinjection or electroporation of the recombinant DNA fragment into fertilised eggs or early embryos. The process of inducing transgenesis is relatively inefficient using microinjection. Only about one percent of microinjected eggs will stably incorporate the DsRed into their genome and subsequently transmit the transgene to progeny. If successful, the end result is offspring that possess a new brightly coloured trait.

During the investigations, MAFBNZ has established that other colour variations of these fish exist. These include red and blue striped variants resulting from a cross between non-GM and GM zebra danios, and a smaller number of bright yellow GM zebra danios. While the yellow-coloured GM zebra danios are similar to the naturally bred golden zebra danio, the GM danio fish are noticeably brighter.

MAFBNZ continues to seek any remaining GM zebra danios in the aquarium trade. While eradicating every last GM zebra danio in the aquarium trade will be difficult, we hope to recover as many of these fish as possible. We need the help of the wider public, in particular the ornamental fish community, to ensure that this happens.

If you think you may have genetically modified danio fish or know of someone who might, please notify MAF Biosecurity New Zealand on 0800 80 99 66.

For further information on GM zebra danios:

Return to:

Page last updated: 30 April 2008