Frederick Noronha (FN)
2004-04-11 20:41:38 UTC
---------- Forwarded message ----------
World Day for Laboratory Animals
24 April 2004
TRANSGENIC FISH COMING
The following article exposes the regulatory vacuum behind the rush for=20
commercial release of transgenic fish.
By Joe Cummins
The tiny zebra fish that lives in aquariums, a popular laboratory animal,=
=20
was genetically modified to produce a fluorescent red pigment, and is being=
=20
promoted for sale as a household aquarium pet, the 'glofish'. The glofish=
=20
caused a stir in the United States because regulation of such transgenic=20
pets is murky and none of the major regulatory agencies: the Food and Drug=
=20
Administration (FDA), the United States Department of Agriculture (USDA) or=
=20
the Environmental Protection Agency (EPA) has been willing to take the lead=
=20
in regulating the glofish (even though USDA does deal with pet animals).=20
The glofish is set to go on sale on 5 January 2004 without regulatory=20
approval.
The FDA announced: 'Because tropical aquarium fish are not used for food=20
purposes, they pose no threat to the food supply. There is no evidence that=
=20
these genetically engineered zebra danio fish pose any more threat to the=
=20
environment than their unmodified counterparts which have long been widely=
=20
sold in the United States. In the absence of a clear risk to the public=20
health, the FDA finds no reason to regulate these particular fish.'
The FDA position that transgenic glofish are substantially equivalent to=20
unmodified fish is hypothetical and no effort has been made to test the=20
transgenic fish in contained, but wild-like environments. Fish pigmentation=
=20
with 'poster' colours is an aphrodisiac to wild fish and may even provide=
=20
protection from predators in certain light conditions, or the pigment=20
fluorescence may signal toxic defence as in the stinging sea anemone from=
=20
which the glofish transgene was prepared and in that way discourage predato=
rs.
The FDA was presumptuous in washing its hands of the regulation of the=20
transgenic zebra fish, which is likely to become a major pest of warm water=
=20
areas.
The release of glofish may signal relaxation of the regulation of=20
transgenic fish now being promoted for commercial release. To ensure that=
=20
transgenic fish do not overpower or seriously pollute the gene pool, both=
=20
promoters and regulators stress the safety of 'sterile' transgenic fish=20
released to bodies of water. Previously, 'sterile' fish are produced using=
=20
synthetic triploid strains of fish produced from treatment of eggs with=20
pressure or temperature shock and with sex hormones. As ISIS reported, the=
=20
sterile triploids were 'leaky' and tend to produce a few fertile progeny,=
=20
which can establish transgenic populations.
In spite of these problems, the transgenic fish are being promoted as the=
=20
first marketable transgenic animals for human consumption. More effort=20
seems to have been spent on promoting the existing defective transgenic=20
fish than on improving them so that they can be safely released for=20
commercial production. Muir and Howard defined conditions under which=20
transgenic fish can cause rapid extinction to wild fish stock, thus posing=
=20
extreme risk; but this has been ignored in the rush to commercialisation.
Development of transgenic fish has focused on a few species including=20
salmon, trout, carp, tilapia and a few others. Salmon and trout are cash=20
crops while the others primarily provide sources of protein. The salmon=20
nearest to commercial release is the Atlantic salmon engineered with a=20
pacific salmon growth hormone driven by the arctic antifreeze promoter gene=
=2E
The rapid growth of that transgenic salmon is achieved not so much by the=
=20
transgenic growth hormone as by the antifreeze gene promoter that functions=
=20
in the cool water desirable for salmon flavour. The commercial release of=
=20
transgenic salmon, even in somewhat contained fish farms, is likely to lead=
=20
to problems similar to those experienced in the Atlantic salmon farms of=20
the northwest Pacific.
A number of studies indicate that salmon produced in sea pens escape and=20
breed with native species, introducing new disease and spreading pollution=
=20
from the culture pens. These problems will probably be amplified in the=20
fast-growing transgenic stocks.
Tilapia fish, native to Africa, are cultured world wide as 'poor man's=20
food', second only to carp as warm water food fish, and exceeding the=20
production of Atlantic salmon (whose market value is twice that of=20
tilapia). Tilapia has been extensively genetically modified and promoted as=
=20
a transgenic fish exclusive for isolated or contained production.
Transgenic tilapia, modified with pig growth-hormone, were three times=20
larger than their non-transgenic siblings. Tilapia genetically modified=20
with human insulin grew faster than non-transgenic siblings, and could=20
also serve as a source of islet cells for transplantation to human=20
subjects. Trout growth hormone was used to produce transgenic carp with=20
improved dressing properties. Such transgenic carp are recommended for=20
production in earthen ponds.
Giant mud loach was produced by linking the mud loach growth hormone with=
=20
its actin promoter. These giant fish are not, technically speaking,=20
'transgenic', as they contain no foreign genes even though the inserted=20
construct is artificial, and pose a paradox for regulators.
Silk moth genes were introduced into Medaka fish to create resistance to=20
bacterial pathogens. Some commercially desirable fish and crustaceans have=
=20
been difficult to genetically engineer because embryonic tissue is=20
difficult to manipulate. But it has been found that the parental gonads of=
=20
such animals could be modified using replication defective pantropic=20
retroviral vectors.
Pantropic vectors can transform an array of species, they are modified=20
forms of the Moloney mouse leukaemia virus used extensively in gene=20
therapy. Such vectors have proven useful in modification of a range of=20
edible marine animals including molluscs.
Animals produced using modified mammalian leukaemia viruses will require=20
extensive testing and long-term evaluation prior to release for human=20
consumption. This is particularly important in view of the leukaemia cases=
=20
found among the handful of successes in human gene therapy, which were done=
=20
with a retroviral vector (see 'Gene therapy risks exposed', Science in=20
Society 19).
The current generation of transgenic fish has not passed the test of=20
complete sterility if released or escaped to the environment. Fish=20
production in inland earthen ponds may prove acceptable for contained=20
transgenic fish culture. But such facilities should be provided with=20
fail-safe destruction of the pond animals in the event of flooding and=20
adequate protection from theft.
Pond commercial culture is effective for carp and tilapia, but more=20
difficult with salmon and trout. Currently, pond culture is suitable for=20
carp and tilapia because the fish are vegetarians, carnivorous salmon and=
=20
trout depend on a diet of fish and fishmeal but the worldwide stock of feed=
=20
fish has diminished and suitable vegetable meat substitutes must be found.
Atlantic salmon (as typical cold water carnivores) cannot thrive on a diet=
=20
of rapeseed oils but the fish can achieve maturity if finished with fish=20
oils at least 20 weeks near the end of their maturity cycle. GM oil rape=20
seed with enhanced production of long chain fatty acids is proposed to=
=20
serve as feed for pond cultured fish. And glyphosate-tolerant GM=20
canola meal has been pronounced substantially equivalent to non-GM canola=
=20
as feed for rainbow trout.
Aquaculture can help feed the world without diminishing ocean resources,=20
but premature releases of transgenic fish stocks will do more harm than=20
good. Bad decisions have plagued aquaculture, resulting in pollution and=20
extensive damage to native stocks. International agencies such as the World=
=20
Bank, the International Development Bank and the Food and Agriculture=20
Organisation of the United Nations have created harm by ill- advised=20
projects that led to damage to native resources and pollution.
Scientists Julio E P=E9rez and Mauro Nirchio of Venezuela, along with Juan =
A=20
Gomez of Panama, commented in Nature: 'However, if the aquaculture industry=
=20
is going to reduce the pressure on wild fish stocks and provide food for=20
the world's growing population, substantial changes must be made by=20
governments, the private sector and international funding agencies. They=20
must protect coastal ecosystems; promote research and development of native=
=20
species; and encourage farming of low-trophic-level fish - those low on the=
=20
food chain. International technical funding agencies can exert great=20
influence in changing practices.'
Without such constructive thinking, the aquaculture industry poses a=20
threat, not only to ocean fisheries but also to itself. - Third World=20
Network Features.
-ends-
About the writer: Joe Cummins is Professor Emeritus of Genetics, University=
=20
of Western Ontario.
The above article is a press release (15 December 2003) of the UK-based=20
Institute of Science in Society (ISIS) <www.i-sis.org.uk>
When reproducing this feature, please credit Third World Network Features=
=20
and (if applicable) the cooperating magazine or agency involved in the=20
article, and give the byline. Please send us cuttings.
World Day for Laboratory Animals
24 April 2004
TRANSGENIC FISH COMING
The following article exposes the regulatory vacuum behind the rush for=20
commercial release of transgenic fish.
By Joe Cummins
The tiny zebra fish that lives in aquariums, a popular laboratory animal,=
=20
was genetically modified to produce a fluorescent red pigment, and is being=
=20
promoted for sale as a household aquarium pet, the 'glofish'. The glofish=
=20
caused a stir in the United States because regulation of such transgenic=20
pets is murky and none of the major regulatory agencies: the Food and Drug=
=20
Administration (FDA), the United States Department of Agriculture (USDA) or=
=20
the Environmental Protection Agency (EPA) has been willing to take the lead=
=20
in regulating the glofish (even though USDA does deal with pet animals).=20
The glofish is set to go on sale on 5 January 2004 without regulatory=20
approval.
The FDA announced: 'Because tropical aquarium fish are not used for food=20
purposes, they pose no threat to the food supply. There is no evidence that=
=20
these genetically engineered zebra danio fish pose any more threat to the=
=20
environment than their unmodified counterparts which have long been widely=
=20
sold in the United States. In the absence of a clear risk to the public=20
health, the FDA finds no reason to regulate these particular fish.'
The FDA position that transgenic glofish are substantially equivalent to=20
unmodified fish is hypothetical and no effort has been made to test the=20
transgenic fish in contained, but wild-like environments. Fish pigmentation=
=20
with 'poster' colours is an aphrodisiac to wild fish and may even provide=
=20
protection from predators in certain light conditions, or the pigment=20
fluorescence may signal toxic defence as in the stinging sea anemone from=
=20
which the glofish transgene was prepared and in that way discourage predato=
rs.
The FDA was presumptuous in washing its hands of the regulation of the=20
transgenic zebra fish, which is likely to become a major pest of warm water=
=20
areas.
The release of glofish may signal relaxation of the regulation of=20
transgenic fish now being promoted for commercial release. To ensure that=
=20
transgenic fish do not overpower or seriously pollute the gene pool, both=
=20
promoters and regulators stress the safety of 'sterile' transgenic fish=20
released to bodies of water. Previously, 'sterile' fish are produced using=
=20
synthetic triploid strains of fish produced from treatment of eggs with=20
pressure or temperature shock and with sex hormones. As ISIS reported, the=
=20
sterile triploids were 'leaky' and tend to produce a few fertile progeny,=
=20
which can establish transgenic populations.
In spite of these problems, the transgenic fish are being promoted as the=
=20
first marketable transgenic animals for human consumption. More effort=20
seems to have been spent on promoting the existing defective transgenic=20
fish than on improving them so that they can be safely released for=20
commercial production. Muir and Howard defined conditions under which=20
transgenic fish can cause rapid extinction to wild fish stock, thus posing=
=20
extreme risk; but this has been ignored in the rush to commercialisation.
Development of transgenic fish has focused on a few species including=20
salmon, trout, carp, tilapia and a few others. Salmon and trout are cash=20
crops while the others primarily provide sources of protein. The salmon=20
nearest to commercial release is the Atlantic salmon engineered with a=20
pacific salmon growth hormone driven by the arctic antifreeze promoter gene=
=2E
The rapid growth of that transgenic salmon is achieved not so much by the=
=20
transgenic growth hormone as by the antifreeze gene promoter that functions=
=20
in the cool water desirable for salmon flavour. The commercial release of=
=20
transgenic salmon, even in somewhat contained fish farms, is likely to lead=
=20
to problems similar to those experienced in the Atlantic salmon farms of=20
the northwest Pacific.
A number of studies indicate that salmon produced in sea pens escape and=20
breed with native species, introducing new disease and spreading pollution=
=20
from the culture pens. These problems will probably be amplified in the=20
fast-growing transgenic stocks.
Tilapia fish, native to Africa, are cultured world wide as 'poor man's=20
food', second only to carp as warm water food fish, and exceeding the=20
production of Atlantic salmon (whose market value is twice that of=20
tilapia). Tilapia has been extensively genetically modified and promoted as=
=20
a transgenic fish exclusive for isolated or contained production.
Transgenic tilapia, modified with pig growth-hormone, were three times=20
larger than their non-transgenic siblings. Tilapia genetically modified=20
with human insulin grew faster than non-transgenic siblings, and could=20
also serve as a source of islet cells for transplantation to human=20
subjects. Trout growth hormone was used to produce transgenic carp with=20
improved dressing properties. Such transgenic carp are recommended for=20
production in earthen ponds.
Giant mud loach was produced by linking the mud loach growth hormone with=
=20
its actin promoter. These giant fish are not, technically speaking,=20
'transgenic', as they contain no foreign genes even though the inserted=20
construct is artificial, and pose a paradox for regulators.
Silk moth genes were introduced into Medaka fish to create resistance to=20
bacterial pathogens. Some commercially desirable fish and crustaceans have=
=20
been difficult to genetically engineer because embryonic tissue is=20
difficult to manipulate. But it has been found that the parental gonads of=
=20
such animals could be modified using replication defective pantropic=20
retroviral vectors.
Pantropic vectors can transform an array of species, they are modified=20
forms of the Moloney mouse leukaemia virus used extensively in gene=20
therapy. Such vectors have proven useful in modification of a range of=20
edible marine animals including molluscs.
Animals produced using modified mammalian leukaemia viruses will require=20
extensive testing and long-term evaluation prior to release for human=20
consumption. This is particularly important in view of the leukaemia cases=
=20
found among the handful of successes in human gene therapy, which were done=
=20
with a retroviral vector (see 'Gene therapy risks exposed', Science in=20
Society 19).
The current generation of transgenic fish has not passed the test of=20
complete sterility if released or escaped to the environment. Fish=20
production in inland earthen ponds may prove acceptable for contained=20
transgenic fish culture. But such facilities should be provided with=20
fail-safe destruction of the pond animals in the event of flooding and=20
adequate protection from theft.
Pond commercial culture is effective for carp and tilapia, but more=20
difficult with salmon and trout. Currently, pond culture is suitable for=20
carp and tilapia because the fish are vegetarians, carnivorous salmon and=
=20
trout depend on a diet of fish and fishmeal but the worldwide stock of feed=
=20
fish has diminished and suitable vegetable meat substitutes must be found.
Atlantic salmon (as typical cold water carnivores) cannot thrive on a diet=
=20
of rapeseed oils but the fish can achieve maturity if finished with fish=20
oils at least 20 weeks near the end of their maturity cycle. GM oil rape=20
seed with enhanced production of long chain fatty acids is proposed to=
=20
serve as feed for pond cultured fish. And glyphosate-tolerant GM=20
canola meal has been pronounced substantially equivalent to non-GM canola=
=20
as feed for rainbow trout.
Aquaculture can help feed the world without diminishing ocean resources,=20
but premature releases of transgenic fish stocks will do more harm than=20
good. Bad decisions have plagued aquaculture, resulting in pollution and=20
extensive damage to native stocks. International agencies such as the World=
=20
Bank, the International Development Bank and the Food and Agriculture=20
Organisation of the United Nations have created harm by ill- advised=20
projects that led to damage to native resources and pollution.
Scientists Julio E P=E9rez and Mauro Nirchio of Venezuela, along with Juan =
A=20
Gomez of Panama, commented in Nature: 'However, if the aquaculture industry=
=20
is going to reduce the pressure on wild fish stocks and provide food for=20
the world's growing population, substantial changes must be made by=20
governments, the private sector and international funding agencies. They=20
must protect coastal ecosystems; promote research and development of native=
=20
species; and encourage farming of low-trophic-level fish - those low on the=
=20
food chain. International technical funding agencies can exert great=20
influence in changing practices.'
Without such constructive thinking, the aquaculture industry poses a=20
threat, not only to ocean fisheries but also to itself. - Third World=20
Network Features.
-ends-
About the writer: Joe Cummins is Professor Emeritus of Genetics, University=
=20
of Western Ontario.
The above article is a press release (15 December 2003) of the UK-based=20
Institute of Science in Society (ISIS) <www.i-sis.org.uk>
When reproducing this feature, please credit Third World Network Features=
=20
and (if applicable) the cooperating magazine or agency involved in the=20
article, and give the byline. Please send us cuttings.