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Entries in DNA (19)

Tuesday
Dec042012

AquaBounty Hoping to Serve DNA-Altered Salmon on US Plates

Jupiterimages/Thinkstock(NEW YORK) -- Deep in the rainforests of Panama, in a secret location behind padlocked gates, barbed-wire fences and over a rickety wooden bridge, grows what could be the most debated food product of our time.

It may look like the 1993 hit movie Jurassic Park, but at this real-life freshwater farm scientists are altering the genes not of dinosaurs, but of fish.

They are growing a new DNA-altered saltwater fish in the mountains, far from the sea -- a salmon that could be the first genetically altered animal protein approved for the world to eat. If it is approved, this would be a landmark change for human food.

But it is one critics call "Frankenfish."

"The idea of changing an animal form, I think, is really creepy," said Gary Hirshberg, founder of Stonyfield Farm, an organic dairy farm. "When you move the DNA from a species into another species ... you create a new lifeform that's so new and so unique that you can get a patent for it."

 

And until now, AquaBounty, the multinational biotech company that for 20 years has been developing this giant fish, has kept it under close wraps.

The press has never been invited to its Prince Edward Island laboratory on the Canadian maritime coast, and its fish farm location in Panama has been kept secret out of fear of sabotage.

The Food and Drug Administration has seen it, but few from the outside. In fact, the last public tour of any kind was four years ago.

ABC News was given exclusive access to see the facilities up close and an opportunity to taste this mysterious fish that FDA scientists say "is as safe as food from conventional Atlantic salmon," although have yet to officially approve it for public sale.

Ron Stotish, the president and CEO of AquaBounty Technologies, the company that created and hopes to market the eggs of this salmon to independent fish farms around the world, told ABC News it has employed bio-security measures, creating a "Fort Knox for fish," to ensure safety for the fish and prevent cross-contamination with the wild.

Entry to both facilities begins with body suits and iodine baths for shoes, which serves to keep the fish safe from germs.

Inside these protected tanks, America gets the first up-close look at the final product, the fish that has the food police up in arms.

"These are very healthy, beautiful Atlantic salmon," Stotish said.

With one big difference -- the growth rate of a regular salmon compared to that of an AquaBounty genetically modified fish.

While the AquaBounty fish do not grow to a size larger than normal salmon, they get to full size much faster, cutting costs for producers.

A normal-size 1-year-old Atlantic salmon averages 10 inches long, while the genetically modified fish at the same age is more than two times larger, coming in at 24 inches.

Salmon is the second-most popular seafood in America. According to the National Oceanic and Atmospheric Administration, the average size of an Atlantic salmon is 28 inches to 30 inches and 8 pounds to 12 pounds after two years at sea.

How do they accomplish the accelerated growth?

"They differ by a single gene," Stotish said.

But, it's that single gene change that makes the DNA-altered salmon grow much faster than a normal Atlantic salmon, because it's really three fish in one.

AquaBounty scientists have taken a growth gene from the Chinook salmon and inserted it into the DNA of the Atlantic salmon because Chinooks grow fast from birth, while Atlantics do not.

"Salmon in their first two years of life grow very slowly," Stotish said.

Then there is one more genetic alteration -- a growth switch from a sea eel also is inserted in the Atlantic salmon DNA because natural salmon normally only grow in summer. The eel grows all year round.

John Buchanan, the director of research and development for AquaBounty, has been working on the salmon for two decades and explained that the change allows the fish to start growing from birth.

"You get to market size at least 12 months before any other type of salmon out there," Buchanan said.

AquaBounty says the fish are ready for market and it now wants the FDA to give final approval of what it calls the AquaAdvantage salmon for American dinner plates.

Already 80 percent of U.S. corn, soybeans and sugar beets are genetically altered, but until now ... never meat.

"It opens up a whole other section of the grocery store, to a technology which we think is still not fully understood," said Patty Lovera, the assistant director of consumer rights group Food & Water Watch.

Sensitive to criticism that these fish could escape into the wild and wipe out natural salmon, AquaBounty is anxious to show what it says are 16 redundant safety nets to keep their fish inside.

"We've been operating this facility for more than 20 years and we've never lost a single fish," Stotish said.

Another safeguard, Stotish explains, is that these super-fish are sterile.

"These animals can't transmit their genetic information to generations. They're incapable of breeding and that's perhaps the most important part," he said.

That assures nothing can go wrong with this fish altered by science to grow and get to market faster, he said.

"This fish is identical to traditional salmon in every measurable way," Stotish said.

Michael Hansen, senior staff scientist for Consumers Union, said he thinks science has gone too far though.

"I wouldn't want to eat this fish, unless it's gone through a proper approval process," he said.

There is no proven link between genetically altered food and health problems, but critics are skeptical about AquaBounty studies and complain government scientists have not done enough independent work, and ignore the unknown.

They worry, but have no proof that this new fish will increase allergies, and they theorize its altered hormone system could somehow cause cancer. The FDA's review of company data found those concerns unfounded.

But Hansen remained skeptical.

"That kind of science wouldn't make it past a high school science fair," he said.

When ABC News asked AquaBounty whether eating its fish should be cause for concern or fear, the company argued that DNA is in everything a person eats.

"You eat DNA every time you swallow," Stotish said. "You consume DNA with every food that you eat."

But when pressed by ABC News about the difference in the fish's altered DNA, Stotish responded that the alteration comes from a nearly identical fish and if eaten will make consumers healthier.

"The gene that's responsible for the rapid growth comes from the Chinook salmon, a Pacific salmon, that protein is essentially identical to the same protein that's produced by Atlantic salmon," Stotish said. "You have healthier levels of Omega 3-fatty acids, you will be consuming a very lean source of protein."

ABC News was offered an opportunity to taste the DNA-altered salmon to see whether there is a difference in flavor or texture. None was noticed.

Currently, there are almost no commercial wild Atlantic salmon left in the world and virtually everything consumers purchase at the store is raised in ocean pens at salmon farms as far away as Chile or Norway.

AquaBounty argues its freshwater fish will be raised closer to big cities and be fresher and environmentally friendlier because there will be no need to ship them from overseas.

"Man has been altering the nature of animals since man walked upright and began domesticating animals," Stotish said. "The beef that we consume, the pork we consume today don't resemble their early ancestors at all."

If FDA approval doesn't come soon, AquaBounty says its 20-year investment will go belly-up -- which the company says will be a setback for its investors and for science.

Copyright 2012 ABC News Radio

Monday
Apr022012

DNA Testing Not So Potent for Prevention, Study Says

Comstock/Thinkstock(BALTIMORE) -- When scientists developed the ability to catalog a person’s genes, many hailed whole genome sequencing as modern medicine’s best tool to predict and prevent serious diseases, such as cancer. But according to a new study, whole genome sequencing is not the magic bullet for prevention -- at least not yet.

A team of researchers from Johns Hopkins Kimmel Cancer Center found that the test fails to provide solid predictive evidence for a large portion of people. The findings were published online Monday in the journal Science Translational Medicine.

“From a public health perspective, basically, it’s a reality check. It tells us what will we be able to do, and what won’t we be able to do with whole genome sequencing,” said Dr. Bert Vogelstein, co-director of the Hopkins’ Ludwig Center for Cancer Biology Research in Baltimore, and an author of the study.

The researchers analyzed data from thousands of identical twins, noting how many of them had developed any of 24 different diseases, including cancer and autoimmune, cardiovascular, genitourinary, neurological and obesity-related disorders.

Vogelstein said data from identical twins, who share the same genome, give scientists an opportunity to study the genetic components of disease. If the genome was the determining factor for common diseases, then the number of twins who have a certain disease that their twin also has could show how well whole genome sequencing could predict an individual’s disease risk, he said.

Using what they knew about how many of the twins developed certain disorders, the researchers created a mathematical model to calculate the capacity of whole genome sequencing to predict the risk of each disease.   

They found that the majority of people would receive negative results for 23 of the 24 diseases, even though the risk of developing 19 of them in people who tested negative would still be 50 to 80 percent of the risk in the general population. The researchers reported that the best-case scenario would mean that 90 percent of people tested would be alerted to a clinically significant predisposition to at least one disease.

Vogelstein told ABC News that the study found that whole genome sequencing is not a perfect predictor of a person’s future health.

“In some cases people may find it useful, but others will decide that it’s less useful,” Vogelstein said. “All we’re trying to do is provide the limits so people will know what they’re paying for and what the capacity is of these tests.”

A number of private labs provide whole genome sequencing services for about $3,000 per genome, but prices are dropping as the technology improves.

Dr. Ronald Crystal, chairman of genetic medicine at Weill Cornell Medical College in New York City, said the tests are still a valuable way to test for the risk of certain diseases that have definite genetic links, such as Alzheimer’s disease or type 1 diabetes. But for many diseases, for example cancer, which are shaped by a symphony of genetic, environmental and behavioral risk factors, scientists still need much more research before learning what genetic results mean for a specific individual’s risk.

“In terms of disease prevention, what we tell patients now still holds:  Don’t smoke, don’t do drugs, don’t be obese, eat sensibly and exercise,” Crystal said.

Copyright 2012 ABC News Radio

Monday
Oct312011

Study Reassuring for Women Whose Families Have BRCA Mutation

Photodisc/Thinkstock(STANFORD, Calif.) -- Women whose female relatives have a notorious breast cancer gene but who do not have the gene themselves may be able to breathe a slight sigh of relief.

New research that refutes previous findings suggests that women who do not carry their family's BRCA genetic mutation are at no higher risk of getting breast cancer than relatives of people with other types of breast cancer.

The findings of the study, which examined more than 3,000 families, countered a 2007 study that suggested women who tested negative for the BRCA mutation -- but had a first-degree family member who carried the gene -- had a two- to five-fold increased risk of developing breast cancer.

These women still are at greater risk for the disease than women who do not have a family history of breast cancer. But the study's findings, published in the Journal of Clinical Oncology, found that women are not at an even greater risk solely because of their BRCA family history.

"This is a reassuring result," said Dr. Allison Kurian, first author of the study and assistant professor of oncology at Stanford University Medical Center. "We found women who tested negative for BRCA mutation do not have a greatly elevated risk of breast cancer."

"This isn't to say that women may not have other reasons for increased risk due to other factors," said Kurian. "Cases should be managed in an individual way."

Breast cancer is the most common cancer among women in the United States. More than one in eight women will develop the disease in their lifetimes, according to Breastcancer.org. While only about 10 percent of breast cancer diagnoses stem from the genetic mutation, women with the BRCA genetic mutation have a 45- to 65-percent chance of getting breast cancer, and those increased odds often result in more frequent mammograms and preventive mastectomies.

The BRCA-1 and BRCA-2 genetic mutations were first discovered in 1994. At the time, researchers believed that relatives of a person who carried the BRCA gene were not at greater risk than any other family member of a person with other kinds of breast cancer. The 2007 study countered that initial belief, but these newly published results bolster the original understanding of the genetic mutation.

The study compared noncarriers with a family BRCA history with noncarriers who have other types of breast cancer in their families.

Kurian said the 2007 study may have found conflicting results because researchers compared the BRCA family members with the general population.

Cancer specialists say patients can now feel some relief and return to normal screening patterns. It's important to educate high-risk patients on appropriate prevention and treatment options, they said.

Copyright 2011 ABC News Radio

Friday
Oct282011

Possible Genetic Marker for Depression Risk Identified

Jupiterimages/Thinkstock(SAN ANTONIO) -- New research has identified a genetic marker that may pinpoint people at high risk for major depression, which scientists say could lead to earlier treatment.

Using blood samples from more than 1,100 Mexican Americans from 40 extended families, researchers at the Texas Biomedical Research Institute in San Antonio and Yale University found an association between a gene called RNF123, which plays a role in the growth of nerve cells, and the risk of major depression. They used a new method that analyzed more than 11,000 different genetic variables.

RNF123 can easily be measured in a person’s blood, which may make it possible to identify people at risk for this debilitating disorder.

“We might be able to know in advance that a person will be less able to respond to the normal challenges that come about in life,” John Blangero, a co-author and director of Texas Biomedical’s AT&T Genomics Computing Center, said in a press release.

While they don’t know exactly how RNF123 may lead to depression, the authors believe it could influence the structure of certain parts of the brain.

Scientists not involved in the study say this is a very promising new approach to zeroing in on how genetic factors manifest themselves in certain disorders.

“There have been a few markers shown to have some relationship to depression, but it’s been really hard to identify specific ones related to major depression,” said Adam Naj of the John P. Hussman Institute for Human Genomics at the University of Miami’s Miller School of Medicine.

Conventional methods of evaluating genetic risk involve comparing the genetic makeup of people who have a certain medical condition to people who don’t, and then going back to try to figure out what effects they have on the body. This type of analysis, Naj said, allows for more detailed identification of genetic factors.

“With this approach, we can try to figure out what the genetic variations may do to features closely related to the disorder,” he said.

Naj also said this method of analyzing heritable factors has been used in research on other conditions, such as cardiovascular disease and diabetes.

Copyright 2011 ABC News Radio

Wednesday
Oct122011

Decoding the Black Plague

Comstock/Thinkstock(HAMILTON, Ontario) -- The Black Death that killed 50 million Europeans six centuries ago is the ancestor of “all the modern plagues we have today worldwide,” say the scientists who decoded its entire genetic structure from the teeth of long-dead Londoners.

“Every outbreak across the globe today stems from a descendant of the medieval plague,” said Hendrik Poinar, a geneticist from Canada’s McMaster University, and leader of the international team whose accomplishment includes being the first to reconstruct the genome of any ancient pathogen. The findings should allow scientists to determine how the notorious bubonic plague, which ravaged Europe between 1348 and 1351, evolved over the centuries, he said. That plague is the genetic ancestor of the plague that claims an estimated 2,000 lives every year.

The research team, headed by scientists from McMaster and the University of Tubingen in Germany, analyzed DNA in a strain of the Yersinia pestis bacterium retrieved from skeletal remains of five people who perished in 1349-50 and were buried in London’s East Smithfield “plague pits,” beneath where the Royal Mint stands today. The scientists extracted the DNA from the victims’ dental pulp.

Poinar said there had been few changes in the genome of the bug since it ravaged Europe. The research team could not tell if those changes contributed to the plague’s increasing disease-causing power. “The next step is to determine why this was so deadly,” Poinar said.

Genetic information drawn from the 14th century victims allowed the scientists to determine that the plague strain that proved one of mankind’s deadliest biological foes dated to sometime between the 12th and 13th centuries. That helped differentiate it from a sixth century Justinian plague, which moved through the Eastern Roman Empire, wiping out an estimated 100 million people.

The findings, published Wednesday in the online issue of the scientific journal Nature, open the door to understanding more about the history and origin of other infectious diseases, said Johannes Krause of the University of Tubingen, another lead study author. “This will provide us with direct insights into the evolution of human pathogens and historical pandemics.”

Copyright 2011 ABC News Radio

Tuesday
Sep062011

Sperm Donor ‘Super Dads’: The Risks of One Donor 'Fathering' Dozens

Robert Houser/Getty Images(NEW YORK) -- A woman who conceives a child through a sperm donor has to make her peace with a number of unknowns -- what the donor looks like, what personality quirks he might have or whether big noses run in his family.  But one thing she probably didn’t bargain for was the possibility that her child could have more than 100 half-siblings out there, likely living in the same state, or even in the same city or neighborhood.

This was the outcome for Cynthia Dailey, who, through a little online research and networking, learned that her son had 149 half-siblings, all fathered by the same donor.  Her story, reported by The New York Times this week, highlights a long-held concern among sperm bank critics: Shouldn’t we limit the number of offspring a single donor can sire?

As it stands now, there are no rules in place to monitor or limit how many times a single donor’s sperm can be sold -- a situation that has allowed some sperm banks to oversell their donors, producing clans of more than 100 half-siblings.

ABC News covered this phenomenon last August, when we spoke to Chase Kimball, a sperm donor who, like the one Dailey used, likely fathered “hundreds of children” in the 1970s and 1980s.

It got the point where the clinic told him, “You’ve got too many kids locally, and we can only use your sperm if someone orders it from out of state.”

Having this many offspring is certainly not what Kimball and other sperm donors bargained for, and critics of sperm banks worry that allowing a single donor to father so many children will have negative ramifications for these children.

Because most sperm donations are doled out to women living in the same general area, some critics argue that unintentional incest could occur.

Even more threatening may be what these “superdads” do to the gene pool, say some critics.  Sperm donors are tested for inherited diseases to varying degrees -- what they’re tested for differs from state to state -- but donors may still be passing along genetic abnormalities and diseases.

Copyright 2011 ABC News Radio

Tuesday
Aug092011

Genetics Tied to Intelligence  

Comstock/Thinkstock(NEW YORK) -- Nearly 50 percent of human intelligence can be explained by genetics, according to a new study.

In a genome-wide analysis of 3,511 unrelated adults, researchers scanned data on nearly 550,000 single nucleotide polymorphisms (SNPs) and found that small contributions from a variety of genes may explain intelligence.

HealthDay reports that the study, that appears in the Aug. 12 issue of Molecular Psychiatry, tested participants for two types of intelligence: knowledge and problem solving.

Researchers analyzed SNPs -- one-letter changes in a DNA sequence that account for 90 percent of human genetic variations, according to the Human Genome Project.

Scientists found that 40 to 50 percent of gene variations relating to knowledge and problem solving came from genetic differences

While the research indicates genes influence intelligence, researchers caution using genetics solely to determine intellect, as both nature and nurture play a role.

Research was conducted by Ian Deary, Ph.D., MBChB, professor of differential psychology at University of Edinburgh in Edinburgh, Scotland, and by Peter Visscher, Ph.D., a professor of statistical genetics at Queensland’s Institute of Medical Research in Brisbane, Australia.

Copyright 2011 ABC News Radio

Monday
Aug012011

Court Rules in Favor of Patents on Human Genes

Comstock/Thinkstock(NEW YORK) -- A federal appeals court has ruled in favor of companies patenting isolated human genes.

The U.S. Court of Appeals overturned a lower court decision that ruled Myriad Genetics could not patent human genes in an effort to help predict if women have an increased risk of getting breast and ovarian cancer, according to The New York Times.

In the court's ruling, it cited the difference between DNA isolated from the body and DNA that lives inside the body's chromosomes in determining a company's right to patent genes. The court's decision rested on the notion that DNA isolated from the body was "markedly different" from the genes inside chromosomes because the isolated DNA is not a product of nature.

The 2-to-1 decision also ruled against Myriad for its gene mutation screening methods because it only involved “patent-ineligible abstract mental steps.”

Copyright 2011 ABC News Radio

Tuesday
Jul192011

Stress During Pregnancy May Permanently Alter a Child's DNA, Say Researchers

Comstock/Thinkstock(KONSTANZ, Germany) -- Stress experienced by a pregnant woman can have long-lasting effects on the psychological health of her child -- an effect well documented through observational studies showing that such children have an increased risk of behavioral and other problems later in life.  

Now German researchers at the University of Konstanz have found that, for the first time, children of women experiencing intimate partner violence during pregnancy have a modification on their DNA that could alter the way their stress-related genes function, possibly contributing to their increased risk of behavioral and mental problems. 

Perhaps what is most interesting about this finding is that these DNA modifications were detected 10-19 years after birth!  

This data provides solid human evidence that environmental events experienced during early development have the power to change how genes function for the rest of the person’s life.

This study's findings were published in the journal Translational Psychiatry.

Copyright 2011 ABC News Radio

Sunday
Jun122011

Study Finds DNA Mutation Rate Varies for Individuals

Comstock/Thinkstock(CAMBRIDGE, England) -- In the popular comic book and movie series X-Men, the characters are known to have superpowers through mutations in their DNA. In actuality, humans are born with genetic mutations and a study conducted by the Wellcome Trust Sanger Institute of Cambridge, United Kingdom took a closer look at such mutations and how these mutations were passed on from parents to children.

In the study, researchers screened the entire genetic sequence of 6 individuals, two sets of parents with one child. The findings of the study, which were published in Nature Genetics, revealed that the children received about 60 DNA mutations from their parents, but that the large majority of new mutations arose spontaneously in the children. 

An interesting observation, however, came from analyzing the mutations that came from the parents.  Since the mid-1900s, it’s been thought that more mutations arise in sperm than in eggs because the speed at which sperm are created makes them more vulnerable to genetic mutations. This hypothesis was a little shaken by the finding that in one of the families, the father's DNA contributed 92 percent while in the other only for 36 percent of the mutations the child inherited from the parents. 

The study has found that the mutation rate varies from individual to individual, or that some people have mechanisms that reduce the likelihood of mutations.

Copyright 2011 ABC News Radio







ABC News Radio