GM mosquito may help beat malaria

Rick Weiss

Washington Post/ The Guardian Weekly 30-5-2002, page 28

Scientists in Cleveland for the first time have created genetically engineered mosquitoes with a reduced capacity to transmit malaria. The feat points to the possibility of disrupting the scourge by releasing gene-altered insects in Asia and Africa, where the disease kills about two million people every year, most of them children younger than five. But that prospect has alarmed some scientists and others who fear that such a program could trigger ecological disruption and ultimately increase, rather than decrease, the global burden of disease.

Experts said the advance has also brought renewed attention to the fact that the United States has yet to promulgate regulations limiting the environmental release of genetically engineered insects capable of transmitting human or animal diseases.

The new work, published in the journal Nature last week, is the cul mination of 15 years of efforts by several competing teams trying to gain control over the genetic machinery of the mosquito. Although scientists had previously managed to insert various genes into the insect, none until now had made a mosquito that blocks development of the malarial parasite inside the insect's body.

That parasite, a single-cell creature called plasmodium, must pass through a mosquito's gut and be re-injected via mosquito saliva into humans or other animals to complete its life cycle. Control of the disease has been difficult because plasmodium has developed resistance to medicines, mosquitoes have become resistant to insecticides, and efforts to find an effective vaccine have failed.

Taking a new tack, Marcelo Jacobs-Lorena of Case Western Reserve University and his colleagues identified a small protein that binds tightly to a mosquito's gut lining. The team then engineered mosquitoes with a gene that allows the insects to produce that protein after ingestion of a blood meal. In experiments, most plasmodium cells failed to pass through the gut lining and could not travel to the salivary glands. When the team allowed the mosquitoes to feed on malaria-infected animals and later bite uninfected ones, disease transmission was about 80 percent less likely than with normal mosquitoes.

Jacobs-Lorena suggested that scientists could knock down wild populations of mosquitoes with insecticides, then repopulate the area with laboratory-reared gene-altered ones. But he admitted five to 10 years of work might be needed first.

But others expressed relief that the work might progress slowly, saying recent experiences with gene-altered crops teach that extreme caution is warranted. Andrew Spielman, a professor of tropical public health at Harvard University, said it would be ecologically unwise and probably medically useless to release engineered mosquitoes in malarial areas.

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Scientists create the first GM monkey

Washington Post/ The Guardian Weekly 18-1-2001, page 32

The Guardian Weekly 18-1-2001, page 32

Scientists have created the first genetically modified monkey, an advance that could lead to customized primates for medical research and also brings the possibility of genetic manipulation closer than ever to humans.

The researchers made the monkey by splicing jellyfish genes into eggs of rhesus monkeys, just to see if their techniques would work. In the future they hope to produce animals with genes that cause Alzheimer's disease, breast cancer, hereditary blindness and other ailments, so they can test new therapies and vaccines.

"There are fantastic discoveries now being made from studies of human diseases in mice," said Gerald P. Schatten, who with Anthony W.S. Chan led the research at the Oregon Regional Primate Research Center in Beaverton. He went on: "We are optimistic that genetically modified primates can translate some of those discoveries in mice safely and swiftly to people."

Scientists have made gene-altered fruitflies, rabbits, sheep, goats, cattle, pigs and other animals since the first such animal, a mouse, was created in 1976. The work involves adding genes from one species into eggs or early embryos of another species, so the foreign DNA ends up in many or all of the developing animals' cells.

The creation of the monkey - named ANDi, a backward acronym for "inserted DNA" - marks the first time anyone has genetically altered a primate, the group of animals that in cludes monkeys, apes and humans. The method did not work perfectly; the genes can be found throughout the monkey but are mostly not working. But the work gives some credence to fears that scientists may one day use similar techniques to add desirable traits to human embryos, heralding an era of "designer babies."

Already, some fertility clinics offer tests that allow parents to choose embryos free of unwanted traits (such as disease genes) or carrying desirable traits (such as a tissue type that will make the newborn a useful organ donor for a sibling). But although some coveted human genes have been discovered - such as the gene for human growth hormone, which could help a child grow to otherwise unachievable height - no one has inserted such a gene into a human embryo, both because of ethical concerns and because there has not been a monkey model to practice on.

The gene-altered monkey, described in this month's issue of the journal Science, was born in Oregon in October. The jellyfish DNA in its genes has no medical value but is a popular tool with genetic engineers because it makes animals glow green when they're exposed to blue light, offering quick and dramatic evidence that a gene-transfer method works. A stillborn monkey in the Oregon experiment did have fluorescent green fingernails and hair. But its live counterpart does not glow, even though tests show the jellyfish genes are present. That means the foreign genes are functioning poorly or not at all, experts said, and suggests that the technique is not refined enough to make truly useful gene-altered monkeys, much less genetically enhanced humans.

Several scientists doubt the method will ever work well, saying that newer techniques under development offer more promise for making genetically altered monkeys.

Some critics, opposed to genetic modification of humankind's close cousins and concerned about a slide down an ethical slope, said that, even if the method worked in monkeys, they would oppose its use. "Before, it was mice. Now, monkeys, both cloned and gene-altered," said Eric Kleiman, research director of Defense of Animals, an international animal advocacy group based in Mill Valley, California. "It's pretty clear who is next. And it will be just as reprehensible when people are manufactured to suit experimenters."

Schatten said he opposes any human applications. "We certainly don't support any extrapolation or extension of this kind of work to human beings," he said. * Noah, a rare, cloned wild ox or gaur, was born to an Iowa farm cow named Bessie last week, only to die two days later from a common bacterial infection, say scientists. "We're sorry we lost an animal," said Philip Damiani, a scientist with Advanced Cell Technology of Worcester, Massachusetts, who conducted the experiment. "But we were able to prove the technology will work to produce a cross-species offspring. Our people need to realize they achieved a major breakthrough."

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Cloned animal products 'safe to eat' but not from GM animals
Wednesday, 21 August, 2002, 16:45 GMT 17:45 UK
BBC Science Correspondent

Richard Black

http://news.bbc.co.uk/1/hi/sci/tech/2207697.stm

An influential committee of scientists in the USA has declared that eating food made from cloned animals appears to be safe. However, it says that products made from genetically-modified animals could pose a risk to human health.

It also believes that animals created both by cloning and genetic modification raise significant concerns over environmental risks and animal welfare. The committee was set up by the National Academy of Sciences in response to a request from the US government. The government's regulatory body, the Food and Drug Administration, is currently debating whether it should approve the sale of GM meat and milk. Its decision is anticipated by the end of the year.

Data deficit

The committee admits that data is scarce, particularly on animals cloned from adult tissue, like Dolly the sheep - the technique known as somatic nuclear transfer. "Limited sample size, health and production data, and rapidly changing cloning protocols make it difficult to draw conclusions regarding the safety of milk, meat or other products from somatic cell cloned individuals," it says.

Some evidence comes from animals cloned by different, older techniques. Over two thousand Holstein cattle have been cloned since the 1980s in the USA, using methods called embryo splitting and blastomere nuclear transfer, BNT. These techniques have not been adopted widely, mainly because they do not improve yields. "Food products from BNT clones have been consumed by humans, with no apparent ill effects," the report says. But it urges the Food and Drug Administration to run tests on food made from cloned animals.

On genetically-engineered animals, the report is more equivocal. It says that with any genetically-modified organism, there is a large degree of uncertainty about how, when and where inserted genes will turn themselves on. New genes inserted into the DNA of GM animals will make proteins which are not normally present in the human diet, the report says. These could produce allergic reactions, or even be poisonous. The committee concludes that some GM animal products may pose what it calls a "moderate degree of concern" .

The report was welcomed by the Biotechnology Industry Organisation, BIO, a lobby group based in Washington DC. "It's very positive. They found no evidence of any danger from drinking milk or eating meat made from cloned or genetically-engineered animals," said spokeswoman Lisa Dry. "That's the same as we've found with genetically-engineered crops." According to BIO, there are currently about six companies in the world producing farm animals by cloning or genetic engineering.

Flying fish

The main issue with GM animals, the committee says, is the potential spread of inserted genes into the wild.

Fish, it says, present a particular problem. GM salmon which start life in farms may well escape into rivers and seas; and if they are bigger or fitter than normal salmon, their genes will spread through wild populations. Modified species might also be able to establish themselves in new areas of land or water. "A transgene that increases fitness or adaptations increases the risk of establishment and results in the highest level of concern," the report concludes.

The other concern the scientists raise is animal welfare. The report notes that some cloned animals, including cattle, have health problems around the time of birth, with some calves growing so big that they cannot be born naturally. This aspect of the report drew approval from Dr Sue Mayer of GeneWatch, an independent UK-based research group. "The committee has said that substantial differences can occur in genetically-engineered and cloned species," she said. "That means they need to be treated differently."

Coming revolution

So far, the genetic revolution has largely passed animal farming by; but the committee expects this to change. "Many of these recent advances have not yet left the experimental stage," they say, "But it is clear that that several, including transgenic finfish, which are soon likely to be commercialised, are likely to assume importance." The biotechnology industry sees GM animals as providing several benefits to consumers. "You could make animals with less fatty meat, or more nutritious milk," according to Lisa Dry. "Or they could be more resistant to diseases, which could make them safer for humans to eat."

But Sue Mayer disagrees. "We're deeply concerned that anyone is thinking of producing farm animals by such techniques," she said. "There are much better ways of solving the world's agricultural problems."

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US 'will rule cloned food safe'
2003/10/31
BBC

http://news.bbc.co.uk/go/pr/fr/-/2/hi/americas/3229941.stm

Milk and meat from cloned animals will not need special approval or labelling for sale in the United States, the country's food regulator is likely to decide. Preliminary Food and Drug Administration findings suggest that products from healthy cloned animals are safe. The FDA is releasing a summary of findings on Friday before a public meeting on the subject. Consumer groups have objected to the sale of such products. Cloning animals is currently too expensive to be practical for food production, but farmers could clone top-quality animals for breeding. Offspring of those clones could then enter the food supply without labelling, the findings imply. "If we consider [products from clones] materially the same as traditional foods, the role for the FDA would be minimal," the agency's Dr Stephen Sundlof told the New York Times.

'Indistinguishable'

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GM Cheese from Cow Clones
2003/1/27
BBC

http://news.bbc.co.uk/1/hi/sci/tech/2696725.stm

Cows are being modified to produce drugs and improved milk Scientists in New Zealand have created the world's first cow clones that produce special milk that can increase the speed and ease of cheese-making. The increases observed in our study represent large changes that would translate into substantial economic gains

NZ researchers

The researchers in Hamilton say their herd of nine transgenic cows make highly elevated levels of milk proteins - called casein - with improved processing properties and heat stability. Cows have previously been engineered to produce proteins for medical purposes, but this is the first time the milk itself has been genetically enhanced. The scientists hope the breakthrough will transform the cheese industry, and - if widened - the techniques could also be used to "tailor" milk for human consumption. But opponents of GM foods continue to doubt whether such products will be safe.

The researchers, led by Goetz Laible, engineered cells in the laboratory to overproduce casein proteins. The cells were then fused with cow eggs. The resulting embryos were transferred into recipient cows, and 11 transgenic calves were born. Nine were found to produce the enhanced milk. One protein, called kappa-casein, increases heat stability in the cheese-making process. The other, beta-casein, improves the process by reducing the clotting time of the rennet, which curdles the milk. It also increases the expulsion of whey, the watery part of milk which remains after the cheese has formed. The cows are now producing milk with 8-20% more beta-casein, and double the normal amount of kappa-casein. Reporting their findings in the journal Nature Biotechnology, the scientists said that controlling levels of the two proteins could offer big savings for cheese manufacturers. "When projected on to the production scale of the dairy industry, the increases observed in our study represent large changes that would translate into substantial economic gains,"

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Worm gene 'makes meat healthier'
2004/2/4
BBC

http://news.bbc.co.uk/2/hi/health/3459099.stm

Livestock could be genetically manipulated to produce "healthier" fats normally found in oily fish, say experts.

When a worm gene was placed into a mouse in the laboratory, omega-6 fatty acids were converted to the omega-3 version recommended by diet experts. Harvard University scientists say this could mean cows and sheep which produce meat and milk rich in healthy oils. Other scientists question whether breeding herds this way is justified. There are much easier ways to boost omega-3 levels in the diet and in produce, they say. Omega-3 fatty acids have emerged as a useful "super-food" - both appearing to protect the heart, and perhaps help brain development in children.

Oily fish

The best-known source is oily fish such as tuna and mackerel, although certain green vegetables and seeds also contain it. Mammals on a normal diet cannot produce Omega-3 in large concentrations. One way around this is to feed the animal on a diet extremely rich in omega-3s - and eggs produced from hens on this diet are already on sale in the UK.

'Fat' gene

The Harvard team, led by Dr Jing Kang, looked for a different way of producing a similar result. They found that they could take a gene called "fat-1" from the nematode worm - which, despite only being a fraction of a centimetre long, shares many genes with all other mammals, including humans. The effect of splicing this into the genetic makeup of mice was to produce an animal which could convert omega-6s into omega-3s. "Efforts have been made to incorporate n-3 (omega-3) fatty acids into the food supply because of their health benefits," the researchers wrote. "Production of n-3 fatty acids by the animals themselves would be a cost effective and sustainable way of meeting the increasing demand." However, not everyone agrees that this is a practical possibility. Dr Harry Griffin, from the Roslin Insitute - which pioneered the production of "transgenic" animals - said that few farmers, if any, would be willing to risk the premium they would have to pay to begin building a herd of these animals. He said: "It's a bit of a non-starter. The kind of people who are demanding omega-3 rich foods are probably those who would not eat anything taken from a transgenic animal. "There are other ways of achieving the same effect in livestock without the financial risk and difficulty."

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