AR-News: Scientists alter mice to produce omega-3 acids

[jim robertson]

"There are plenty of sources for omega-3 fatty acids in nature; they're in 
green vegetables, in legumes, in nuts and herbs and spices, and other oils 
like canola besides fish oils. It's just that people don't eat enough of 
them, because if they did, we wouldn't need genetic engineering to change 
our diets."

http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/02/05/MNG5I4PF421.DTL


Scientists alter mice to produce omega-3 acids
Process could someday be used in livestock, researchers say

David Perlman, Chronicle Science Editor
  Thursday, February 5, 2004


Crucial in everyone's diet are the specialized fats abundant in fish and 
fish oils but that don't exist in cattle, pigs, most poultry and many other 
common foods. The missing fats are known as omega-3 fatty acids, and 
nutritionists and heart specialists recommend that everyone get plenty of 
them.

Now four Harvard Medical School researchers report that they have taken the 
gene for the missing fatty acids from a lowly laboratory worm called C. 
elegans and have genetically engineered mice to produce the fats abundantly 
for generation after generation.

The same engineering trick also should endow animals that produce steaks, 
pork chops, omelets and other much-beloved foods with the same missing 
essential ingredient, the scientists suggest in a report being published 
today in the scientific journal Nature.

"Isn't that amazing," said Cynthia Kenyon, the famed molecular biologist at 
UCSF who has long studied the same worm's genes for its clues to human 
longevity. "It's so cool! Now you can just change the nutrition in your beef 
and make it even better for you."

The Harvard researchers -- Jing Kang, Jingdong Wang, Lin Wu and Zhao Kang -- 
proposed that their discovery could yield a new strategy for producing all 
kinds of foods that would be rich in omega-3s and that doing so would be "a 
cost-effective and sustainable" way of meeting the increasing demand for 
such foods without constantly exhorting hearty meat-eaters to make stringent 
dietary changes.

Commonly found in fish

The American Heart Association and cardiologists throughout the country have 
long urged people to consume more omega-3 fatty acids -- primarily in fish 
-- as a way of preventing heart disease.

Kang told the Associated Press that his team is trying to create a breed of 
chickens that would lay omega-3 eggs. The researchers also want to engineer 
the gene into farmed salmon as a way to make their conversion of fish food 
into omega-3s more efficient, according to the Washington Post.

The microscopic worm, formally named Caenorhabditis elegansis, is much 
beloved by genetics researchers because it can be so easily manipulated. It 
is also able to make its own omega-3 fatty acids from less healthful omega-6 
fatty acids, the type of fat that is prevalent in today's human diet.

The Harvard scientists took a gene from C. elegans and injected it into 
mouse embryos, which then were placed into surrogate mothers. The mice 
developed an unprecedented capacity to convert the omega-6 fatty acids in 
their diet into omega-3s, and this capacity was passed on to their 
offspring.

Scientific reservations

Kenyon said she had one reservation about the Harvard researchers' report: 
Although they followed four generations of the mice endowed with the omega-3 
gene and found that all the generations "appeared to be normal and healthy," 
Kenyon suggested that more study is needed to be certain that the mice had 
not undergone some unnoticed ill effects from the genetic manipulation -- 
changes that could also show up in meat and poultry treated the same way.

Another reservation was voiced by Marion Nestle, a former UCSF molecular 
biologist and nutritionist now at New York University, whose first comment 
on reading the Nature article was, "Well, it's a good thing we don't have to 
eat mice."

In a telephone interview Nestle, the author of the best-selling book "Food 
Politics," praised the technology used by the Harvard researchers as 
"awesome and beautiful science." But she added: "Yes, but to what end?"

"There are plenty of sources for omega-3 fatty acids in nature; they're in 
green vegetables, in legumes, in nuts and herbs and spices, and other oils 
like canola besides fish oils. It's just that people don't eat enough of 
them, because if they did, we wouldn't need genetic engineering to change 
our diets."

Any effort to breed cattle or other livestock containing the omega-3 acids 
through genetic engineering would face regulatory hurdles from the U.S. Food 
and Drug Administration and would be likely to meet the same consumer 
resistance that other genetically altered foods have encountered in the 
past.

The Associated Press and the Washington Post contributed to this 
report.E-mail David Perlman at dperlman at sfchronicle.com.





"I hold flesh-food to be unsuited to our species."
Mahatma Gandhi (1869-1948)

"Peace cannot be kept by force. It can only be achieved by understanding."
Albert Einstein





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