WBEZ | dinosaur http://www.wbez.org/tags/dinosaur Latest from WBEZ Chicago Public Radio en Clever Apes: Cooking up a dino-chicken http://www.wbez.org/blog/clever-apes/2012-03-07/clever-apes-cooking-dino-chicken-97060 <img typeof="foaf:Image" src="http://llnw.wbez.org//blog/photo/2012-March/2012-03-07/StevenW.jpg" alt="" /><p><p><img alt="The chickenosaurus could once again roam the earth, if Jack Horner has his way. " class="caption" height="199" src="http://llnw.wbez.org/blog/insert-image/2012-March/2012-03-07/John Flinchbaugh.jpg" title="The chickenosaurus could once again roam the earth, if Jack Horner has his way. (Flickr/John Flinchbaugh)" width="600"></p><p><strong><em>We bring you a guest post today from Faraz Hussain, who studies biochemistry at Illinois Institute of Technology. Faraz is a student of Joseph Orgel, the biologist researching preserved dinosaur tissue whom we profiled in the latest episode of Clever Apes. Here, Faraz introduces us to a completely different way of bridging the eons to bring dinosaurs into the present day. – Gabriel Spitzer</em></strong></p><p>Dinosaurs’ 180 million-odd year reign may be considered a lively old romp by most, but some clever apes would prefer to study these fossils in the flesh. One particular suborder, the theropods, never really went extinct at all. The birds that descended from them are the nearest living relatives today of both raptors and tyrannosaurs—perhaps none more so than the humble hen. Paleontologist Jack Horner, one of the most vocal exponents of avian dinosaurs being all around us, would rather that hens' more imposing ancestors had not evolutionarily "chickened out" in the first place.</p><p>Instead of messing about with amber-encased mosquitoes gorged on dino-DNA and playing fill-in-the-blanks with frog and bird genomes à la <a href="http://www.ucmp.berkeley.edu/diapsids/buzz/popular.html"><em>Jurassic Park</em></a>, Horner has been rallying his <a href="http://serc.carleton.edu/research_education/paleontology/hottopics.html">paleontologist pals and evolutionary developmental biologists</a> to try a fresh tack on resurrecting a dinosaur: He wants to reverse-engineer a chickenosaurus. Hey, why start from scratch when you already have a fully-formed dinosaur in need of just a few minor genetic modifications? What follows is not your grandma's stuffed chicken recipe:</p><p><strong>Chicken fingers:</strong></p><p>While birds may have opted for wings instead of claws, both the T. rex and the chicken have <a href="http://www.ncbi.nlm.nih.gov/pubmed/20564580">only three digits</a> at the end of each. In birds, however, these fingers have fused together. Hans Larsson at McGill University's Redpath Museum is looking for ways to short-circuit the genetic pathway responsible for this process in the chicken's embryonic stage and allowing the digits to separate so that, instead of those delicious wings, it ends up with far deadlier talons instead.</p><p><strong>Rump:</strong></p><p>A chicken has only a handful of vertebrae at the end of its spine that fuse to form what passes for its tail. In 2007, Larsson observed a tail in a developing chick embryo that had 16, although by the time it hatched these had dwindled to five. Turn off the genetic mechanism that triggers the breakdown and absorption of the tail, and voilà—you're well on your way to the 40 or so vertebrae found in some of the heftiest hindquarters ever: the T. rex tail.</p><p><img alt="Some tweaks to a chickens gene expression might yield a latter-day dinosaur. (Fl" class="caption" src="http://llnw.wbez.org/blog/insert-image/2012-March/2012-03-07/StevenW.jpg" style="width: 350px; height: 263px; margin: 10px; float: right;" title="Some tweaks to a chicken's gene expression might yield a latter-day dinosaur. (Flickr/StevenW)"><strong>Teeth:</strong></p><p>Matthew Harris discovered the <a href="http://www.paleogenetics.com/articles/archosaurianteethchicken.pdf">rudiments of teeth</a> on a frankenchicken embryo called the talpid2 usually known for its polydactyl fingers. While a far cry from the toothy old tyrannosaur grin that we know and love—the genome of a chicken doesn’t contain genes coding for enamel, nor can they produce dentin, which made up the bulk of those formidable fangs—it’s finally a fighting chance for poultry to bite back!</p><p><strong>Chicken feet:</strong></p><p>The scaly skin covering chicken feet is the closest approximation we have to dinosaur dermis. Engineered so that it would be shorn of its feathers from birth and covered in this leathery skin, the one issue that would remain to be settled is whether you prefer your dinosaurs purple or green. The only real clues we have when it comes to coloration are <a href="http://todd.jackman.villanova.edu/DinosaurColors.pdf">possible hints about the plumage of the turkey-sized <em>Sinosauropteryx</em></a>.</p><p><strong>Drumsticks:</strong></p><p>Another gimme! Instead of picking your garden variety Rhode Island Red, which like most birds of its feather, <a href="http://onlinelibrary.wiley.com/doi/10.1002/ar.20963/full">is restricted to a horizontal femoral posture</a>, start out with a heartier cousin like the Philippine gamecock instead, which has an upright femur robust enough to carry the weight of its eventual dino-tail.</p><p><strong>Beak:</strong></p><p>Arkhat Abzhanov <a href="http://www.oeb.harvard.edu/faculty/abzhanov/pubs/Abzhanov_et_al_2007_Congenital_Anomalies.pdf">found that two signaling proteins</a>—Fibroblast growth factor 8 and the creatively named Sonic hedgehog—mediate the fusion of different segments making up a bird’s jawbone to form what ends up as the core of its beak. In alligators, which are among the <a href="http://www.washington.edu/news/articles/china-fossil-shows-bird-crocodile-family-trees-split-earlier-than-thought">closest living relatives of birds</a>, these bones remain separate, giving rise to their characteristic snouts. Using beads of proteins to block the expression of these signaling molecules at the appropriate stage of embryonic development, Abzhanov produced chicks with alligator-like snouts. Ultimately, he would like to revert a chick back to the state of its <em>Maniraptoran</em> forebears, but he says that ethical considerations currently prevent him from allowing any of his snouted chickens to hatch.</p><p>If the story of the snout rings a bell, see the required ingredients for chicken fingers above. The mechanisms triggering beak and wing formation are not too different; what worked for the beak may apply to winding back the clock on the wings, as well. Interestingly, even some of the biologists who are pioneering these approaches are dubious about whether they can be applied to a project of such outsized proportions, but Horner is not content to see these fantastic techniques being used for anything less than the creation of a poultrified protosaur—the first of its kind.</p><p><strong><em>Faraz Hussain is a biochem major at IIT and a budding science writer. </em></strong></p></p> Wed, 07 Mar 2012 20:55:00 -0600 http://www.wbez.org/blog/clever-apes/2012-03-07/clever-apes-cooking-dino-chicken-97060 Clever Apes #27: Breaking the fossil record http://www.wbez.org/blog/clever-apes/2012-03-08/clever-apes-27-breaking-fossil-record-96971 <img typeof="foaf:Image" src="http://llnw.wbez.org//blog/photo/2012-March/2012-03-07/Orgel2.JPG" alt="" /><p><p><img alt="Joseph Orgel holds his sample of T. rex tissue. (WBEZ/Michael De Bonis)" class="caption" height="450" src="http://llnw.wbez.org/blog/insert-image/2012-March/2012-03-07/Orgel2.JPG" title="Joseph Orgel holds his sample of T. rex tissue. (WBEZ/Michael De Bonis)" width="600"></p><p>Dinosaurs loom large in our imaginations not just because they were in fact enormous, but also they are so ridiculously old. There has always been a big, impenetrable curtain separating us from prehistoric life. Sure, we have some ancient bones, but those had long since turned to stone. Any actual tissue, the stuff of flesh-and-blood creatures, is irrevocably lost, lasting only a few tens of thousands of years in most cases. Maybe a few stray organic molecules could persist for a few million if, say, they were frozen deep within primeval ice.</p><p>So, needless to say, it came as something of a shock when Mary Schweitzer <a href="http://www.sciencemag.org/content/307/5717/1952.abstract">discovered that she had some 68-million-year-old dinosaur tissue </a>on her hands.</p><p><img alt="Researchers at Argonne lab use tricycles to get around the Advanced Photon Sourc" class="caption" src="http://llnw.wbez.org/blog/insert-image/2012-March/2012-03-05/Orgel trike.jpg" style="margin: 10px; width: 350px; float: right; height: 267px;" title="Researchers at Argonne lab use tricycles to get around the Advanced Photon Source. (WBEZ/Michael De Bonis)">The find was and is controversial. <a href="http://genome.fieldofscience.com/2009/06/dinosaur-proteins-from-t-rex-and.html">Many scientists are skeptical or outright dismissive </a>of the idea that tissue could have persisted inside the partially fossilized thigh bone of a T. rex. But since then Schweitzer and her collaborators have gradually built up evidence that the find is real. And most recently, <a href="http://www.iit.edu/csl/bio/faculty/orgel_joseph.shtml">Joseph Orgel of the Illinois Institute of Technology </a>has begun to understand how mummified dino-flesh could possibly have survived a thousand times longer than was thought possible.</p><p>Orgel used <a href="http://aps.anl.gov/">x-ray diffraction</a>, a kind of molecular imaging technique, to understand how the dinosaur tissue is structured in detail. The particular stuff they have in hand is collagen, a material found in our bones, tendons, blood vessels and skin. It is itself a hardy molecule, and Orgel found that the protein sequences preserved in their fossils came from the innermost, protected part of the collagen fiber. So it’s possible that <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0020381">collagen’s tough, ropelike structure preserved a tender bit of dinosaur jerky inside.</a></p><p>Keep in mind, this is not DNA. We will not be cloning Barney from this stuff. But understanding how these proteins can be shielded from decay for so long could hold practical lessons for modern medicine. If you’re repairing, say, a bone or cartilage, you might be able to leverage or mimic nature’s ability to make durable organic materials that don’t degrade, in effect, forever.<img alt="Phillip Messersmith designed a medical glue based on the blue mussel's natural a" class="caption" src="http://llnw.wbez.org/blog/insert-image/2012-March/2012-03-05/Messersmith.jpg" style="margin: 10px; width: 250px; float: left; height: 333px;" title="Phillip Messersmith designed a medical glue based on the blue mussel's natural adhesive. (WBEZ/Michael De Bonis)"></p><p>Also in today’s episode, we consider another example of design inspired by biology. <a href="http://biomaterials.bme.northwestern.edu/mussel.asp">Dr. Phillip Messersmith’s muse is the blue mussel </a>– a bivalve that secretes a unique adhesive to stick itself to rocks or boat hulls or wherever it feels like sticking. (They form their connective threads and tacky pads through a kind of shellfish injection-molding process. The video below, provided by the Messersmith lab, captures an amazing example.) This stuff turns out to have some key qualities that a surgeon would envy. It starts as a liquid and solidifies quickly, it functions well under water and it’s sticky as hell.</p><p>That’s a big advantage over the medical glues out there that doctors use to attach or repair tissues. The safest ones are too weak. The strongest ones (basically, super glue) are toxic. <a href="http://biomaterials.bme.northwestern.edu/">Messersmith and his lab-mates at Northwestern University </a>are using the fundamentals of the mussel glue to design their own version, which they demonstrated for us on some sausage casing.</p><p>So someday, maybe they’ll be able to install a dino-inspired bone patch in your body, and lock it down with some mussel glue. Until then, don’t forget to subscribe to our <a href="http://itunes.apple.com/us/podcast/wbezs-clever-apes/id379051174" target="_blank" title="http://feeds.feedburner.com/CleverApesPodcast">podcast</a>, follow us on&nbsp;<a href="http://twitter.com/#%21/cleverapes" target="_blank" title="http://twitter.com/#!/cleverapes">Twitter</a>, and find us on&nbsp;<a href="http://www.facebook.com/pages/Clever-Apes-on-WBEZ/118246851551412" target="_blank" title="http://www.facebook.com/pages/Clever-Apes-on-WBEZ/118246851551412">Facebook</a>.</p><p><iframe allowfullscreen="" frameborder="0" height="451" mozallowfullscreen="" src="http://player.vimeo.com/video/38034455?color=ff0179" webkitallowfullscreen="" width="601"></iframe></p></p> Wed, 07 Mar 2012 16:30:00 -0600 http://www.wbez.org/blog/clever-apes/2012-03-08/clever-apes-27-breaking-fossil-record-96971