My son has to do summaries of 9 current events that are related to science and explain how they are related to science. I feel kind of dumb about this because "science" is a very broad term in my opinion. As far as I know....biology is the study of life (which I assume is in the "science" category) so I would assume anything that happens in the news has something to do with life. Does anyone know any links or any suggestions??? Sorry...I feel helpless on this one so I need someone to help me help him. Thanks in advance!
Need help with current events that are related to science?...........?opera house This is sort of a trick question, because EVERYTHING relates back to science in some way. Science isn't just the things that immediately come to mind, such as biology and physics. There are also the social sciences such as economics, and applied sciences such as computer science.
Here's a list of fields of science that you can use to help you identify different news stories with a different aspect of science:
Natural Sciences: space sciences, earth science, environmental science, life science, chemistry, physics.
Social Sciences: economics, psychology, political science, geography, sociology.
Applied Sciences: engineering, computer science, and health sciences and medicine
I hope this helps.
Need help with current events that are related to science?...........?dream theater opera theaterthank u so much.....................u have really helped me a lot god blessssssssssss Report It
Look up "man Sheep" on like CNN or msnbc. Part man-part sheep, look it up. It's 20 percent human, actually
Global warming is a current event.The drought in Australia is pretty bad with us having the need to have water restrictions.The River Murray Darling is an important to us because a lof people rely on the water way .Type in River Murray Darling River and effects of drought.Birds and other wildlife rely on this important system.Look in the papers.Try the science section on Yahoo Answers.You may get better answers.
maybe...it will help you with this facts..........
1.)Adaptive Optics Pinpoints Two Supermassive Black Holes In Colliding Galaxies.
Science Daily — Astronomers have used powerful adaptive optics technology at the W. M. Keck Observatory in Hawaii to reveal the precise locations and environments of a pair of supermassive black holes at the center of an ongoing collision between two galaxies 300 million light-years away.
The new observations of the galaxy merger known as NGC 6240 reveal that each of the black holes resides at the center of a rotating disk of stars and is surrounded by a cloud of young star clusters formed in the merger, said Claire Max, professor of astronomy and astrophysics at the University of California, Santa Cruz.
"People had observed this pair of colliding galaxies at different wavelengths and seen what they thought were the black holes, but it's been very hard to make sense of how the observations at various wavelengths correspond to each other," Max said. "The adaptive optics results enabled us to tie it all together, so now we can really see it all--the hot dust in the infrared, the stars in the visible and infrared, and the x-rays and radio emissions coming from right around the black holes."
Adaptive optics (AO) enables astronomers to counteract the blurring effects of turbulence in Earth's atmosphere, which degrades images seen by ground-based telescopes. Max, who directs the Center for Adaptive Optics at UC Santa Cruz, is the lead author of a paper describing the new findings published by the journal Science. Her coauthors are Gabriela Canalizo, who worked with Max as a postdoctoral researcher at Lawrence Livermore National Laboratory (LLNL) and is now at UC Riverside, and Willem de Vries, a physicist with LLNL and UC Davis.
Images of NGC 6240 in visible light from the Hubble Space Telescope show the outer parts of the colliding galaxies distorted by their ongoing merger into long tidal tails of stars, gas, and dust. In the bright central region, two distinct nuclei can be discerned, but clouds of dust obscure much of the visible light from the core. The presence of two supermassive black holes in NGC 6240 was first demonstrated by x-ray observations from NASA's Chandra X-ray Observatory in 2002. Two pointlike radio sources were also detected in the central region.
But trying to match up the data from one instrument with those obtained at different wavelengths by other instruments is very difficult because there are few common reference points in the various wavelength regimes, Max said. The infrared images her group obtained using the AO system on the 10-meter Keck II Telescope provided the high spatial resolution needed to identify features in NGC 6240 that can be seen in different wavelengths.
"With the infrared images we got at Keck, we were able to line up the information from all the different wavelengths to determine which features in the images are the black holes," Max said.
The infrared wavelengths are less affected by dust than visible light, and the Keck infrared images show distinct nuclei with complex substructure surrounded by many faint point sources. The faint point sources are young star clusters produced in a burst of star formation triggered by the collision of the two gas-rich galaxies. Pinpointing which of the features in the infrared images correspond to the positions of the black holes involved several steps and required Keck adaptive optics observations at different infrared wavelengths.
"We uncovered it piece by piece, until we were able to make the correspondence between the black holes and the features seen at different wavelengths, as well as the stuff around them," Max said. "It really shows how powerful the Keck adaptive optics system is. We were also fortunate to have an extraordinarily good observing night."
Galaxy mergers are thought to play a major role in the evolution of galaxies and may help explain many of their properties. For example, astronomers have found that the mass of the black hole at the center of a galaxy is highly correlated with large-scale properties of the galaxy itself. The "coevolution" hypothesis explains this correlation as the result of both the black hole and the galaxy around it growing incrementally in repeated merger events over cosmic timescales.
"The gravitational influence of the black hole is actually limited to a relatively small region right around it, so how can it affect the rest of the galaxy" But if the black hole and the galaxy around it evolved together through the same sequence of merger events, that would explain the correlations," Max said. "That's why people are so excited about understanding galaxy mergers, and here we're seeing it in action."
The two black holes in NGC 6240 will eventually, in 10 million to 100 million years, spiral into each other and merge, producing a powerful burst of gravitational radiation, she said.
Note: This story has been adapted from a news release issued by University of California - Santa Cruz.
2.)Scientists Put 'Spin' In Silicon, Advance New Age Of Electronics.
Science Daily — Electrical engineers from the University of Delaware and Cambridge NanoTech have demonstrated for the first time how the spin properties of electrons in silicon--the world's most dominant semiconductor, used in electronics ranging from computers to cell phones--can be measured and controlled.
The discovery could dramatically advance the nascent field of spintronics, which focuses on harnessing the magnet-like “spin” property of electrons instead of solely their charge to create exponentially faster, more powerful electronics such as quantum computers.
The experiment, conducted in the laboratory of Ian Appelbaum, assistant professor of electrical and computer engineering at UD, with doctoral student Biqin Huang, and in collaboration with Douwe Monsma, co-founder of Cambridge NanoTech in Cambridge, Mass., is reported in the May 17 issue of the prestigious scientific journal Nature.
In commenting on the UD team's research findings in the “News and Views” section, which also was published in the Nature edition, Igor Zutic of the Department of Physics at the State University of New York at Buffalo, and Jaroslav Fabian, of the Institute of Theoretical Physics at the University of Regensburg in Germany, note, “Modern computers present serious challenges for conventional, silicon-based electronics.
Ever-increasing demands on processor speed, memory storage and power consumption--the era of the laptop that can keep us warm in winter is fast upon us--are forcing researchers to explore unfamiliar territory in the quest for increased performance. In these endeavours, Appelbaum and colleagues report a possibly decisive development: the first demonstration of the transport and coherent manipulation of electron spin in silicon.”
While manipulating electron charge is the basis of the present-day electronics industry, researchers in academia and industry over the past decade have been exploring the capability of electron spin to carry, process and store information. A major goal in spintronics is to reach the precise level of control over electron spin that modern electronics has executed over electron charge.
“An electron has intrinsic angular momentum called spin,” Appelbaum noted. “The first step to making spintronic devices and circuits is to inject more spins of one direction than in the opposite direction into a semiconductor."
Silicon has been the workhorse material of the electronics industry, the transporter of electrical current in computer chips and transistors. Silicon also has been predicted to be a superior semiconductor for spintronics, yet demonstrating its ability to conduct the spin of electrons, referred to as “spin transport,” has eluded scientists--until now.
To provide conclusive evidence of spin transport in silicon, Appelbaum and Huang fabricated small, silicon semiconductor devices using a custom-built, ultra-high vacuum chamber for silicon-wafer bonding.
After spin injection, electrons in the silicon were then subjected to a magnetic field, which caused their spin direction to “precess” or gyrate (much like gravity's effect on a rotating gyroscope), producing tell-tale oscillations in their measurement.
“The processes of precession and dephasing, or decay, are the most unambiguous hallmarks for spin transport. Our work is the first time anyone has shown this effect in silicon,” Appelbaum said.
“It's an important problem to solve because silicon is the most important semiconductor for electronics,” Appelbaum noted. “However, methods that worked for spin detection in other semiconductors failed in silicon.”
Appelbaum said that pursuing the research was a risk worth taking. He credits Monsma with introducing him to hot-electron spin transport and applying it to the problem of spin detection in silicon several years ago when they were postdoctoral fellows together at Harvard University.
Originally, when Appelbaum entered college as an undergraduate at Rensselaer Polytechnic Institute, he thought he wanted to become a physician. But a professor there, Stephen Nettel, turned him on to physics and electrical engineering, and now Appelbaum is teaching his UD students using Nettel's textbook.
So while Appelbaum decided not to become a medical doctor, in some circles he might now be considered, literally, a “spin” doctor.
“We hope we're with spintronics where Bell Labs was with semiconductor electronics in 1948,” Appelbaum said.
That year, Bell announced the invention of the transistor, which laid the foundation for modern electronics.
Appelbaum's research was supported by grants from the U.S. Office of Naval Research and by the Microsystems Technology Office of the Defense Advanced Research Projects Agency (DARPA), which is the central research and development organization for the U.S. Department of Defense.
3.)New Process Generates Hydrogen From Aluminum Alloy To Run Engines, Fuel Cells.
Science Daily — A Purdue University engineer has developed a method that uses an aluminum alloy to extract hydrogen from water for running fuel cells or internal combustion engines, and the technique could be used to replace gasoline.
The method makes it unnecessary to store or transport hydrogen - two major challenges in creating a hydrogen economy, said Jerry Woodall, a distinguished professor of electrical and computer engineering at Purdue who invented the process.
"The hydrogen is generated on demand, so you only produce as much as you need when you need it," said Woodall, who presented research findings detailing how the system works during a recent energy symposium at Purdue.
The technology could be used to drive small internal combustion engines in various applications, including portable emergency generators, lawn mowers and chain saws. The process could, in theory, also be used to replace gasoline for cars and trucks, he said.
Hydrogen is generated spontaneously when water is added to pellets of the alloy, which is made of aluminum and a metal called gallium. The researchers have shown how hydrogen is produced when water is added to a small tank containing the pellets. Hydrogen produced in such a system could be fed directly to an engine, such as those on lawn mowers.
"When water is added to the pellets, the aluminum in the solid alloy reacts because it has a strong attraction to the oxygen in the water," Woodall said.
This reaction splits the oxygen and hydrogen contained in water, releasing hydrogen in the process.
The gallium is critical to the process because it hinders the formation of a skin normally created on aluminum's surface after oxidation. This skin usually prevents oxygen from reacting with aluminum, acting as a barrier. Preventing the skin's formation allows the reaction to continue until all of the aluminum is used.
The Purdue Research Foundation holds title to the primary patent, which has been filed with the U.S. Patent and Trademark Office and is pending. An Indiana startup company, AlGalCo LLC., has received a license for the exclusive right to commercialize the process.
The research has been supported by the Energy Center at Purdue's Discovery Park, the university's hub for interdisciplinary research.
"This is exactly the kind of project that suits Discovery Park. It's exciting science that has great potential to be commercialized," said Jay Gore, associate dean of engineering for research, the Energy Center's interim director and the Vincent P. Reilly Professor of Mechanical Engineering.
The research team is made up of electrical, mechanical, chemical and aeronautical engineers, including doctoral students.
Woodall discovered that liquid alloys of aluminum and gallium spontaneously produce hydrogen if mixed with water while he was working as a researcher in the semiconductor industry in 1967. The research, which focused on developing new semiconductors for computers and electronics, led to advances in optical-fiber communications and light-emitting diodes, making them practical for everything from DVD players to automotive dashboard displays. That work also led to development of advanced transistors for cell phones and components in solar cells powering space modules like those used on the Mars rover, earning Woodall the 2001 National Medal of Technology from President George W. Bush.
"I was cleaning a crucible containing liquid alloys of gallium and aluminum," Woodall said. "When I added water to this alloy - talk about a discovery - there was a violent poof. I went to my office and worked out the reaction in a couple of hours to figure out what had happened. When aluminum atoms in the liquid alloy come into contact with water, they react, splitting the water and producing hydrogen and aluminum oxide.
"Gallium is critical because it melts at low temperature and readily dissolves aluminum, and it renders the aluminum in the solid pellets reactive with water. This was a totally surprising discovery, since it is well known that pure solid aluminum does not readily react with water."
The waste products are gallium and aluminum oxide, also called alumina. Combusting hydrogen in an engine produces only water as waste.
"No toxic fumes are produced," Woodall said. "It's important to note that the gallium doesn't react, so it doesn't get used up and can be recycled over and over again. The reason this is so important is because gallium is currently a lot more expensive than aluminum. Hopefully, if this process is widely adopted, the gallium industry will respond by producing large quantities of the low-grade gallium required for our process. Currently, nearly all gallium is of high purity and used almost exclusively by the semiconductor industry."
Woodall said that because the technology makes it possible to use hydrogen instead of gasoline to run internal combustion engines it could be used for cars and trucks. In order for the technology to be economically competitive with gasoline, however, the cost of recycling aluminum oxide must be reduced, he said.
"Right now it costs more than $1 a pound to buy aluminum, and, at that price, you can't deliver a product at the equivalent of $3 per gallon of gasoline," Woodall said.
However, the cost of aluminum could be reduced by recycling it from the alumina using a process called fused salt electrolysis. The aluminum could be produced at competitive prices if the recycling process were carried out with electricity generated by a nuclear power plant or windmills. Because the electricity would not need to be distributed on the power grid, it would be less costly than power produced by plants connected to the grid, and the generators could be located in remote locations, which would be particularly important for a nuclear reactor to ease political and social concerns, Woodall said.
"The cost of making on-site electricity is much lower if you don't have to distribute it," Woodall said.
The approach could enable the United States to replace gasoline for transportation purposes, reducing pollution and the nation's dependence on foreign oil. If hydrogen fuel cells are perfected for cars and trucks in the future, the same hydrogen-producing method could be used to power them, he said.
"We call this the aluminum-enabling hydrogen economy," Woodall said. "It's a simple matter to convert ordinary internal combustion engines to run on hydrogen. All you have to do is replace the gasoline fuel injector with a hydrogen injector."
Even at the current cost of aluminum, however, the method would be economically competitive with gasoline if the hydrogen were used to run future fuel cells.
"Using pure hydrogen, fuel cell systems run at an overall efficiency of 75 percent, compared to 40 percent using hydrogen extracted from fossil fuels and with 25 percent for internal combustion engines," Woodall said. "Therefore, when and if fuel cells become economically viable, our method would compete with gasoline at $3 per gallon even if aluminum costs more than a dollar per pound."
The hydrogen-generating technology paired with advanced fuel cells also represents a potential future method for replacing lead-acid batteries in applications such as golf carts, electric wheel chairs and hybrid cars, he said.
The technology underscores aluminum's value for energy production.
"Most people don't realize how energy intensive aluminum is," Woodall said. "For every pound of aluminum you get more than two kilowatt hours of energy in the form of hydrogen combustion and more than two kilowatt hours of heat from the reaction of aluminum with water. A midsize car with a full tank of aluminum-gallium pellets, which amounts to about 350 pounds of aluminum, could take a 350-mile trip and it would cost $60, assuming the alumina is converted back to aluminum on-site at a nuclear power plant.
"How does this compare with conventional technology? Well, if I put gasoline in a tank, I get six kilowatt hours per pound, or about two and a half times the energy than I get for a pound of aluminum. So I need about two and a half times the weight of aluminum to get the same energy output, but I eliminate gasoline entirely, and I am using a resource that is cheap and abundant in the United States. If only the energy of the generated hydrogen is used, then the aluminum-gallium alloy would require about the same space as a tank of gasoline, so no extra room would be needed, and the added weight would be the equivalent of an extra passenger, albeit a pretty large extra passenger."
The concept could eliminate major hurdles related to developing a hydrogen economy. Replacing gasoline with hydrogen for transportation purposes would require the production of huge quantities of hydrogen, and the hydrogen gas would then have to be transported to filling stations. Transporting hydrogen is expensive because it is a "non-ideal gas," meaning storage tanks contain less hydrogen than other gases.
"If I can economically make hydrogen on demand, however, I don't have to store and transport it, which solves a significant problem," Woodall said.
Note: This story has been adapted from a news release issued by Purdue University.
4.)New Species Of Sea Anemone Found In Deepest Pacific.
Science Daily — Researchers cruising for creatures that live in the deepest parts of the Pacific Ocean found a new species of sea anemone living in the unlikeliest of habitats – the carcass of a dead whale.
A marine biologist would say that discovering a new sea anemone isn't so unusual. But finding one that calls a dead whale home is what sets this new creature apart.
Since the scientists who initially found these animals weren't sea anemone specialists, they sent the 10 specimens they collected to Meg Daly, an assistant professor of evolution, ecology and organismal biology at Ohio State University . Daly runs one of the very few laboratories in the world equipped to study sea anemones.
“These creatures were so cool simply because we knew that no sea anemone had ever been found on a whale fall,” she said.
Once a whale dies, its carcass sinks to the bottom of the ocean. Scientists call this a “whale fall.” The anemones that Daly received once lived on the bones of a dead whale some 1.8 miles (3,000 meters) below sea level in a region of the Pacific Ocean called Monterey Canyon, roughly 25 miles off the coast of Monterey, Calif. All of the specimens currently in Daly's collection came from this whale fall.
The anemone, given the scientific name Anthosactis pearseae – there is no English name for it – is small and white and roughly cube-shaped. It's about the size of a human molar, and even looks like a tooth with small tentacles on one side.
Daly and Luciana Gusm?o, a doctoral student in Daly's laboratory, describe A. pearseae in detail in a recent issue of the Journal of Natural History. The two assigned the anemone to the genus Anthosactis primarily due to the roughly uniform length of A. pearseae's tentacles – a characteristic common to this group of about seven sea anemones.
“We tend to differentiate Anthosactis species from other groups of sea anemones by a variety of traits, rather than any one unique attribute,” Daly said.
She and Gusm?o named A. pearseae after Vicki Pearse, the naturalist who first collected the specimens during a cruise of the Monterey Bay Aquarium Research Institute's research vessel the Western Flyer. Pearse is a research associate at the Institute of Marine Sciences at the University of Santa Cruz.
It's customary to name a newly discovered plant or animal species after the person who found it, or after the place where it was discovered.
Collecting deep-sea creatures is a tedious process that involves a lot of high-tech equipment like underwater video cameras attached to remotely operated vehicles (ROVs). Deep sea ROVs are also equipped with robotic arms and suction devices that are used to collect species.
“It's like a submarine that's manned from the surface,” said Daly, who plans to head to Monterey Canyon later this year in hopes of finding more dead whales with A. pearseae roosting on the bones. A successful trip could answer some of Daly's lingering questions about the species itself and, more broadly, may provide clues on how human activities affect this unique, seemingly removed ecosystem.
“The thing about these communities is that they seem so ephemeral and so unplanned,” Daly said. “A whale dies where it dies, and its carcass lands wherever. But these are actually some of the most stable deep sea communities.
“A better understanding of deep-sea populations may shed light on how humans drive ecological change, whether it's through whaling or global climate change,” she said, and also pointed out that there are now far fewer major whale migrations along the California coast.
While the flesh of a dead whale decomposes within weeks, the bones can last anywhere from 60 to 100 years.
“As that happens, the bacteria that break down the bones release sulfur,” Daly said. “A whole community of aquatic creatures uses that sulfur to make energy, much like plants convert light into energy.”
Daly doesn't know much about A. pearseae beyond its physical description. She and Gusm?o aren't sure how old the creatures are, and say that sea anemones can live for hundreds of years. Nor are they sure how A. pearseae reproduce (each anemone may have male and female sex organs), or if it lives exclusively on whale carcasses.
“So far, a single dead whale is the only place where we've found these anemones,” Daly said.
She and Gusm?o plan to include A. pearseae in a long-term evolutionary study of genetic relationships among sea anemones. A. pearseae belongs to an extremely diverse group of anemones, Daly said, and comparing the anemones' genetic sequences may clue the researchers in to how the different species evolved over time.
Note: This story has been adapted from a news release issued by Ohio State University.
5.)Clock Gene Plays Role In Weight Gain, Study Finds.
Science Daily — Scientists at the University of Virginia and the Medical College of Wisconsin have discovered that a gene that participates in the regulation of the body’s biological rhythms may also be a major control in regulating metabolism. Their finding shows that mice lacking the gene Nocturnin, which is regulated by the circadian clock in the organs and tissues of mammals, are resistant to weight gain when put on a high fat diet and also are resistant to the accumulation of fat in the liver. This new understanding of weight gain could potentially lead to therapies for inhibiting obesity and for treating its effects on health.
“It’s been known for some time that there are many links between the circadian clock and various aspects of physiology and metabolism,” said Carla Green, the study’s lead author and an associate professor of biology at the University of Virginia. “This study suggests that Nocturnin is part of the network that the circadian clock uses to control important aspects of metabolism. A better understanding of Nocturnin’s function could eventually lead to medical treatments that could counteract the problems of obesity, which has become a major issue in modern society.”
Biological clocks are the body’s internal timekeepers that regulate organs and activity/rest cycles by controlling energy levels, alertness, growth, moods and the effects of aging. Research in this field has many health implications for dealing with aging, jet lag, sleep disorders, shift work and dieting.
Green and her colleagues used regular mice and genetically altered mice in which the Nocturnin gene was knocked out. The Nocturnin-deficient mice were divided into two groups; one group fed a normal diet, the other a very high fat diet. A group of normal mice were also fed a high fat diet. The researchers found that both groups of the genetically altered mice maintained normal weight and activity levels, and, of particular interest, the ones fed the high fat diet gained only slight weight even over long periods of time. The normal mice on the high fat diet, however, “ballooned,” gaining more than twice the weight of the Nocturnin-deficient mice. And when the mice were dissected, the researchers discovered that the normal mice had, as expected, large concentrations of fat on their livers, whereas the altered mice had normal levels of fat in their livers.
“We were quite amazed at what we found,” Green said. “We thought that over time, as we continued to feed the mutant mice the high fat diet, that they would eventually gain weight at some expected rate, but it never happened. These mice continued to stay slim while the normal mice nearly doubled in weight and developed fatty livers.”
Green said it is possible that, “after a great deal of further research, a drug possibly could be developed that would inhibit Nocturnin and reduce the risk of developing obesity.”
Clock genes in the body’s organs operate in conjunction with a central time keeper in the brain, the hypothalamic suprachiasmatic nucleus, but also work somewhat independently, resulting in a complex system of oscillators regulating various functions of the body.
Scientists are working to better understand how the genes and proteins of the circadian clock in mammals affect not only activity cycles but also metabolism, which are tied to feeding cycles. Circadian rhythms were set in motion early in the history of life on the planet, and tied through evolution to the astronomical cycles that effect Earth’s environment, the rise and setting of the sun, and the passing of seasons.
The study is published in the journal Proceedings of the National Academy of Sciences. Green’s co-researchers include Nicholas Douris, a U.Va. graduate student who designed the study, U.Va. post-doctoral fellow Shihoko Kojima, and Joseph Besharse of the Medical College of Wisconsin.
Note: This story has been adapted from a news release issued by University of Virginia.
6.)Cancer Agressiveness 'Triggered' By Bacteria.
Science Daily — New research in lymphatic cancer shows that bacteria can cause cancer to be more aggressive. Patients with skin lymphoma may benefit from antibiotic treatments used for bacteria-infections.
How does it work?
Patients with lymphatic cancer in the skin often have bacteria-infections, which shows as e.g. eczema or skin-sores. The research results indicate that bacteria can aggravate the cancer. The bacteria activates the immune system, which indirectly stimulates the cancer cells to spread further.
Professor Niels ?dum from Department of Molecular Biology, University of Copenhagen says: - The results are surprising. Further research is necessary to completely understand the mechanisms between the immune response and development of lymphatic cancer, but we know that more than half of the patients suffering from lymphatic cancer in the skin also get bacteria skin-infections. We have helped to show how these bacteria can affect the cancer disease in a negative way, and that this may be relieved by a simple antibiotic treatment.
The research was conducted by a group of researchers from University of Copenhagen, University of Pennsylvania and Copenhagen University Hospital, and is funded by The Danish Cancer Society. The results are published in “Blood” (Journal of the American Society of Hematology).
Note: This story has been adapted from a news release issued by University of Copenhagen.
7.)New Method To Track Immune System Enzyme In Live Animals Developed.
Science Daily — Scientists supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) at the National Institutes of Health have created two mouse strains that will permit researchers to trace, in a live animal, the activity of an enzyme believed to play a crucial role both in the normal immune response as well as autoimmunity and B cell tumor development.
The enzyme, known as activation-induced cytidine deaminase or AID (which has no relation to the AIDS virus), is expressed by B cells, which are produced in the bone marrow and are responsible for making antibodies that attack foreign invaders such as viruses and bacteria. The enzyme enables the cells to respond with precision to the almost limitless types of invaders the body may encounter. Unfortunately, it also has a down side.
B cells constantly scan the body for foreign invaders, explains Rafael Casellas, Ph.D., an investigator in NIAMS’ Molecular Immunology and Inflammation Branch and lead author of the paper. As B cells encounter foreign antigens from viruses, bacteria or allergens, they migrate to germinal centers — specialized microenvironments in tonsils, spleen and lymph nodes. Within germinal centers, B cells divide extensively and express the AID enzyme, which causes random mutations and recombination in the cells’ immunoglobulin (antibody) genes. For the most part, these genetic changes are beneficial because they enable B lymphocytes to attack and stop the invader. In some cases, however, AID-dependent alterations in the genetic material of B cells can also lead to unwanted results such as autoimmunity and development of B cell tumors, as in the case of Burkitt lymphoma.
“It becomes crucial that we comprehend how AID is regulated during the normal immune response as well as in tumorigenesis and autoimmunity,” says Casellas. The problem with understanding how AID is regulated or deregulated is that there has not been an easy way to visualize the enzyme’s action in a living animal — until now.
To address this issue, Dr. Casellas and his colleagues created transgenic mice that had a green fluorescent protein derived from jellyfish fused to the AID enzyme. In these transgenic animals, B cells express the tagged enzyme during the immune response. In a second mouse strain, Casellas and coworkers expressed permanently a yellow fluorescent protein in the progeny of germinal center B cells. “Thanks to these new mouse models, we can track in live animals whenever the AID enzyme is active as well as the result of that activity,” says Casellas. Scientists can also cross these new mouse strains with mice predisposed to B-cell tumors or autoimmunity to see differences in enzyme expression in health and disease.
NIAMS Director Stephen I. Katz. M.D., Ph.D., believes these new tools have great potential to help solve some mysteries of the immune system, such as the causes of B-cell tumors and autoimmunity. “The better we understand these problems,” he says, “the closer we come to better treatments for them and eventually, perhaps, ways to prevent them.”
This work was also supported by the National Cancer Institute.
Article: Crouch E, et al. Regulation of AID expression in the immune response. J Exp Med 2007; 204:1145-1156.
Note: This story has been adapted from a news release issued by NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases.
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