For example, did you know that male Dayak fruit bats can lactate to feed their young (True according to this article in Nature)? 

Image from “Crime Against Nature”, written and illustrated by Gwenn Seemel.

However, the notion that female spotted hyenas have a “penis” is not entirely accurate. It turns out that high-ranking alpha female hyenas are very aggressive and provide their developing offspring with higher levels of androgen (male sex hormone) than lower-ranking females in late pregnancy. This androgen boost increases the offspring’s chance of survival as it makes them more aggressive at fighting for food and at mating earlier and more often than those receiving less androgen.  The problem is that the high androgen levels damage the mother’s ovaries and cause her clitoris to enlarge (up to 7 inches), thereby resembling a penis. Since the opening of the vaginal canal is at the end of the clitoris, it makes birthing a 2-pound cub through a 2-inch canal dangerous and often fatal for first time mothers. (Source: Michigan State University press release).  

To judge the book for yourself, click here.

Image of atopic dermatitis from www.itchfreepet.com

Dr. Kerstin Lindblad-Toh at Uppsala University (Sweden) who specializes in comparative genomics and Dr. Åke Hedhammar, SLU (Sweden) recently identified a novel gene in German shepherd dogs, PKP-2, that encodes a protein (plakophilin-2) important for regulating proper skin structure and function. This protein was found to be associated with canine atopic dermatitis (i.e. doggy eczema), a condition that affects 3-10% of man’s best friends. Researchers hope that the discovery of this gene relationship may lead to better understanding of, and novel treatments for, eczema in both dogs and the 10-30% of humans who share this condition.

Source:

Uppsala University press release

A Cold War bunker at Loring Air Force Base in Maine that has been converted into a winter haven for bats. Image from: BBC News, USFWS/S. Agius

Scientists in Maine have converted two Cold War bunkers at Loring Air Force Base into winter havens for bats in an effort to protect the animals from the fungus that causes white nose syndrome. What is nice about using a man-made space is that they can actually clean up the area as opposed to trying to kill the fungus in a cave where multiple species of fungi may be affected, thereby disrupting the micro-ecosystem. The winter survival rate is not very high so far, only 9 out of 30 of the animals survived the stress of capture, transport, and captivity. The researchers have added roosts and closed captioning televisions to the bunkers to help study the animals. I hope their efforts at creating man-made safe havens for these bats works as this fungus has killed up to 6.7 million bats to date, and is continuing to spread.

For more information on these bunkers, visit BBC News.

For prior posts on white nose syndrome and bats:

North American Bats Face Possible Endangerment

White Nose Syndrome – Revisited

White Nose Syndrome and Evaporative Water Loss

Does Ketosis Occur During Hibernation?

Clingfish (Gobiesox maeandricus).
Image credit: Thomas Kleinteich

Live Science posted a story recently on the sticking power of clingfish. Northern clingfish, like the one shown in the image above, live in turbulent waters off the Pacific Coast of North America. In order to cling to surfaces, the animals have what are called adhesion discs on their bellies that they use to hold on tightly to various surfaces.

Biologist Adam Summers at the University of Washington has been studying how these fish cling to surfaces. His research team put a variety of sandpaper textures into a tank of water and placed either commercial suction cups or dead clingfish on the sandpaper (to remove any physiological actors leaving just the adhesion discs to study). They then measured the force needed to pull either the cups or the dead fish off the various surfaces. The dead animals clung better to all but the smooth surfaces better than suction cups. The trick, they discovered, were tiny hairs (microvilli) that induce friction and help the adhesion disc stick to rough surfaces.

Summers and colleagues are now trying to create commercial adhesive structures similar to the microvilli on clingfish. They believe this technology will be useful in the advancement of medicine, home and technology.

Source:

Live Science

Alfred Russel Wallace. Image from: NPR, Hulton-Deutsch Collection/Corbis

Darwin is the more famous of the two when it comes to thinking about who came up with the theory of evolution. However, a man named Alfred Russel Wallace co-discovered the theory.

Alfred Wallace died 100 years ago. In honor of his contribution to the theory of evolution, NPR ran a wonderful story about him and his discoveries the other day. Just in case you did not get a chance to hear it, you can either read the transcript or listen to the story here.

Today’s symposia included a session on “Integrative Cardiovascular and Respiratory Physiology of Non-model Organisms” as well as the August Krogh Distinguished Lecture.

This year’s Krogh lecture was given by Dr. Stan Lindstedt from Northern Arizona University. Dr. Lindstedt is arguably best known for publishing work showing that the metabolic rate of an animal is negatively correlated with body mass. In other words, smaller animals have a higher metabolic rate than larger animals. Knowing that relationship could have saved Tusko the elephant from a whopping dose of LSD (1962, prior to the requirement for all studies involving animals to be approved by an institutional animal care and use committee). Dr. Lindstedt related the history of how past researchers at The University of Oklahoma and LJ West from the CIA had known what dose of LSD would cause rage in a cat and just increased the dose to match the body mass of the elephant without taking into consideration that the elephant’s metabolism is much slower than a cat’s. Regardless of the questionable ethics of giving an elephant LSD, the dose was apparently over 5 times the amount that would have been equivalent to what was administered to the cat. As you can see from the headline below, the outcome was not good:

Had the researchers working with Tusko known what Dr. Lindstedt later discovered about scaling, Tusko may have lived through this ridiculous historical experiment. Dr. Lindstedt also presented data that body size is also negatively related to shivering frequency and the frequency of taking strides. Therefore, a mouse has a faster stride than a cow. Could you imagine seeing a cow scurry?

Dr. Lindstedt is also known for studying the mitochondria of species with muscles that are capable of produce really fast contractions: hummingbirds  and rattlesnakes. The mitochondria is a structure within cells that makes energy. In hummingbirds, the mitochondria are specially structured to allow them to make even more energy than a mammal to help support their super-fast wingbeats. For the rattlesnake’s rattle, their muscles release calcium (needed to produce muscle contraction) more efficiently since they have large stores of calcium within the muscle.

More recently, his work has focused on developing the Eccentron. This is a specialized exercise machine that uses eccentric muscle contractions (lengthening) to build strength. You are probably most familiar with this type of exercise from walking downhill. Eccentric muscle contraction can produce high force with very little energy, so his research showed that it was great for elderly people at risk for falling. After gradually training with an Eccentron machine, their fall risk was dramatically reduced.

Image of Eccentron from: www.morphopedics.wikidot.com

 Congratulations Dr. Stan Lindstedt on being this year’s August Krogh lecturer!

Other highlights included: 

 J. Eme, T. Rhen, K. B. Tate, K. Gruchalla, Z. F. Kohl, C. E. Slay, D. A. Crossley II. Univ. of North Texas, Univ. of North Dakota and Univ. of California, Irvine. Dr. Eme, from Univ North Texas, presented work on turtle embryos that were shown to develop larger hearts, increased heart rate, decreased blood pressure and weigh less when developing in an oxygen-poor environment (hypoxic; 10% oxygen) as compared to turtle embryos growing up in a normal oxygen-rich environment (21% oxygen). With the ever-changing natural environment, this is a concern as the developing embryos can be exposed to hypoxic conditions in the wild. Dr. Crossley expanded on this research and talked about the effects of hypoxia exposure on developing alligators. In contrast to the turtle, developing alligators exposed to hypoxia have decreased heart mass, blood pressure, and heart rate compared to those developing in normal oxygen environments. What this means is that the effects of hypoxia on developing embryos is species-specific. Their most recent work on this topic was just published (PMID: 23552497). These findings are of interest especially in areas that raise these animals for food (fried gator or turtle soup, anyone?).

J. U. Meir, W. Jardine, J. York, B. Chua, W. K. Milsom. Harvard Med. Sch. and Univ. of British Columbia. Dr. Meir presented her work on bar-headed geese. She had actually raised the geese from hatching so they would imprint on her. She showed some really neat photos riding a scooter alongside the birds as they learned to fly next to her. The whole point of these exercises was to train the birds to eventually fly in a wind tunnel and to get them used to wearing a mask that could be used to manipulate the oxygen concentrations the geese were breathing. The bar-headed geese are spectacular flyers and are probably best known for flying over Mount Everest. Extreme hypoxic conditions, to say the least! Her research is really novel in that she was able to measure the amount of oxygen in the bird’s blood and their temperature during flight! Her preliminary analyses of the data suggest that the tissues of the birds are able to adequately extract the much-needed oxygen from the blood very well even while breathing in oxygen concentrations that mimic ~5500 m (10.5% oxygen) or 9000 m above sea level (7% oxygen).

You can watch the development of her research here:

What a great day for comparative physiology!

Another exciting day for Comparative Physiology! I just got back to my hotel after the wonderful dinner meeting overlooking the Harbor.

Of course, the research was exciting too

Here are the highlights from today’s sessions:

Heinrich E, Bradley T. Univ California, Irvine I learned a lot about the insect tracheal system this morning. Insects do not have continuous gas exchange with environment like we do. Rather, gas exchange is discontinuous and involves valves, called spiracles:

Diagram of how insects breathe from www.breatheornot.wordpress.com

When carbon dioxide levels increase, the spiracles open to get rid of the carbon dioxide. When oxygen levels decline, it causes the spiracles to flutter to promote oxygen uptake.

Slay CE, Enok S, Wang T, Hicks JW. Univ California, Irvine and Aarhus University, Denmark. Burmese pythons  do not eat very often, to the relief of many prey. After eating a meal that is often ~25% of its body mass, a python will develop an enlarged heart. The increase in heart size is related to an increase in metabolism, heart rate and cardiac output.

Jackson DC, Brown University. A turtle’s shell is not just for decoration. The bony shell of a turtle helps to prevent the animal’s blood from becoming acidic. This is especially important for species that can tolerate conditions devoid of oxygen (anoxic) that would promote acidity. The reigning champion of anoxia tolerance is the painted turtle. In fact, Dr. Jackson reported that two-thirds of the lactic acid produced by the animal is buffered by the shell.

The Comparative and Evolutionary Physiology section held their Scholander Poster competition for young comparative physiologists today! It was exciting to see all of the students present their work.

Here are some of the highlights:

Raffaele Pilla, Dominic P, D’Agostino, Carol S. Landon, and Jay B. Dean from Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL. These researchers demonstrated that a ketone body, often thought of as waste products resulting from the use of fats for energy, can have protective effects against seizures caused by exposure to hyperbaric oxgyen.

Jose A Viscarra, Daniel E Crocker, and Rudy M Ortiz from the University of California, Merced (JAV and RMO) and Sonoma State University, Rohnert Park, CA (DEC) were studying the effects of long-term fasting in Northern elephant seal pups that normally fast for 2-3 months after they wean. What they found was that the animals actually became resistant to the blood sugar lowering effects of insulin during this long term fast. In other words, they became more like a person with type 2 diabetes. 

PonTi Tsou, Geetha Koneru, Luiz Finatti, Kara Bobka, James Frisbie, David L. Goldstein. Wright State University, Dayton, OH discovered that freeze tolerant Gray tree frogs (Hyla chrysoscelis) actually increase the ability for glycerol (a cryoprotectant) to be secreted by the liver cells in order to protect the animal’s tissues during freezing.

As always, the opening ceremony for the American Physiological Society at the Experimental Biology meeting was awesome! The food was probably the best I have had at these meetings, which along with the fun band, probably explains why it was jam-packed with Physiologists eager to kick-start this meeting.

I am looking forward to the Scholander poster session tomorrow. This poster session is sponsored by the Comparative and Evolutionary Physiology section of The American Physiological Society. It is a competition in which trainees present their research in the hopes of receiving a travel award to help cover some of the costs of their trip to Boston. Other travel awards are sponsored by Novo Nordisk. I am looking forward to sharing some of the exciting research with you tomorrow! Stay tuned…

You can follow the twitter feed as well:

#EB2013

@DrDoScienceBlog

Image of a Giant African land snail from a Florida Department of Agriculture Division of Plant Industry handout.

Giant African land snails, like the one pictured above, are reportedly “one of the world’s most destructive invasive species” as they not only consume over 500 plant species, they can actually eat stucco (apparently a good source of calcium). Therefore, I am sure you can imagine the damage they are causing in South Florida where they can grow as large as a rat. Since 2011 when the snail was first seen, more than 117,000 have been captured in Miami-Dade County.

More problemmatic, with the growing infestation, is that the snails can carry a parasitic worm that can lead to a type of meningitis in humans, although there have been no confirmed cases in the United States.

Source:

Reuters