Shrink a grape, and you get a raisin. Shrink the grape genetic tree, and you get a looming disaster for oenophiles. That’s according to scientists who discovered that our cultivated wine grapes are more closely related than previously thought.
Sean Myles, a researcher at Stanford University, created a gene chip for common grape cultivars using genomes from the Department of Agriculture. In his study, published in the Proceedings of the National Academy of Sciences, he reveals that 75 percent of our 583 kinds of cultivated grapes are either parents, children, or siblings of each other.
“Previously people thought there were several different families of grape,” Dr. Myles said. “Now we’ve found that all those families are interconnected and in essence there’s just one large family.” [New York Times]
In this grape-world equivalent of the Jerry Springer Show, wines like merlot, pinot noir, and chardonnay are all interrelated in one big incestuous mash-up. And it’s the cultivators who are partly to blame.
The reason is obvious in retrospect. Vines can be propagated by breaking off a shoot and sticking it in the ground, or onto existing rootstock. The method gives uniform crops, and most growers have evidently used it for thousands of years…. The result is that cultivated grapes remain closely related to wild grapes, apart from a few improvements in berry size and sugar content, and a bunch of new colors favored by plant breeders. [New York Times]
Though the swine flu scare of 2009 may have bumped the avian variety of flu from of the popular imagination, biomedical researchers certainly haven’t forgotten the potential danger it poses. But researchers are constantly forced to play catch-up by following bird flu’s path through the avian population and trying to track its shifting genetics.
The way to finally get the jump on bird flu would be to create a weapon that works against the whole family of avian flu viruses, whatever their slight genetic quirks. And researchers led by Laurence Tiley say in Science this week that they might have found that kind of comprehensive trick: a genetic modification that seems to prevent flu from spreading in chickens.
It’s a decoy.
The birds carry a genetic tweak that diverts an enzyme crucial for transmitting the H5N1 strain. Although they die of the disease within days, the molecular decoy somehow impedes the virus from infecting others. [Nature]
Specifically, this genetic tweak allows the birds to create an RNA impostor. It matches up to the polymerase enzyme the flu virus would use to replicate its genetic material, so that enzyme is attracted to the decoy, which throws off viral replication. Though the modified chickens that were infected with avian flu died, the fact that they didn’t spread the virus is a potentially huge find—once avian flu enters a chicken population it typically spreads like wildfire.
In its first official report, the Presidential Commission for the Study of Bioethical Issues recommended that the budding field of synthetic biology remain unregulated.
In the report‘s (pdf) 18 recommendations, the commission does suggest that synthetic biologists should self-regulate their work and be required to take ethics training. It also recommends that the president’s office better coordinate government agencies to oversee the work. But it stopped short of calling for a halt on research that creates organisms not found in nature.
“The commission thinks it imprudent either to declare a moratorium on synthetic biology until all risks can be determined and mitigated, or to simply ‘let science rip,’ regardless of the likely risks,” the report says. “The Commission instead proposes a middle ground — an ongoing system of prudent vigilance that carefully monitors, identifies and mitigates potential and realized harms over time.” [The New York Times]
In an attempt to find a cure for type 1 diabetes, researchers are looking to an unlikely source: testicles. In a new study, researchers extracted stem cells drawn from human testes and reprogrammed them to produce insulin. When implanted into diabetic mice, the altered cells brought down the mice’s blood glucose levels, temporarily curing their diabetes.
In type 1 diabetes, the body’s immune system mistakenly destroys the pancreatic beta and alpha cells, which regulate blood glucose levels. Without the insulin created by their beta cells, diabetics experience high glucose levels that cause serious health problems.
Lead researcher G. Ian Gallicano and his colleagues took human spermatogonial stem cells–precursor cells that give rise to sperm–and reverted them to an embryonic state. Then the researchers coaxed them to develop into insulin-producing cells that resemble beta cells. Finally, they injected these pseudo-beta cells into the pancreases of mice with type 1 diabetes.
In a presentation on Sunday at the American Society for Cell Biology annual meeting, Gallicano said the graft was able to produce enough insulin to “cure” the mice of their diabetes for a week, though insulin levels were not high enough to treat humans this way.
In about a week and a half, officials at the Food and Drug Administration must complete their final deliberations over whether or not to approve a genetically modified salmon as the first GM animal in the world sold for human consumption.
It would seem they’re leaning toward “yes.”
Last Friday, while the country was preparing to go on vacation, the FDA released an analysis (pdf) of the transgenic salmon created by AquaBounty Technologies of Waltham, Massachusetts, declaring it safe to eat and safe for the environment.
The AquAdvantage Atlantic salmon contains a growth hormone gene from the Chinook salmon that is kept active all year round by a genetic on-switch from a different fish, the ocean pout. Normally, salmon produce growth hormone only in warm weather. So with the hormone produced year round, the AquAdvantage salmon grow faster [The New York Times].
“Faster” is an understatement. A normal Atlantic salmon requires about 30 months to grow large enough so that it can be sold at market. But a GM salmon with year-round growth hormone bulks up to market size in barely more than half that time—16 months or so.
Ecologists recently took to the highways of North Dakota on the hunt for genetically modified canola. Along 3,000 miles of interstate, state, and county roads, they found it: 86 percent of the 406 road-side plants they collected showed evidence of modification.
The scientists behind the discovery say this highlights a lack of proper monitoring and control of GM crops in the United States…. “The extent of the escape is unprecedented,” says Cynthia Sagers, an ecologist at the University of Arkansas in Fayetteville, who led the research team that found the canola. [Nature]
Though Sager does not believe that the modified canola will overtake North Dakota, she thinks the study is important for understanding how and to what extent a genetically modified crop can spread.
“We found the highest densities of plants near agricultural fields and along major freeways…. But we were also finding plants in the middle of nowhere–and there’s a lot of nowhere in North Dakota.” [BBC]
Geneticists have found a way to alter the sexual preference of lab mice. When they bred mice that had one gene deleted, the females declined male companions and preferred instead to court other females, according to a study published yesterday in BMC Genetics. But whether these results have any implications for humans is still far from clear.
Chankyu Park and his team at the Korea Advanced Institute of Science and Technology deleted the female’s fucose mutarotase gene and, as a result, changed the brain’s exposure to enzymes that control brain development.
The gene, fucose mutarotase (FucM), is responsible for the release of an enzyme by the same name, and seems to cause developmental changes in brain regions that control reproductive behaviors. The mice without the enzyme would refuse to let males mount them, and instead tried to copulate with other females. [AOL News]
Coming soon: Salmon that grow to full size in half the time?
With all sorts of genetically modified crops on the market and in the grocery store in the United States, genetically modified animals have been the next step waiting to happen. The New York Times reports that salmon could be the first up: This year the Food and Drug Administration will weigh approval of a GM salmon created by the company AquaBounty, which could be the first GM animal eaten by Americans.
It is an Atlantic salmon that contains a growth hormone gene from a Chinook salmon as well as a genetic on-switch from the ocean pout, a distant relative of the salmon. Normally, salmon do not make growth hormone in cold weather. But the pout’s on-switch keeps production of the hormone going year round. The result is salmon that can grow to market size in 16 to 18 months instead of three years, though the company says the modified salmon will not end up any bigger than a conventional fish [The New York Times].
When it comes to research on HIV and AIDS treatments, it can be hard to know when to celebrate a small advance–everyone wants to see progress, but so many experimental avenues that seemed promising have turned out to be dead ends. Still, a new study that tried a sophisticated form of gene therapy as an HIV treatment seems cause for cautious optimism. If it bears out under further testing, the technique could lead to a one-shot, long-lasting treatment that could replace the punishing regimen of daily medications.
Treating HIV currently comes down to managing the viral load with a mixture antiretroviral drugs. Researcher John Rossi and his colleagues tried to craft a more direct treatment by genetically modifying the HIV-infected patients’ own blood stem cells and increasing the cells’ ability to fight off the virus. The researchers weren’t able to truly combat the virus in this experiment–the patients’ viral loads remained the same–but their work moved beyond previous attempts in two ways: They successfully modified blood stem cells by giving them anti-HIV genes, and those cells survived for two years in patients.
Earlier clinical studies the group conducted with the same strategy made little headway, but now the researchers have overcome two key obstacles, says Rossi, a molecular geneticist. One is that they managed to stitch the anti-HIV genes into a high percentage of the appropriate stem cells. The other is that the cells lived for a long time. “If we could increase the number of modified cells by 10- or 100-fold, we might be able to stop the virus itself,” says Rossi. [ScienceNow]
Here in the United States, people are all atwitter about Craig Venter’s announcement last week of a new “synthetic cell,” and whether it constitutes creating life or simply a nifty new step in genetic engineering. Across the pond in the U.K., however, there are increasing rumblings of a more practical matter: Whether the patents that Venter is seeking to protect his work will bring a chill to genetic engineering research elsewhere.
Dr Venter’s [team] has applied for patents on the methods it used to create the new organism, nicknamed Synthia, by transferring a bacterial genome built from scratch into the shell of another bacterium. Synthia’s genetic code contains four DNA “watermarks”, including famous quotations and the names of the scientists behind the research, that could be used to detect cases of unauthorised copying [The Times].
Nobel winner John Sulston is the main man sounding the alarm (pdf); he argues that Venter is trying to obtain a “monopoly” on a range of genetic engineering techniques, which would prevent other researchers from freely experimenting with those methods. He’s also a familiar adversary to Venter. The two butted heads a decade ago when scientists were rushing to sequence the human genome.
Craig Venter led a private sector effort which was to have seen charges for access to the information. John Sulston was part of a government and charity-backed effort to make the genome freely available to all scientists [BBC News].