Fresh insights into genetic variations that are opening the way to personalized medical treatments have won the journal Science’s recognition as the top scientific breakthrough of 2007.
Science's editors annually assess the past year's top research and rank the most significant breakthroughs in their year-end issue. Last year's top finding was the solution of the Poincare conjecture, a complex 100-year-old mathematical puzzle. Other breakthroughs from past years have focused on the evidence for ancient life on Mars, the detection of mysterious dark energy and revelations about human origins.
"For years, we've been hearing about how similar people are to one another and even to other apes," Robert Coontz, who managed the selection process as Science's deputy news editor for the physical sciences, said in Thursday's announcement of the top breakthroughs. "In 2007, advances on several fronts drove home for the first time how much DNA differs from person to person, too. It's a huge conceptual leap that will affect everything from how doctors treat diseases to how we see ourselvs and protect our privacy."
This year, an international scientific consortium released a detailed analysis of genetic differences in a geographic populations. Meanwhile, other studies have linked variants in more than 50 genes to increased risk for a dozen diseases, ranging from hypertension to autism. The findings raise hope for developing custom-made cures — but also raise questions about the potential for gene-based discrimination.
Also this year, scientists released the first complete genomes of publicly identified individuals, including that of J. Craig Venter, who helped spearhead the initial decoding of the human genome seven years ago. The original Human Genome Project sketched out the geography of our genes in general terms — but since then, scientists have found a surprising degree of difference between individual genetic codes.
"It totally changes our view of what’s out there, in the sense that we look like we're 1 to 2 percent different from each other instead of 0.1 percent," Venter told msnbc.com. "That’s a huge change."
The genome is certain to get more personal in the future: Genetic tests for family markers have been available for years at a price as low as $100. Some companies — such as 23andMe, Navigenetics and deCODE Genetics — offer more extensive gene-marker tests for $1,000 to $2,500. And Science notes that a new company called Knome is offering whole-genome sequencing for $350,000.
"The potential to discover what contributes to red hair, freckles, pudginess or a love of chocolate — let alone quantifying one's genetic risk for cancer, asthma or diabetes — is both exhilarating and terrifying," Science's editors write.
Cell reprogramming came in as the first runner-up in Science's list. In June, Japanese and American teams reported that they had chemically reprogrammed mouse skin cells to act like embryonic stem cells, taking on the ability to produce virtually every type of body cell — including eggs and sperm.
Then, in November, two teams said they performed the same trick with human skin cells.
"Like the main breakthrough, reprogramming cells could open new avenues of biomedical research once scientists clear a few more hurdles," Coontz said. "It was a strong contender for our main breakthrough, but we gave the nod to human genetic variation because it's so fast-moving and so sweeping."
Eight other research areas round out Science's top 10:
- The source of cosmic rays: Scientists using the Pierre Auger Observatory in Argentina reported that the highest-energy cosmic rays appear to emanate from enormous black holes in the middle of distant galaxies.
- A key molecular relay: Four research papers detailed the structure of the beta2-adrenergic receptor, which plays a key role in relaying messages in the body from hormones, serotonin and other molecules. Medicines ranging from antihistamines to beta blockers target such receptors, and the new findings could lead to improved drugs.
- Beyond silicon: Advances in transition metal oxides may herald the next revolution in materials for microcircuitry. Researchers are optimistic that new combinations of oxides will eventually outperform semiconductors.
- A new spin for electrons: Experiments confirmed what theorists had previously predicted about a phenomenon known as the quantum spin Hall effect in electrons. If the effect works at room temperature, it could lead to a new breed of low-power "spintronic" computers.
- A new approach for vaccines: Researchers found that when the immune system's T cells divide, two types of proteins are generated — "soldier" proteins that fight off a virus or tumor immediately, and "memory cell" proteins that could lie in wait for years to fight off the intruder another day. The finding could result in improved vaccines.
- Streamlining chemistry: A variety of discoveries point the way to more efficient methods for synthesizing organic compounds. The potential result? Cheaper drugs and other synthetics.
- How imagination works: Studies in humans and rats suggest that memory and imagination are both rooted in the hippocampus — leading researchers to propose that the brain splices together remembered fragments of past events to construct possible futures.
- Game over: Scientists developed software that "solved" the game of checkers, effectively making the computer unbeatable at one of the oldest games in history. The researchers demonstrated that the game will always end in a draw if neither player makes a mistake.
Science also identified seven research trends to watch in 2008:
- Particle physics: The world's biggest particle accelerator, Europe's Large Hadron Collider, is due to start up next spring, and physicists hope it will reveal new particles and solve old cosmic puzzles. But big discoveries take time. "Call it a major success of the LHC produces even a little data next year," the editors said.
- MicroRNA: The small RNA molecules that control gene expression are increasingly attracting interest from geneticists. "In 2008, researchers will start using microRNAs to unveil disease mechanisms and will make inroads into solving fundamental puzzles about how they function," the editors said.
- Synthetic genomics: Over the next year, scientists hope to "boot up" cells using synthesized DNA — a technique that eventually could lead to microbe-derived biofuels and pharmaceuticals.
- Paleogenomics: Genetic analysis of fossil bones has already yielded fresh information about the long-extinct Neanderthals, leading to more informed comparisons with Homo sapiens. A rough draft of the Neanderthal genome is expected by the end of 2008 — and there may be more extinct genomes out there that can be at least partially revived.
- Multiferroics: These compounds, which are relatives of ceramic oxide superconductors, may soon be shaped into novel computer-chip devices.
- Microbial genomes: Labs around the world are beginning to analyze the myriads of microbes inside our bodies. Meanwhile, other researchers are mapping the distribution of microbes in other environments, including icebergs and hot ash.
- Neuroscience: Studies in mice and humans promise to yield important insights into how neural circuits work — and how they break down in brain disorders.
A perennial entry on the breakthrough list, global climate change, "broke from the pack this year" and was put in a class by itself, Science said.
"In 2007, the debate about the reality of global warming ended, at least in the political and public realms in the United States," Science's Eli Kintisch and Richard A. Kerr wrote.
The journal cited this year's Nobel Peace Prize, won by former Vice President Al Gore and the Intergovernmental Panel on Climate Change, as further evidence that climate concerns had entered the mainstream.
The challenges to come fall mainly in the policy sphere, but still more scientific breakthroughs may be required: "Growing numbers of prominent climate experts are calling for research into geoengineering, the deliberate tinkering with Earth's climate to reverse warming," Science noted.