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  • October 28, 2010
  • 05:43 AM
  • 845 views

Sons of the conquerers: the story of India?

by Razib Khan in Gene Expression


The past ten years has obviously been very active in the area of human genomics, but in the domain of South Asian genetic relationships in a world wide context it has seen veritable revolutions and counter-revolutions. The final outlines are still to be determined. In the mid-1990s the conventional wisdom was that South Asians were [...]... Read more »

Gyaneshwer Chaubey, Mait Metspalu, Ying Choi, Reedik Mägi, Irene Gallego Romero, Pedro Soares, Mannis van Oven, Doron M. Behar, Siiri Rootsi, Georgi Hudjashov.... (2010) Population Genetic Structure in Indian Austroasiatic speakers: The Role of Landscape Barriers and Sex-specific Admixture. Mol Biol Evol. info:/10.1093/molbev/msq288

  • October 28, 2010
  • 05:24 AM
  • 1,591 views

better protein pharmacokinetics with a tail

by 96well in Reportergene

A combined protein/polymer-engineering approach prolongs protein circulation and enhance drug accumulation in tumours.
Consider insulin and you will have no doubts that a protein could be a drug. As proteins are coded by a corresponding DNA, the application of recombinant DNA has been largely exploited in clinics to provide patients with therapeutic 'recombinant' proteins. Among the advantages of owing a potential pharmacon on a plasmid, and growing such a marketable molecule in cell cultures, is the possibility to engineer the drug protein to ameliorate its efficacy. Therefore, one could change few amino-acids to improve some binding activities, combine two protein moieties to obtain a new double-edged drug and so on, depending on the creativity of the medicinal chemist synthetic biologist.
Some proteins like interferon-α2a are effective against cancer, but are toxic also for other cells. Therefore, some engineering could maximize protein delivery to tumours while minimizing its bioavailibility to other organs. Gao and colleagues from Duke University, reasoned about a potential trick to do this job. The microvasculature of tumours is leaky compared with that of most normal tissues, therefore a drug complexed with a 'bulk' polymer would leak slowly from healthy microvessels, but quickly from the microvessels supplying tumours. As a proof of concept, they injected a normal green fluorescent protein in the mouse tail vein and monitored its accumulation in the tumour. Then, compared it with a second GFP in which its C-terminus was used as a docking site to grow a long polymer tail.

A post-translational protein splicing strategy was used to install a polymerization initiator at the C terminus, followed by in situ living methacrylate polymerization. The resulting 20-nm polymer–protein conjugate did indeed experience longer circulation times, and it leaked into tumours in mice 50 times more efficiently than the unmodified protein. In conclusion, the pharmacokinetic profile of therapeutic proteins could be significantly ameliorated by protein engineering.
Synthetic biology has been previously blamed to be nothing but a cool divertimento for junior scientists less serious than the senior medicinal chemist. The work of Gao and colleagues indeed demonstrate that plasmid juggling can provide us with better drugs, lets play the game again and again.
---/ reference /--- --- ---
Gao, W., Liu, W., Christensen, T., Zalutsky, M., & Chilkoti, A. (2010). In situ growth of a PEG-like polymer from the C terminus of an intein fusion protein improves pharmacokinetics and tumor accumulation Proceedings of the National Academy of Sciences, 107 (38), 16432-16437 DOI: 10.1073/pnas.1006044107

... Read more »

  • October 28, 2010
  • 01:50 AM
  • 1,573 views

AquAdvantage update

by Anastasia Bodnar in Biofortified

In Risk assessment and mitigation of AquAdvantage salmon I discussed exactly what Aqua Bounty was asking permission from the FDA to do, as well as the environmental, animal welfare, and human health concerns associated with the AquAvantage fish in comparison to non-transgenic farmed salmon. The Center for Food Safety has a “new” document to bring to the discussion: an opinion (pdf) written by the National Marine Fisheries Service regarding a U.S. Army Corps of Engineers proposal about Continue reading...... Read more »

L. Fredrik Sundstro ̈m, Wendy E. Tymchuk, Mare Lo ̃hmus, & Robert H. Devlin. (2009) Sustained predation effects of hatchery-reared transgenic coho salmon Oncorhynchus kisutch in semi-natural environments. Journal of Applied Ecology, 762-769. info:/10.1111/j.1365-2664.2009.01668.x

  • October 28, 2010
  • 12:01 AM
  • 644 views

What do we do with forecasts of the future?

by Noam Ross in Noam Ross

Via Garry Peterson  I discovered this post by Simon Donner about forecasts of this year's massive coral bleaching event in the Carribbean.
Donner and colleagues published a paper in PNAS in 2007 in which they calculated that heat waves that cause massive coral bleaching, like a previous event in 2005, had gone from being 1-in-1000-year events to a probability of once every 10-50 years during the 1990s, and by the 2030s will occur every 1-2 years. This year's event, says Donner, is another fingerprint of human-driven climate change:
Keep in mind the predictions. This is what the scientific community predicted was likely to happen. An event which we calculated would be a once in a millennium occurrence without human impact on the climate, happened again five years later.
Donner's post led me to NOAA's Coral Reef Watch Program, which makes near-term forecasts of sea temperatures.  Our knowledge of  ocean climate allows us to make predictions several months out.  It turns out NOAA warned of this season's bleaching at the beginning of June.
We are getting better at forecasting the future. As we learn more, we will get better at both Donner's type of prediction (changes in long-term frequencies), and NOAA's (changes in short-term likelihood).
My question is: Do we know enough to use this information?  I was actually surprised to learn from NOAA's site the extent of short-term responses available in the case of corals.  Reefs can be shaded to prevent heat stress, and if possible certain stressors, like fishing or nearby pollution discharges, can be suspended.   But such actions are probably only marginally effective, and can only be carried out in a few systems. Besides minimizing the extent of climate change, building resilience into coral reefs and the social-ecological systems in which they are embedded will be more important in the long run.  
My own work, which I hope to write about here soon, involves similar problems in forests - we know that drought-driven die-offs will increase in the future, and (I hope) we may be able to predict them in the near term.   But how can we use our ability to forecast to build more resilient systems?
Lesser, M. (2007). Coral reef bleaching and global climate change: Can corals survive the next century? Proceedings of the National Academy of Sciences, 104 (13), 5259-5260 DOI: 10.1073/pnas.0700910104... Read more »

  • October 27, 2010
  • 11:18 PM
  • 609 views

New papers about developmental stochasticity, species delimitation, and functional genomic neighborhoods.

by Victor Hanson-Smith in Evolution, Development, and Genomics

posted by Victor Hanson-Smith Here are three articles—published this week!—that might be relevant to your interests. 1. Stochasticity versus determinism in development: a false dichotomy? Magdalena Zernicka-Goetz, et al., Nature Reviews Genetics, November 2010 The developmental trajectory (from embryo to death) … Continue reading →... Read more »

  • October 27, 2010
  • 10:53 PM
  • 508 views

Big data

by Michelle Greene in NeurRealism

It took 13 years to crunch through the 3 billion base pairs that make up the human genome. These data have been violating our assumptions ever since. My introductory biology textbook, published in 1996, speculates that there might be up to 100,000 genes in the genome. It turns out there are a lot less: about 20,000-30,000 by more recent estimates. The Human Genome Project sequenced only a few individuals, and combined all into one genome. However, many of the big questions we have about genetics concerns the differences between individuals. We are starting to get answers to these questions. In today’s issue of Nature, a paper was published from the 1000 Genome Project, a massive collaborative effort from three continents that is designed to describe and explain the variance between individual’s genomes.

In this work, several types of variance were investigated as independent pilot studies. First, patterns between several mother-father-child trios were examined. Second, a group of 179 people had their whole genomes sequences. Last, more sparse sequencing was done on ~700 people from very diverse genetic backgrounds. While this paper is mostly serving as a progress report, and proof of concept, one very interesting bit is the finding that on average, any given person carries 50-100 gene variants that have been associated with higher risk of illness. This is very reminiscent of last week’s PNAS article showing that possessing such “risky” alleles does not decrease your lifespan to a statistically significant degree. ... Read more »

Durbin, R., Altshuler, D., Durbin, R., Abecasis, G., Bentley, D., Chakravarti, A., Clark, A., Collins, F., De La Vega, F., Donnelly, P.... (2010) A map of human genome variation from population-scale sequencing. Nature, 467(7319), 1061-1073. DOI: 10.1038/nature09534  

  • October 27, 2010
  • 09:55 PM
  • 1,403 views

Oddest photo accompanying 1000 Genomes news

by Mary in OpenHelix

Right now on the Science section of The Guardian, I find this [photo of bikini clad concert goer?]:

Er, what?
OK–but the real news is in Nature today. With an appropriate cover image.

Anyway, I’ve just barely had a chance to look over the paper. I often find the supplemental info is what I need (methods, software, etc), and that’s almost another hundred pages for one of them. So I don’t have any real conclusions yet.  Some of it was familiar to folks who may have been using the 1000 Genomes site already. We did a Tip of the Week on it recently and you can check that out to learn about the web site and the browser.
There’s also a Nature News piece that speaks to some of the highlights of the work. There was another interesting item in Nature about the number of human genomes we’ve got in the bag, and how many we should expect in the quite near term:  Human genome: Genomes by the thousand Wowsa. I’m trying to remember to call it the Data Bonanza at the folks at Beyond the Genome were trying to encourage, rather than one of the scary and more negative terms. But I’m daunted. Enthused. But daunted.
But it’s the topic-of-the-day in the science twittersphere. Figured I’d mention it.
As a reminder–if you want to use 1000 Genomes data and you’ll be at ASHG next week, there’s a tutorial/workshop you can sign up for.  Also, people have been asking questions about how to use the data at the BioStar discussion site (see the 1000 Genomes tag).  Another hot tip about ASHG is Daniel MacArthur tweeted today:
For those interested in the 1000G “gene-killing polymorphisms” story, I’ll be presenting an update next Thursday at ASHG.
And yes, I’m sorry the reference is longer than this post.
... Read more »

Durbin, R., Altshuler, D., Durbin, R., Abecasis, G., Bentley, D., Chakravarti, A., Clark, A., Collins, F., De La Vega, F., Donnelly, P.... (2010) A map of human genome variation from population-scale sequencing. Nature, 467(7319), 1061-1073. DOI: 10.1038/nature09534  

  • October 27, 2010
  • 04:18 PM
  • 1,379 views

But did you correct your results using a dead salmon?

by Iddo Friedberg in Byte Size Biology

fMRI tests are very popular. Why should they not be? Take someone, stick them in an MRI, show them a picture of their mother-in-law, see which bits of their brain light up (get more blood, hence are more active) and voila! You’re in the New York Times science supplement under the title “Scientists discover brain region responsible for unmitigated rage.” (Any resemblance to any actual mother-in-law, living or dead, is purely coincidental.) fMRI is a great tool for mapping cognitive processes into specific areas of the brain. It is our tool to connect between mind and brain, so to speak.... Read more »

Craig M. Bennett, Abigail A. Baird, Michael B. Miller, & George L. Wolford. (2010) Neural Correlates of Interspecies Perspective Taking in the Post-Mortem Atlantic Salmon: An Argument For Proper Multiple Comparisons Correction. JSUR, 1(1), 1-5. info:other/http://jsur.org/v1n1p1

  • October 27, 2010
  • 03:04 PM
  • 1,139 views

The grand diversity of marine phytoplankton species: focusing from space

by Hannah Waters in Sleeping with the Fishes

In a recent email exchange with a (skeptically) wonderful blogger about why we are interested in what we are and where past/current biases lie, I wrote that I “grew up wanting to look at the planet from space.”  This is true in multiple senses: my drive to seek patterns in collected studies and data, and also my interest in large-scale ecology generally. But, of course, we can actually look at the planet from space!  And collect data at the same time!  Via the wonder of SATELLITES!  In 1997, NASA began launching satellites into earth’s orbit as part of its Earth Observing System in its Earth Science Enterprise program.  These satellites collect data on a number of global environmental factors including ice cover, cloud cover, chlorophyll concentration, and sea surface temperature mainly using radar and surface coloration. NASA earth observatories. These are satellites in orbit Chlorophyll concentration has been of particular interest lately because it is used as a proxy for photosynthesis, and thus carbon uptake and oxygen release.  In the ocean, these data are collected by color sensors such as SeaWiFS, OCTS and MODIS.  Since chlorophyll is green, the satellites essentially collect ocean color data and then remove the regional background color of the water, resulting in the amount of green, indicating the concentration of chlorophyll-a. For . . . → Read More: The grand diversity of marine phytoplankton species: focusing from space... Read more »

d'Ovidio, F., De Monte, S., Alvain, S., Dandonneau, Y., & Levy, M. (2010) Fluid dynamical niches of phytoplankton types. Proceedings of the National Academy of Sciences, 107(43), 18366-18370. DOI: 10.1073/pnas.1004620107  

  • October 27, 2010
  • 02:57 PM
  • 1,307 views

Where did all these primates come from? – Fossil teeth may hint at an Asian origin for anthropoid primates

by Laelaps in Laelaps

Where did anthropoid primates come from? This question has not been an easy one to answer. Since the early days of paleontology various experts have proposed a slew of scenarios for the origins of the primate group which today contains monkeys and apes (including us), with different experts favoring various combination of places, times, and [...]... Read more »

Bajpai, S., Kay, R., Williams, B., Das, D., Kapur, V., & Tiwari, B. (2008) The oldest Asian record of Anthropoidea. Proceedings of the National Academy of Sciences, 105(32), 11093-11098. DOI: 10.1073/pnas.0804159105  

K. Christopher Beard. (2006) Mammalian Biogeography and Anthropoid Origins . Primate Biogeography, 439-467. info:/10.1007/0-387-31710-4_15

Beard, K., Marivaux, L., Chaimanee, Y., Jaeger, J., Marandat, B., Tafforeau, P., Soe, A., Tun, S., & Kyaw, A. (2009) A new primate from the Eocene Pondaung Formation of Myanmar and the monophyly of Burmese amphipithecids. Proceedings of the Royal Society B: Biological Sciences, 276(1671), 3285-3294. DOI: 10.1098/rspb.2009.0836  

Jaeger, J., Beard, K., Chaimanee, Y., Salem, M., Benammi, M., Hlal, O., Coster, P., Bilal, A., Duringer, P., Schuster, M.... (2010) Late middle Eocene epoch of Libya yields earliest known radiation of African anthropoids. Nature, 467(7319), 1095-1098. DOI: 10.1038/nature09425  

  • October 27, 2010
  • 02:35 PM
  • 423 views

Mt. Moult

by Journal Watch Online in Journal Watch Online

Some people climb tall mountains because they are there. In Nicaragua, a tiny hummingbird apparently heads to the summit to grow a new crop of feathers. The unusual vertical moulting migration highlights the challenge of protecting species that may travel far and high to survive.
The blue-tailed hummingbird (Amazilia cyanura) is a common but little-studied […] Read More »... Read more »

  • October 27, 2010
  • 02:30 PM
  • 1,636 views

Functional selectivity: Nature's Bach concerto

by The Curious Wavefunction in The Curious Wavefunction

One of the great things about Bach’s organ music is how changes of a single note in a whole pattern can have rather dramatic effects on the sound. A unique and potentially very important similar phenomenon has been discovered recently in the area of GPCR research.The understanding of the basic process by which GPCRs transmit signals from the cell exterior to the interior has seen remarkable advances in the last three decades, but much still remains to be deciphered. Our knowledge of signaling responses until now hinged on the action of agonists and antagonists. Central to this knowledge was the concept of ‘intrinsic efficacy’; according to this concept, there was no difference between two full agonists for instance, and both of them would produce the same response irrespective of the situation.But this understanding failed to explain some observations. For instance, a full agonist would function as a partial agonist and even as an inverse agonist under different circumstances. Several such observations, especially in the context of GPCRs involved in neurotransmission, have forced a re-evaluation of the concept of intrinsic efficacy and led to an integrated formulation of a fascinating concept called ‘functional selectivity’.So what is functional selectivity? It is the phenomenon by which the same kind of ligand (agonist, antagonist etc.) can modulate different signaling pathways activated by a single GPCR, leading to different physiological responses. Functional selectivity thus opens up a whole new method of modifying GPCR signaling in complex ways. It comprises a new layer of complexity and control that biological systems enforce at the molecular level to engage in complex signaling and homeostasis. Functional selectivity can allow the ‘tuning’ of ligands on a continuum scale of properties, from agonism to inverse agonism. In addition it can tightly regulate the strength of the particular property. It is what allows GPCRs to function as rheostats rather than as binary switches and allows them to exercise a fine layer of biological control and discrimination.Functional selectivity is not just of academic interest. It can have clinical significance. Probably most tantalizingly, it may be one of the holy grails of pharmacology that allows us to separate the beneficial and harmful effects of a drug, leading to Paul Ehrlich’s ‘magic bullet’. Until now, side-effects have been predominantly thought to result from the lack of subtype-specificity of drugs. For instance, morphine’s side effects are thought to result from its activation of the μ-opioid receptor. But functional selectivity could provide a totally new avenue for explaining and possibly mitigating side-effects of drugs. For instance, consider the dopamine receptor agonist ropinirole, used in the treatment of Parkinson’s disease. There are several D-receptor agonists and just like them ropinirole interacts with several receptor subtypes. But unlike many of these, ropinirole does not demonstrate the dangerous side-effect named valvulopathy, a weakening of the heart valves that makes them stiff and inflamed. This can be a potentially life-threatening condition that seems to be facilitated by several dopamine agonists, but not ropinirole. The cause seems to be becoming clear only now; ropinirole is a functionally selective ligand that activates a certain pattern of second messenger pathways that is different from those activated by other agonists. Somehow this pattern of pathways is responsible for reduced valvulopathy.Let’s go back to the organ/piano analogy to gauge the significance of such control. The sound produced by a piano depends on two variables- the exact identities of the keys pressed, and the intensity (how hard or softly you press them). The second variable can be as important as the first since a pressing a key particularly hard can drown out other notes and influence the very nature of the sound. The analogy to functional selectivity would be in looking at the keys themselves as different signaling pathways and the intensity of the notes as the strength of the pathways. Now, if one ligand binding to a single GPCR is able to activate a specific combination of these pathways, each with its own strengths, think of the permutations and combinations you could get from a set of even a dozen pathways- an astonishing number. Thus, functional selectivity could be the key that unlocks the puzzle of how one ligand can put into motion such a complex set of signaling events and physiological responses. One ligand- one receptor- several pathways with differing strengths. An added variable is the concentration of certain second messengers in a particular environment or cell type, which could add even more combinations. This picture could go a long way toward explaining how we can get such complex signaling in the brain from just a few ligands like dopamine, serotonin and histamine. And as described above, it also provides a fascinating direction - along with control of subtype selectivity (a much more well known and accepted cause) - for developing therapies that demonstrate all the good stuff without the bad stuff.The basic foundation of functional selectivity is as tantalizing. Whatever the reasons for the phenomenon, the proximal cause for it has to concern the stabilization of different protein conformations by the same kind of ligands. Unravel these protein conformations and you would make significant inroads into unraveling functional selectivity. If you come to think of it, this principle is not too different from the current model of conformational selection used in explaining the action of agonists and antagonists in general, which involves the stabilization of certain conformations by specific molecules.Nature never ceases to amaze. As we plumb its mysteries further, it reveals deeper, more subtle and finer layers of control and discrimination that allows it to generate profound complexity starting from some relatively simple events like the binding of a disarmingly simple molecule like adrenaline to a protein. And combined with the action of several proteins, the concerto turns into a symphony. We have been privileged to be in the audience.Mailman, R., & Murthy, V. (2010). Ligand functional selectivity advances our understanding of drug mechanisms and drug discovery Neuropsychopharmacology, 35 (1), 345-346 DOI: 10.1038/npp.2009.117Kelly, E., Bailey, C., & Henderson, G. (2009). Agonist-selective mechanisms of GPCR desensitization British Journal of Pharmacology, 153 (S1) DOI: 10.1038/sj.bjp.0707604... Read more »

  • October 27, 2010
  • 02:15 PM
  • 1,531 views

The evolution of novelty through subtle tinkering

by Lucas in thoughtomics







The genealogies of European royalty are genuinely terrifying in their complexity. No matter which history book you open, someone is always marrying some cousin of the third degree. To give you an idea: there are at least 4,010 different lines of descent from William the Conqueror to Prince William. Go figure.
Protein families might rival European [...]... Read more »

  • October 27, 2010
  • 01:29 PM
  • 1,343 views

New Fossil Anemone Reveals Innard Secrets

by Kevin Zelnio in Deep Sea News

Continuing its trend as one of the top destinations for out-of-this-world fossil finds, China is yielding yet another piece to the evolutionary jigsaw puzzle. In a recent PLoS One article, Han and colleagues report the findings of a new squishy sea anemone from the Lower Cambrian. The new find lends support to genetic data that suggests . . . → Read More: New Fossil Anemone Reveals Innard Secrets... Read more »

Han, J., Kubota, S., Uchida, H., Stanley, G., Yao, X., Shu, D., Li, Y., & Yasui, K. (2010) Tiny Sea Anemone from the Lower Cambrian of China. PLoS ONE, 5(10). DOI: 10.1371/journal.pone.0013276  

  • October 27, 2010
  • 12:08 PM
  • 1,978 views

Chemistry of the Great Big Blue: Pharmaceuticals

by Bluegrass Blue Crab in Southern Fried Science

Caffeinated crabs, anti-depressed dolphins, and feminized fish, oh, my! Can you imagine what would happen if sea creatures had access to your medicine cabinet? Well, they do. Pharmaceuticals from humans make their way into the ecosystem either through excretion into urine or by people disposing of old medications down the toilet. The first of these sources [...]... Read more »

E. R. Peele, F. L. Singleton, J. W. Deming, B. Cavari and R. R. Colwell. (1981) Effects of Pharmaceutical Wastes on Microbial Populations in Surface Waters at the Puerto Rico Dump Site in the Atlantic Ocean . Applied Environmental Microbiology, 41(4). info:/

  • October 27, 2010
  • 12:00 PM
  • 430 views

Coconut Crab

by beredim in Strange Animals

The coconut crab, Birgus latro, is the largest, land-living arthropod in the world. ... Read more »

  • October 27, 2010
  • 10:13 AM
  • 554 views

Pouches, pockets and sacs in the heads, necks and chests of mammals, part IV: reindeer and a whole slew of others [Tetrapod Zoology]

by Darren Naish none@example.com in Food Matters



I really must get this series on pouches, sacs and pockets finished. Last time, we looked at baleen whales (and then I got distracted by Caperea): in these animals, a large, inflatable laryngeal sac is used in producing loud, resonating noises (though roles in gas storage or the mechanics of exhalation have also been suggested).



Another ventrally located laryngeal sac is present in the Reindeer Rangifer tarandus [photo above, by Karen Laubenstein, from wikipedia, shows an Alaskan reindeer with wonderfully elaborate antlers]. The sac originates from the trachea close to the epiglottis, is present in both sexes (though is much larger in males, reaching 4000 cubic cm when inflated), and can extend asymmetrically either along the left or right side of the neck (Frey et al. 2007). Read the rest of this post... | Read the comments on this post...

... Read more »

Frey, R., Gebler, A., Fritsch, G., Nygrén, K., & Weissengruber, G. E. (2007) Nordic rattle - the hoarse phonation and the inflatable laryngeal air sac of reindeer (Rangifer tarandus). Journal of Anatomy, 131-159. info:/

  • October 27, 2010
  • 10:07 AM
  • 711 views

Tracking the Emergence of Birds

by Brian Switek in Dinosaur Tracking

Since the description of the fuzzy-feathered dinosaur Sinosauropteryx in 1996, paleontologists have been inundated with a still-flowing flood of fossil evidence confirming that birds are living dinosaurs. More than that, many of the characteristics we once thought were unique to birds—from air-sacs to infestations of peculiar microorganisms—were common among dinosaurs, too, and every year it [...]... Read more »

  • October 27, 2010
  • 09:48 AM
  • 640 views

Having Many Sisters Makes a Male More Efficient When Mating

by APS Daily Observations in Daily Observations


Growing up with lots of sisters makes a male less manly, but apparently more efficient when copulating—in rats, at least! A new study published in Psychological Science finds that for ... Read more »

  • October 27, 2010
  • 09:26 AM
  • 1,023 views

Pouches, pockets and sacs in the heads, necks and chests of mammals, part IV: reindeer and a whole slew of others

by Darren Naish in Tetrapod Zoology



I really must get this series on pouches, sacs and pockets finished. Last time, we looked at baleen whales (and then I got distracted by Caperea): in these animals, a large, inflatable laryngeal sac is used in producing loud, resonating noises (though roles in gas storage or the mechanics of exhalation have also been suggested).



Another ventrally located laryngeal sac is present in the Reindeer Rangifer tarandus [photo above, by Karen Laubenstein, from wikipedia, shows an Alaskan reindeer with wonderfully elaborate antlers]. The sac originates from the trachea close to the epiglottis, is present in both sexes (though is much larger in males, reaching 4000 cubic cm when inflated), and can extend asymmetrically either along the left or right side of the neck (Frey et al. 2007). Read the rest of this post... | Read the comments on this post...... Read more »

Frey, R., Gebler, A., Fritsch, G., Nygrén, K., & Weissengruber, G. E. (2007) Nordic rattle - the hoarse phonation and the inflatable laryngeal air sac of reindeer (Rangifer tarandus). Journal of Anatomy, 131-159. info:/

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