Here’s a sampling of a few science headlines from this past week—enjoy!

Grey wolves

When are grey wolves not grey wolves? According to headlines this week in Nature News and New Scientist, the grey wolves are called eastern wolves when the US Fish and Wildlife Service (FWS) wants to de-list the animals from the Endangered Species list.

Citing a publication in FWS’s own North American Fauna journal, the agency claims that the grey wolves were never historically in the regions where the species are being restored. Those were a separate, healthy species, eastern wolves.

But scientists, not to mention genetic testing, describe the eastern wolves as a sub-species of grey wolves. Read more about the science and politics in Nature News.

Crazy, dangerous fungi reproduction

Cryptococcus neoformans is a dangerous fungus that infects individuals with compromised immune systems, such as HIV/AIDS patients. It causes more than 600,000 deaths a year, accounting for a third of all AIDS-related deaths. Some strains can be drug resistant and scientists had a hard time determining why.

Like some other fungi and microorganisms, C. neoformans are both asexual and procreate with exact replicas of themselves, where the expected outcome should simply be more of the same. So how could some individuals develop drug resistance when others do not?

Now researchers, publishing in PLoS Biology, have found the act of sex between such genetically identical organisms can itself be mutagenic, meaning it can create genetic changes and diversity where it did not previously exist. In fact, in the case of the fungus C. neoformans, the process of sexual reproduction can result in extra bundles of genetic material or chromosomes that can be beneficial to the organism’s survival—such as drug resistance.

ScienceNOW has more information.

The chemistry behind whiskey

Thank goodness for Thomas Collins (that’s really his name!) of UC Davis. He’s studying the chemical compounds that make up rye and bourbon whiskeys.

Using chemistry’s latest analytical tools, Collins’s team profiled 60 American whiskeys and found that a single whiskey sample can contain hundreds of nonvolatile compounds, the ones that tend to stay in the liquid rather than evaporate off. Added up across multiple samples, the number of compounds comes to about 4,000 total, a scientific testament to the complex molecular mingling that occurs as a spirit ages, sometimes for decades, in a 53-gallon oak barrel.

Why the in-depth study? “Whiskeys’ chemical profiles could be used for distillers’ quality assurance or process improvement programs,” says Collins, who has conducted similar experiments on wine. “In addition to that, they could be used to help speed up production.”

I’ll drink to that! NPR has more details on the influence of oak barrels on whiskey flavor.

Image (fungus): Joseph Heitman

When researchers found fire salamanders (Salamandra salamandra) in the Netherlands dying at a rapid rate from a skin fungus, they thought the infection looked familiar.

Globally, amphibian numbers are declining in large part due to a chytrid fungus known as Batrachochytrium dendrobatidis or Bd. Bd attacks the skin of its host causing “the outer layers of the epidermis to thicken,” says the Academy’s amphibian expert, Dave Blackburn. “Bd disrupts the function of amphibian’s skin by interfering with electrolyte transport.”

Bd is quick and deadly: its effects may have wiped out more than 200 species of amphibians worldwide.

Similarly, the fire salamanders are dying at a rapid rate. Since first seeing dead animals in the Netherlands in 2010, scientists have observed that the population has fallen to around 10 individuals, less than four per cent of the original numbers.

But the similarities end there. The infected fire salamanders display skin lesions or ulcers and when the animals were tested, they were negative for Bd.

So what gives? According to a paper published last week in the Proceedings of the National Academy of Sciences, a new chytrid fungus.

Batrachochytrium salamandrivorans or Bs is closely related to Bd, but an entirely new chytrid fungus species.

This study is incredibly important, Blackburn says. “It clearly shows three things: 1) Bs is a new species of chytrid, 2) it presents different pathology than Bd (these lesions), and 3) it may have different host specificity.”

Bs, like Bd, doesn’t kill every amphibian it meets. “Midwife toads, Alytes obstetricans, are among the most susceptible of European frogs to Bd,” Blackburn says. But the study researchers infected the toads with new fungus Bs, and they were not susceptible to that fungus.

But the evidence the study provides only brings more questions for Blackburn. “When we think some amphibians around the world were killed by Bd, could it have been something else? Bs? Yet another species of chytrid?”

He gives an example of the thermal range for Bs and Bd. “People trying to predict how Bd spreads and where it would thrive—the fungus may be absent from that location now, but where it might flourish given the right conditions—by modeling where the disease is now with information on climatic conditions. In the past, have we been looking at the thermal range for Bd only or might we have confused some records of Bd with what we now know as Bs? Each may have different thermal conditions and there could be errors to where we’ve predicted that the disease could thrive.”

Testing for the new chytrid fungus also presents a conundrum. Although tests have been developed to screen for Bd, it is not clear whether these might sometimes be detecting Bs instead. The authors of the new study have developed primers to test for Bs, and Blackburn and his lab will obtain these to test animals here at the Academy.

Blackburn and other scientists came back with live frogs from Cameroon earlier this summer. The team hopes to raise and breed the animals here, displaying them for the public. As we reported in a story a few weeks ago, the frogs are part of a new initiative at the Academy focused on amphibian conservation and biodiversity education.

The Cameroonian frogs were screened and tested positive for Bd. They are being treated with a proven microbial solution, but now Blackburn is worried about Bs. “How widespread is Bs?”

And Blackburn has more and more questions… “Does it only affect salamanders? We’ve seen salamander declines in Central America—it looks like Bd, but could it be Bs? We found skin lesions on amphibians in Cameroon with mortality events, Bd was not present when tested. Could we have found Bs, instead?

“How is it spread, is it totally different from Bd? Why are we seeing these now? How is climate change affecting the emergence, spread, and change of prevalence? How do you stop them?

“Bs really opens the door for further research,” Blackburn says.

Image: Didier Descouens/Wikipedia

Batrachochytrium dendrobatidis (Bd) is the deadly chytrid fungus killing amphibians worldwide. Researchers have tracked the fungus to African clawed frogs (Xenopus laevis) in South Africa back to 1934, but how did it leave Africa—and those frogs—to cause the recent decline and extinction of 200 frog species worldwide?

Vance Vredenburg of San Francisco State University wants to know. In 2008, he witnessed a population of frogs he studied in Sequoia and Kings Canyon National Park drop 99.9% due to Bd.

Working with a team of researchers at Stanford, Vredenburg began looking at the herpetology collection here at the Academy. Our own Jens Vindum offered the team several specimens of African clawed frogs to swab for DNA samples. The scientists focused on specimens collected from wild populations in California between 2001 and 2010.

African clawed frogs were imported to the US between the 1930s and 1950s for use in pregnancy tests. The frogs ovulate when injected with a pregnant woman’s urine.

“Today, these frog populations are often found in or near urban areas, probably because hospitals released them into the wild when new pregnancy testing methods were invented in the 1960s,” Vredenburg says. Since then, the frogs have established feral populations throughout North America, including Golden Gate Park.

Sure enough, the Academy’s California specimens of African clawed frogs carried Bd. “This is the first evidence of the disease among introduced feral populations in the US, and it suggests these frogs may be responsible for introducing a devastating, non-native disease to amphibians in the United States,” says Vredenburg.

And although the species is a known Bd carrier, these amphibians don’t succumb to the fungus. “It’s amazing that more than half a century after being brought to California, these frogs are still here, and they still carry this highly infectious disease,” remarks Vredenburg. “This implies that there must be a stable relationship between the pathogen and the frogs, whereas there are other frog species, for example in the Sierra Nevada, which have been wiped out by the pathogen.”

The team also tested archived Academy specimens collected in Africa between 1871 and 2010 and found evidence confirming that Bd was present among indigenous populations of this species before they were exported worldwide.

Although no longer used in pregnancy testing, African clawed frogs are still imported to the US for use in biomedical and basic science research. Because of their suspected role as a carrier of the Bd fungus and other potential pathogens, eleven states have already restricted the importation of these frogs, by requiring special permits and not allowing them to be sold as pets.

The study was published last week in PLoS One.

Stay tuned—this summer, Science Today will document Vredenburg’s and Academy researcher Dave Blackburn’s fight against Bd.

Image: Michael Linnenbach/Wikipedia

By Zuberoa Marcos

White-nose syndrome has killed millions of North American bats. Now a team of U.S. scientists at The Nature Conservancy has built the first artificial cave in Tennessee to save them. The cave will open to the bats this fall.

About 5.7 million bats have already succumbed to white-nose disease in the US, according to the best estimates from state and federal wildlife officials. Originated by the aggressive Geomyces destructans fungus, it damages the bats’ wings and causes them to wake up when they should be hibernating. This burns their fat reserves too early, and the animals either starve to death or try to leave their caves in the dead of winter in search of food, often dying of exposure.

To date, there is no known treatment and the bats’ drastic decline has broad implications: the animals eat their weight in mosquitoes and other insects each day. By some estimates, they save American agriculture $3.7 billion annually.

The Nature Conservancy’s new hibernaculum hopes to protect bat populations. Made out of pre-cast concrete modules, it lies more than a meter below ground, stretches 24 meters in length, and could easily accommodate 200,000 bats.

To adapt to bats’ requirements, the cave was engineered to draw a continual supply of winter air from a concrete shaft to provide the chilly temperatures preferred by hibernating bats. The ceiling is scored with ridges and rough edges to give bat claws a tight grip. A rainwater pipe will bring in moisture to maintain the cave’s humidity levels and provide drinking water, and an air chimney will provide ventilation. Two 1.5-ton air conditioning units will run for the next few weeks to drop the cave’s temperature to the required range, between 41°F and 50°F.

The artificial cave won’t keep out the white nose fungus, but each autumn and spring, scientists plan to scrub it out with ammonia to keep it clean. Such a sanitizing procedure can’t be used in a natural cave environment because it would kill everything else and be detrimental to the ecosystem.

If the bat cave works, it will provide a new rescue plan for other endangered species. But there are no guarantees the bats will come in and use the artificial space. If they do, three surveillance cameras with infrared imaging will allow researchers to monitor bat movements without disturbing them. If they don’t, The Nature Conservancy’s experts can still use the cave as a field laboratory. They might bring some bats into the cave for testing new fungicides.

Zuberoa Marcos is a former biologist and current science writer based in Barcelona. She writes articles regularly for Science Today.

Un bunker para murciélagos

Por Zuberoa Marcos

El síndrome de la nariz blanca ha acabado con la vida de millones de murciélagos en Norteamérica. Un equipo de científicos estadounidenses de la organización The Nature Conservancy acaba de construir, en Tennessee, la primera cueva artificial para salvar a los que quedan. Empezará a funcionar este otoño.

Según estimaciones oficiales, alrededor de 5,7 millones de murciélagos en los EE.UU han sucumbido ya al síndrome de la nariz blanca. La enfermedad, originada por el hongo Geomyces destructans, daña las alas de los murciélagos y provoca que éstos se despierten cuando deberían estar hibernando. Esto hace que los animales quemen sus reservas de grasa demasiado pronto y, hambrientos, tengan que salir de la cueva, en pleno invierno, en busca de alimentos. Es una excursión mortal. Muchos de los murciélagos mueren por la exposición al frío.

Hasta la fecha, no existe un tratamiento para el síndrome de la nariz blanca a pesar de que esta drástica disminución del número de murciélagos tiene importantes consecuencias: los animales comen, cada día, su peso en mosquitos y otros insectos capaces de dañar los cultivos. Según algunas estimaciones, los murciélagos ahorran la agricultura americana 3.700 millones de dólares al año.

El nuevo hibernáculo protegerá a las poblaciones de murciélagos. Construido con módulos de hormigón prefabricados, está enterrado a un metro bajo tierra, tiene 24 metros de largo y podrá acomodar hasta a 200.000 murciélagos.

Para adaptarse a las necesidades de estos animales, la cueva ha sido diseñada para proporcionar un suministro constante de aire invernal y, con ello, las bajas temperaturas que les gustan a los murciélagos para hibernar. El techo consta de cantos y bordes ásperos para que los animales puedan agarrarse a ellos. Una tubería de agua de lluvia se encarga de mantener los niveles de humedad de la cueva y de proporcionar agua potable y una chimenea de aire de la ventilación. En las próximas semanas, dos equipos de aire acondicionado de 1.5 toneladas se encargarán de bajar la temperatura de la cueva hasta el rango necesario, entre 41 y 50 ° F.

La cueva artificial no impedirá que el hongo G. destructans entre en ella pero, cada primavera y cada otoño, los científicos la desinfectarán con amoniaco para mantenerla limpia. Este procedimiento de saneamiento no sería posible en una cueva natural, ya que sería perjudicial para el ecosistema y mataría al resto de habitantes de la misma.

Si la cueva artificial funciona, proporcionará una nueva estrategia para salvar a otras especies en peligro de extinción. Sin embargo, no hay garantías de que los murciélagos vayan a entrar y a utilizar el nuevo espacio artificial. Si lo hacen, tres cámaras de vigilancia infrarrojas permitirán a los investigadores vigilar los movimientos de los murciélagos sin molestarlos. Si ningún animal se instala en la cueva, los expertos de The Nature Conservancy podrán utilizarla como laboratorio, por ejemplo, introduciendo algunos murciélagos para probar nuevos fungicidas.

Zuberoa Marcos es bióloga molecular y actualmente trabaja como productora de TV y periodista científica. Escribe de forma regular para Science Today.

The fungi control the ants with mind-altering chemicals, according to Wired Science:

Once infected by spores, the worker ants, normally dedicated to serving the colony, leave the nest, find a small shrub and start climbing. The fungi directs all ants to the same kind of leaf: about 25 centimeters above the ground and at a precise angle to the sun (though the favored angle varies between fungi).

Once the ant arrives at the right leaf, it dies and the fungus takes over. It can produce spores from a single dead ant for up to a year! Wired has some pretty gnarly pictures, if you feel the urge.

The researchers studied these fungi in the wild, not the lab (which has been the trend), and reported their findings last week in the open access, online journal, PLoS One.

In their paper, the authors draw attention to undiscovered, complex, biological interactions in threatened habitats. The four new species all come from the Atlantic Rainforest of Brazil, the most heavily degraded biodiversity hotspot on the planet with ninety-two percent of its original coverage gone. The fungi keep the ant population in check—a tip in the balance could wreak havoc on the ecosystem.

And fungi from this group contribute to both traditional and modern medicine. Again, from Wired:

Organ transplant patients, for example, receive ciclosporin—a drug that suppresses the immune system, reducing the chance the body will reject the new tissue. Chemicals from this same fungal group are also used for antibiotic, anti-malarial and anticancer drugs.

The researchers hope to understand more about this group of fungi before it’s too late. Ants may feel differently…

Image courtesy of PLoS One

Bats are not scary– in fact, what’s not to love about them? Echolocation, mosquito-eaters, they’re mammals and even kind of cute. (Well, maybe not this newly discovered tube-nosed fruit bat.)

But wait, there’s more. Recent research shows that their flight is much more complicated than that of birds and insects. Discover has a great online video demonstrating the process. And bats’ flight could inspire future aerospace technology design, according to the New York Times:

Further study of bat wings could help aerospace engineers develop tiny autonomous airplanes that are as flexible and acrobatic as bats… Today’s aircraft are large and have stiff wings, more similar to birds than to bats.

Other current research shows that bat echolocation goes beyond hunting—it’s also used to identify other bats.

More recent news about bats is sadly very scary. As cold winter weather begins to arrive, scientists are incredibly concerned about the further spread of White Nose Syndrome (WNS), caused by a fungus, that has killed over one million bats since 2006 in the eastern US. Current research suggests that the fungus disrupts the bats’ hibernation, causing them to awaken early, behave oddly, and lose critical fat reserves, resulting in death. One particular species, the little brown myotis, could quickly become extinct in some areas.

Eastern caves are being shut to stop the spread of the fungus. Though it travels from bat to bat, humans likely spread WNS, as well. It is possible that humans brought the syndrome to the US, since the fungus is found in European caves (European bats are not affected by WNS).

Because of the number of insects bats eat each day (more than half their weight), the effects of life without bats could be very dramatic, especially on agriculture. From a recent Popular Science article:

“Without bats, people are going to end up using more pesticides, there will be more water and soil contamination, more human contamination,” [Boston University researcher Tom] Kunz said.

You can help. Send a message to Interior Secretary Ken Salazar to get more funding for scientists studying and hoping to stop WNS. Build your own bat house to help protect your own bat-neighbors (with instructions from Bat Conservation International).

The world would be a very scary place without bats.

Researchers from the University of Montana and the US Army are a step closer to solving the case of colony collapse disorder, or CCD. Publishing in the open access journal PLoS One yesterday, they have determined that the bees are being assaulted by not just one factor, but two.

From the New York Times:

The virus-fungus one-two punch was found in every killed colony the group studied. Neither agent alone seems able to devastate; together, the research suggests, they are 100 percent fatal…

…both the virus and the fungus proliferate in cool, damp weather, and both do their dirty work in the bee gut, suggesting that insect nutrition is somehow compromised.

Now the scientists are racing to determine which attacks the bees first—kind of a chicken and egg scenario between the virus and fungus that are doing the damage.

Sadly, the research is hampered by the fact that the bees fly off and leave the hive to die, scattering the evidence. The scientists are still unsure what causes this action.

The next step for the team is to try and protect the bees. The 80beats blog in Discover describes the work ahead for the University of Montana team:

In the case of Bromenshenk’s team, the scientists’ follow-up task to this week’s study is to isolate the IIV [virus] they found and try to use it in inoculation experiments, hoping that could reveal whether the virus is a key player in causing CCD or just an invader after the fact.

Another article in the New York Times offers why this protection is so important:

Given the source of food they provide, not to mention the honey-based medicines used by the ancient Greeks and Egyptians, among others, bees have saved us — or at least soothed us — as a species over the centuries. Returning the favor only seems fair.

Creative Commons image by Cody Hough

A $17 billion industry in the US, chocolate tantalizes our taste buds, but it can easily fall prey to agricultural disaster. Fungal disease alone can wipe out 80 percent of a crop of cacao trees.

Fear not, chocolate lovers—help is on the way! Last week, scientists and rival candy bar companies announced the sequencing of the cacao tree genome. The U.S. Department of Agriculture hopes that the sequencing will help build stronger trees, better equipped to resist droughts, diseases, and pests that threaten this vital (and delicious) agricultural crop.

The Mars and Hershey companies both led teams of cacao sequencers, in hopes that understanding the genome will also lead to tastier and healthier chocolate.

Chocolate comes from the cacao tree, Theobroma (meaning “food of the gods”) cacao.   The tree seeds are processed into cocoa beans that are the source of cocoa, cocoa butter and chocolate. Num!

Through the 1980s, Brazil supplied most of the world’s cocoa, but a fungus decimated the crops. Today, West Africa grows 70 percent of the world’s crops. Most are managed by small farmers, whose livelihoods could be wiped away instantly if their crops came under attack.

As dark and complicated as chocolate may seem, it’s really not. The cacao genome, according to the New York Times

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.

Mars and their team are currently preparing their genome sequence for publication. Hershey and their team’s sequence is already under review for publication. May the best candy bar win!

Actually, it turns out we’re all winners. Again from the New York Times,

Scientists in both groups say that cocoa farmers, candy companies and chocolate lovers will benefit from having two sequences, of different varieties of cacao, that can be compared.