Social Slime Mold
A new study finds that some strains of this social amoeba, called Dictyostelium discoideum, pack bacteria snacks with them before they travel. Once the amoebae reach their destination, they seed the area with the bacteria, ensuring any amoeba offspring will have plenty to eat. Here, the social amoebae fruiting bodies with spores are shown.
Beauty in Embryos
Anarchic Blood Vessels
Research has shown that inexpensive omega-3 supplements may ease retinopathy. A new study of mice published Feb. 9 in the journal Science Translational Medicine finds that the supplements do so by reducing runaway blood vessel growth. Clinical trials in humans are underway.
Love in the Time of Giardia
Favorite Microbe Hangouts
Currently in its eighth year, the international competition honors recipients who use visual media to promote understanding of scientific research. The criteria for judging the entries included visual impact, effective communication, freshness and originality.
That was surely the case for the HIV illustration. Ivan Konstantinov and his team's winning illustration depict the most highly detailed 3D structural model of the human immunodeficiency virus (HIV) ever made. "We consider such 3-D models as a new way to present and promote scientific data about ubiquitous human viruses," said Ivan Konstantinov, one of the scientists who created the illustration.
Konstantinov said his team tried to show the viral particle in as real a light as possible. "While working on the HIV model, over 100 articles from leading scientific journals were analyzed," he said. "For this project, Dr. Yegor Voronin from the Global HIV Vaccine Enterprise helped us evaluate the data, shared recent findings and views in the field, and provided general advice."
The image snagged a spot on the Wellcome Image Awards 2011, which chooses the most striking and technically excellent images acquired by the Wellcome Images picture library in the prior 18 months.
How Does Your Embryo Grow?
The new study finds that the cells at the edges of the sheet covering the yolk don't divide. Instead, actively dividing cells in the interior (shown here in blue, purple and orange) migrate out to grow the sheet. But the study isn't just an excuse to label cells with pretty colors; researchers hope an understanding of how cells migrate over large distances will help them develop treatments for wound healing and cancer.
In a Drop of Water
Hitch a Ride on a Dragonfly
Small But Social
Some bacteria try to game the system, however, by jockeying to become the hardy spore rather than the supporting fruiting body.
A new study published in the journal Proceedings of the National Academy of Sciences finds that some bacteria in the community evolve to "police" these cheaters, a very primitive form of social cooperation.
It's Not Grandma's Lace
— Stephanie Pappas
Are We In Outer Space?
The space between cells is a freeway when you're a Staphylococcus bacterium. A tight barrier of cells is supposed to prevent outside invaders like these Staph bugs (red and purple) from entering the body. The fact that we get sick is testimony that those barriers sometimes fail. Now, University of Pennsylvania researchers have found one reason why: Some pathogenic bugs have the key that opens secret passages in this cellular wall.
The surface cells in the respiratory system (shown here in blue) let their guard down when they come in contact with certain pathogen molecules. These molecules trigger the respiratory cells to stop producing proteins that keep the junctions between cells tight. Once that happens, it's no problem for the tiny, deadly microbes to breeze through like they own the place.
— Stephanie Pappas
Who's Doing the Wave?
These are a laboratory-built version of cilia, tiny hair-like projections off of a cell body. In a cell, cilia beat in synchronization much like "The Wave" so beloved by sports fans, propelling a cell or brushing away foreign material (cilia in our lungs help expel inhaled particles, for example.)
Using just four cellular components, researchers at Brandeis University in Massachusetts found that they could build super-simple cilia that automatically sync up with one another, beating in perfect rhythm. We'd like to see a bunch of drunk baseball fans manage that.
— Stephanie Pappas
Tiny Feet Take Big Steps for Cancer Cells
The spread of cancer from one its initial outpost to someplace else in the body, called metastasis, is the most common reason cancer treatments fail. Some cancer cells rely on microscopic "feet" called invadopodia, which are projections on the cellular membrane that help the cells "walk" to surrounding tissues. Now researchers are reporting online in the July 26, 2011, issue of the journal Science Signaling that they have identified compounds that inhibit invadopodia formation without causing toxicity. The team also found a number of compounds that increased a cancer cell's invadopodia.
Here, invadopodia (bright red dots) form on metastatic cancer cells.
The Forest in Your Eye
Scientists at the Max Planck Institute for Medical Research in Heidelberg made this image using new brain-mapping software that traces the connections between nerve cells 50 times faster than earlier methods. The process has now been tested on the mouse retina, as seen above, and researchers plan to tackle the rodent's cerebral cortex next. For more amazing brain images, check out LiveScience's gallery, Inside the Brain: A Journey Through Time.
How Do Your Guts Grow?
Here, a chick's gut melds with a numerical simulation of chicken gut development.
— Stephanie Pappas
Eggshells Hold Hidden Worlds
This image was taken during microscopic studies on the spatial structure of the eggshell in the pheasant and was an entry in the 2005 Science & Engineering Visualization Challenge (SciVis) competition, sponsored by the National Science Foundation and the Journal Science. The competition is held each year to recognize outstanding achievements by scientists, engineers, visualization specialists and artists who are innovators in using visual media to promote the understanding of research results and scientific phenomena. To learn more about the competition and view all the winning entries, see the SciVis Special Report. (Date of Image: May 30, 2005.)
Worm's Inner World
The tubes accomplish this trick thanks to bulb-like structures called flame cells, which contain cilia that move the fluids out toward the skin.
— Stephanie Pappas
— Stephanie Pappas
Amazing Itsy-Bitsy Rainbow
Tiny, But Deadly
What in the World?
One reason for this extra fecundity, a new study finds, is that cells divide more readily into gametes (the cells that combine to form offspring, like sperm and egg in humans) in infected female insects. Programmed cell death also drops in developing egg chambers, like those seen in the photograph. Because disease-carrying bugs such as mosquitoes are infected by Wolbachia, researchers hope their results, reported online in Science Oct. 20, will help in developing controls on insect reproduction.
New Age-Defying Trick
The researchers speculate that boosting the fruit fly version of PGC-1 stimulates the stem cells that replenish the intestinal tissues, keeping the flies' intestines healthier. The findings, which are detailed in the journal Cell Metabolism, suggest that the fruit fly version of PGC-1 can act as a biological dial for slowing the aging process and might serve as a target for drugs or other therapies to put the breaks on aging and age-related diseases.
(Shown here is a fruit-fly intestine with the different colors representing different cell types; as fruit flies age unregulated stem cell activity and the inability to form cells with specialized functions goes awry.)
Colorful and Cerebral
Reporting Dec. 12 in the journal Neuron, Norwegian and German scientists say they've used a supercomputer to better understand how the babble of thousands of nerve cells "talking" to one another translates when recorded onto an electrode of the sort used for electroencephalograms (EEGs). This translation effort should make it easier to design brain implants that help control epilepsy, or even enable a paralyzed patient to move his or her limbs with brain waves, the researchers said.
Avian flu rarely jumps from human to human, which is fortunate because the virus kills about 60 percent of people it does infect (they usually get it from close contact with poultry). Researchers from the Netherlands and from Wisconsin caused a stir in December when they published a paper revealing how they'd made avian flu go airborne in ferrets, genetically engineering H5N1 to be highly contagious in mammals. It's likely the strain would work the same way in humans. This research could be important for understanding how the flu virus evolves and if it's likely to become highly transmissible on its own, but U.S. government officials, citing biosecurity fears, convinced the researchers and the journals that published the research to redact key details.
Meanwhile, avian flu flexed its muscles in Shenzhen, China, killing a 39-year-old bus driver and triggering a poultry import ban from that area in Hong Kong. The man was the first human avian flu death in 18 months.
Sewing Cells Together
This image shows the beginnings of cell-cell connections between endothelial cells, the type that make up our blood vessel walls. In green, the transmembrane protein VE-Cadherin mediates the formation of cellular junctions. The cells' nuclei are stained blue, while the red is actin, the internal "skeleton" of a cell.
Alien Life or Sparkly Decor?
Alien life? An odd extrasolar planet? Maybe an eyeball?
Perhaps just as exotic, this planktonic foraminifera called Orbulina universa evolved about 13 million years ago. The single-celled, shelled organism was captured by scuba divers from surface waters off Santa Catalina Island, Calif.
Living inside the calcite spines of this creature are other simple organisms called dinoflagellates; the dinoflagellates have formed a partnership with the foraminifera, using photosynthesis to produce foods while living in the calcium-rich spines.
At the end of their four-week life cycle, the shells from both protists (foraminifera and dinoflagellate) sink to the seafloor where they become part of the microfossil assemblage in deep-sea sediments. The geochemical compositions of such shells are used to reconstruct past ocean changes. Researchers reported in the Jan. 26 issue of the journal Science Express the importance of such geochemistry; they reported that lithium isotopes in sea sediments reflect several intense episodes of mountain-building and other major geologic events in the last 60 million years.
A Mouse's Hair Trigger
New research on sensory signals finds that a protein crucial to eye development is also important for the ability of both humans and mice to sense vibrations. The c-Maf protein is known for its importance in proper eye development; when something goes wrong with c-Maf, cataracts result. It turns out that when c-Maf mutates, Pacinian corpuscles, a kind of touch receptor specialized to detect fast vibrations, also atrophy. Humans have Pacinian corpuscles in our fingertips, meaning that one messed-up protein can damage multiple senses.
Vanderbilt University researcher Lawrence Marnett and his colleagues have discovered that COX-2 metabolizes endocannabinoids, which are naturally-occurring painkillers in the body that activate the same brain receptors as marijuana. Intriguingly, certain forms of ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs) block this metabolism, the researchers find. That means the pain-killing endocannabinoids stick around longer, partially explaining why popping an Advil can kill a headache.
Giardia has two phases in its life cycle: the cyst, a dormant phase, and the active trophozoite phase, seen here. People can contract the parasite by drinking water contaminated with cysts; from there, the parasite becomes active, with very unpleasant digestive results. Anti-parasite medication can help fight off these fierce freeloaders, which attach to the intestine lining (seen here in blue). The worm-like flagella seen in this image allow the trophozoites to swim freely in the host's gut.
The Parasite and the Protector
The findings are important, given that at least 7,000 people per year in sub-Saharan Africa contract sleeping sickness, according to the World Health Organization. As the parasite infiltrates the brain, symptoms include disturbed sleep, confusion and poor coordination. If caught early, African sleeping sickness is treatable; left untreated, it is almost always fatal.
What in the World?
You're looking at the rear end of a tiny worm called Caenorhabditis elegans, one of the most common lab animals in science. These little soil-living nematodes are only about 0.04 inches (1 millimeter) long. They're handy for scientists because they're easy to analyze genetically and simple to keep alive in the laboratory. C. elegans can even survive being frozen and thawed, making long-term storage easy.
This image comes courtesy a recent study published July 27 in the journal Science. Researchers mapped the neural connections in the nervous system of the C. elegans posterior, revealing the sexual circuits that play an important role in mating. The nerves of a worm's rear end may seem like an odd topic of study, but scientists believe that tracing these simple circuits will help them understand how the more complex neural circuits of humans and other mammals work.
The (Tiny) Face of a Killer
There's Hair Where!?
What Is This?
As the 10 nanometer scale bar gives away, you're looking at the very small. These are the scales covering the abdomen of a firefly. As it turns out, the jagged shape of the scales actually enhances the fireflies' glow, researchers report Jan. 8, 2013 in the journal Optics Express. [Top 10 Things to See With Your First Microscope]
The scientists used the example of the fireflies (genus Photuris) to design a new overlayer for LED lights that likewise brightens up the bulbs' output, making them 1.5 times more efficient than the originals.
Biomineral Single Crystals
Biomineral crystals found in a sea urchin tooth. Geologic or synthetic mineral crystals usually have flat faces and sharp edges, whereas biomineral crystals can have strikingly uncommon forms that have evolved to enhance function. The image here was captured using environmental scanning electron microscopy and false-colored. Each color highlights a continuous singlecrystal of calcite (CaCO3) made by the sea urchin Arbacia punctulata, at the forming end of one of its teeth. Together, these biomineral crystals fill space, harden the tooth, and toughen it enough to grind rock.
Hyaluronan is part of the body's chemical toolbelt for healing, but it can also promote inflammation and cancer. New research published in the Journal of Biological Chemistry finds that high sugar concentrations in the blood promote the production of hyaluronan, which may explain why diabetics have an elevated risk of breast cancer. Researchers hope that slowing hyaluronan production could slow the spread of cancerous cells.
Spiking Out to Settle Down
What in the World?
Are all the guesses in? This is an ultra-close look at a moth antenna. Male moths use their antennae to detect pheromones from females, which travel through the air in plumes (look out, your porch light may be surrounded). A new study published April 15, 2013 in the journal Proceedings of the National Academy of Sciences found that male moths aren't perfect at sniffing out the chemicals in these plumes, so they sometimes mate with strains of moths they wouldn't otherwise approach. The finding explains the number of hybrid moths in nature.