Almost 50 years after they won the Nobel Prize for defining the structure of DNA, Maurice Wilkins, James Watson, and Francis Crick are in the news again.

Nine boxes of “lost” correspondence (from the days before email!) between two competing groups of researchers have been unearthed. The letters, between Wilkins and Rosalind Franklin of King’s College and Watson and Crick at Cambridge University, provide insight into the researchers’ mindsets while they were making these historic, game-changing discoveries.

“The [letters] give us much more flavor and examples illuminating the characters and the relations between them,” said study researcher Alexander Gann, editorial director at Cold Spring Harbor Laboratory Press in New York. “They’re consistent with what we already believed, but they add important details.” [MSNBC.com]

Gann and Jan Witkowski published a commentary on the new material in the September 30 issue of Nature. The letters highlight the different mentalities between the two groups as they approached the project: an attitude of spirited excitement on the side of the Cambridge clan, and an air of anxiety from Wilkins.

(more…)

It’s the most delicious genetic breakthrough yet. A consortium led by Mars Inc., the company behind such treats as M&Ms and Snickers, has announced the rough draft of the cacao tree’s genome, and researchers say the information could lead to improvements in the chocolate supply.

While the scientists are just beginning to analyze the genome, understanding the tree’s innermost workings could lead to breeding programs for drought- or disease-resistant varieties, or even for trees that produce tastier or healthier cocoa. The consortium has put the data online at the Cacao Genome Database for use by any and all.

The tree, known officially as Theobroma cacao (meaning “food of the gods”), contains about 420 million DNA units, represented by the letters A, C, G and T. That is fairly small for a plant. The human genome has about three billion units. [New York Times]

(more…)

The genetics behind near-sightedness are coming into focus.

In studies (1, 2) in Nature Genetics that looked at more than 4,000 people, scientists report that variations in a gene called RASGRF1 are partly responsible for whether or not a person develops myopia.

“It is not quite the end of glasses yet but clearly the hope is that we will be able to block the genetic pathways that causes shortsightedness,” said Dr Christopher Hammond at King’s College London, an eye surgeon who led the British research. [The Telegraph]

(more…)

What does it take to be a long-living queen? Change your gene expression, say researchers who analyzed both worker ant and queen ant genes in two ant species–making the humble bug the second social insect (after the bee) to get sequenced.

Their results appear today in Science and suggest that epigenetic changes–molecular switches that alter gene expression–may mean the difference between the queen’s long life, and the workers’ short one. Epigenetic changes don’t actually modify the underlying genetic code, instead they’re carried out by mechanisms that act like on and off switches for genes. That could explain how a queen and worker ant can have the same genetic blueprints but very different lives.

“Ants are extremely social creatures and their ability to survive depends on their community in a very similar way to humans,” says [co-author Danny] Reinberg, who is also a member of the NYU Cancer Institute. “Whether they are workers, soldiers or queens, ants seem to be a perfect fit to study whether epigenetics influences behavior and aging.” [Arizona State University]

(more…)

The problem: Scientists want to study our circadian rhythms, our bodies’ internal clocks, and they can do so on the genetic level by examining how gene expression changes throughout the day. But ordinarily that would require sampling a person’s blood or skin multiple times a day, an ordeal few of us would want to endure.

The solution: hair.

Makoto Akashi’s team reports today in the Proceedings of the National Academy of Sciences that hairs, be they from the beard or head, contain the telltale signature of RNA activity that shows when we humans are at our peak activity level for the day.

(more…)

Is it medicine, or is it not?

In May, the University of California, Berkeley unveiled its “Bring Your Genes To Cal” program. The idea was, Berkeley’s 5,500 or so incoming freshman would have the option to have their DNA tested for three particular characteristics: Their metabolism of folate, tolerance of lactose, and metabolism of alcohol. Though the program was limited, it raised privacy hackles. And now the State of California has ruled: This is a medical test, and Cal can’t do it unless it’s in a clinical setting.

Mark Schlissel, UC Berkeley’s dean of biological sciences and an architect of the DNA program, said he disagreed with the state Department of Public Health’s ruling that the genetic testing required advance approval from physicians and should be done only by specially-licensed clinical labs, not by university technicians. The campus could not find labs willing to do the work and probably could not afford it anyway, Schlissel said. He also contended that the project deserved an exemption from those rules because it was an educational exercise [Los Angeles Times].

(more…)

In January, we discussed a biotech first–a transformation from skin cell to brain cell, without reverting to a more mutable stem cell in between. Today a paper in the journal Cell describes a similar direct transformation in mice, from a type of structural cell called a fibroblast to heart cells. If one day scientists can entice human cells to make a similar “direct conversion,” the researchers believe this metamorphosis may prove one way to fix heart damage that’s irreparable under the current state of medicine.

The study’s authors at the Gladstone Institute of Cardiovascular Disease at the University of California, San Francisco, once attempted to use stem cells for heart repair with little success, Nature News reports. Though the stem cells quickly turned into the beating variety, called cardiomyocytes, they remained feeble, never transforming into the strongly beating muscle cells of a healthy heart.

“I don’t know that this [direct conversion] will entirely replace stem cells,” says Deepak Srivastava [lead author on the study]… “But it will offer another strategy that might remove some of the concerns of using stem cells.” [Nature News]

(more…)

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.

Sager announced these results at this week’s Ecological Society of America meeting.

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]

(more…)

One might think that identical-twin bacteria—clones of each other—would grow up and live very similarly. But a study published today in Science that examined individual bacterial cells in detail found that genetically identical E. Coli cells actually seem to express their genes quite differently, simply because of the random accidents of how their molecular machinery happens to operate.

“The paper is quite rich,” said Sanjay Tyagi, a molecular biologist at New Jersey Medical School who was not involved in the research [but published a perspectives piece on it]. “People think that if an organism has a particular genotype, it determines its phenotype [observable characteristics]–that there’s a one-to-one relationship,” said Tyagi. “But as it turns out, [differences in gene expression] can arise just from chance.” [The Scientist]

(more…)

In a medical sense, you’d be wise to steer clear of filoviruses, a group that includes the deadly Ebola, and bornaviruses, which cause neurological diseases. But in a genetic sense, it may not be possible to avoid them. A new study in PLoS pathogens shows that bits and pieces of these viruses have been floating around in the human genome, as well as those of other mammals and vertebrates, for millions of years.

It’s not that having genetic material left behind by viruses is odd—previous research had shown that viruses account for 8 percent of the human genome. But scientists thought most of that material came from retroviruses, which use their host’s DNA to replicate and leave some of their genetic material behind. What’s weird about this is that filoviruses and bornaviruses are not retroviruses—they’re RNA viruses, which don’t use the host to reproduce in the same way.

(more…)

The summer of our government’s discontent (with personal genetics tests) continues. Yesterday an investigator with the Government Accountability Office reported back to Congress on its undercover investigation of the tests on the market, saying that testing the DNA of GAO staffers returned frequently contradictory and confusing answers.

“Consumers need to know that today, genetic testing for certain diseases appears to be more of an art than a science,” said GAO investigator Gregory Kutz [CBS News].

Here at 80beats, we’ve gone over some of the potential problems with these tests. DISCOVER blogger Ed Yong covers them in great detail in a post he wrote this week after getting his genes tested by 23andMe, including the dearth of data appropriate for interpreting results if you’re of Asian rather than European descent, and deciding whether to peek into the data that says whether you have a much higher than average risk for Parkinson’s disease.

(more…)

Andrew Crawford and his colleagues discovered 11 new species of amphibians in Panama. But they wish it hadn’t happened this way.

The team just completed a long-term study of amphibians in Panama’s Omar Torrijos National Park, published in the Proceedings of the National Academy of Sciences, showing the startling disappearance of species there. Co-author Karen Lips began the study back before the disease chytridiomycosis, which is caused by a fungus called Batrachochytrium dendrobatidis and has devastated amphibian populations, reached that place and began to afflict its inhabitants.

The pre-decline surveys identified 63 species of amphibians within just a 1.5-square-mile (4-square-kilometer) area. After 2004, 25 of those species had disappeared from the site. As of 2008, none had reappeared. An additional nine species saw an 85 percent to 99 percent decline in their abundance [MSNBC].

(more…)

Identical twins don’t share everything. The mix of viruses in a person’s gut, a new study says, is unique to each of us, even if we share nearly all our DNA with another person. That is, at least according to our poop.

This year scientists have been working to decode the genetics of the beneficial microbes that live inside us, like the bacteria that help us digest food. But those trillions of bacteria have partners of their own—beneficial viruses. Jeffrey Gordon and colleagues wanted to see what those viruses were like, and how they differed from person to person. To do it, they studied fecal samples that came from four sets of identical twins, as well as their mothers.

Each identical twin had virus populations that didn’t resemble those of their sibling—or anybody else, for that matter.

Remarkably, more than 80 percent of the viruses in the stool samples had not been previously discovered. “The novelty of the viruses was immediately apparent,” Gordon said. The intestinal viromes of identical twins were about as different as the viromes of unrelated individuals [MSNBC].

(more…)

Some like it hot. The bacteria Francisella tularensis is among them. It likes to live at the temperatures present inside human bodies, and give us the disease tularaemia. But Barry Duplantis figured out a way to make the body an unattractive destination for the bacteria: He injected it with the genes of a cold-lover.

In a study in this week’s Proceedings of the National Academy of Sciences, Duplantis brought in Colwellia psycherythraea, a bacteria that can survive in the icy temperatures of the Arctic, but would die at a temperature like the nearly 100 degrees inside our bodies. By transferring genes responsible for that temperature sensitivity into F. tularensis, he created versions of that bacteria with lower heat tolerances.

When he injected these microbes into mice, they couldn’t migrate to warm areas like the lungs and do damage. Plus, the presence of the incapacitated bacteria acted as a sort of vaccine, putting the animals’ immune systems at the ready. When the researchers later gave the mice large exposures to unaltered F. tularensis, they didn’t get as sick as control mice.

For plenty more on this study, check out Ed Yong’s post at Not Exactly Rocket Science.

Check out DISCOVER on Facebook.

Related Content:
Not Exactly Rocket Science: Genes from Arctic Bacteria Used To Create New Vaccines
80beats: In Mice, Breast Cancer “Vaccine” Trains the Body To Fight Cancerous Cells
80beats: Non-Lethal Antibiotics Could Fight Superbugs

Image: Richard Finkelstein

Los Angeles police say that Lonnie Franklin Jr. may be the “grim sleeper” serial killer they have sought for more than 20 years. And if indeed they do have their man, they have his son to thank—for getting arrested himself.

Franklin is one of the first major suspects nabbed by police using familial DNA. With this controversial method, investigators look for partial matches between DNA left at a crime scene and DNA profiles that are stored in police databases; a partial match may indicate that the person is related to the target individual sought by the cops.

The trail began to heat up when the DNA of Franklin’s son was entered in a state database after he was convicted in a weapons case, authorities said. The son’s DNA was similar to genetic material found on the victims, and authorities soon began following around Franklin to get his DNA and see if he was the suspected killer [AP].

The cops posed as waiters at a restaurant where the elder Franklin ate, which is how they obtained a complete DNA sample from him–they grabbed a plate and napkin he tossed after eating a slice of pizza. The investigators say that when they found the match to the samples in their evidence, it eased 25 years of frustration at not being able to track him down.

(more…)