A neurological mechanism for Fragile-X disease

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I’m busy preparing my lecture for genetics this morning, in which I’m going to be talking about some chromosomal disorders … and I noticed that this summary of Fragile-X syndrome that was on the old site hadn’t made it over here yet. A lot of the science stuff here actually gets used in my lectures, so they represent a kind of scattered online notes, so I figured I’d better put this one where I can find it.

I haven’t even finished grading the last of the developmental biology papers, and already my brain is swiveling towards the genetics literature, as I get in the right frame of mind to teach our core genetics course in the spring. And, lo, here is a new paper in PNAS that addresses details of a topic I bring up every time.

There are a surprising number of heritable diseases that share a couple of common traits: they are neurodegenerative, causing progressive loss of neural control, and they also exhibit a phenomenon called genetic anticipation—they tend to get worse, with earlier onset and more severe affects with each generation. Some of these diseases may be rather obscure, for instance
Haw-River Syndrome (AKA Dentatorubral-pallidoluysian atrophy),
Friedreich Ataxia,
Machado-Joseph Disease, or
X-linked Spinal and Bulbar Atrophy Disease (AKA Kennedy Disease), but others you’ve probably heard of, like
Myotonic dystrophy and
Huntington Disease. These are dreadful diseases that are variable in their pattern of appearance, and have terrible symptoms, like loss of motor control, chorea, seizures, dementia, and eventually, death.

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Optical Allusions

Jay Hosler has a new book out, Optical Allusions(amzn/b&n/abe/pwll). If you’re familiar with his other books, Clan Apis(amzn/b&n/abe/pwll) and The Sandwalk Adventures(amzn/b&n/abe/pwll), you know what to expect: a comic book that takes its science seriously. Hosler has a fabulous knack for building serious content into a light and humorous medium, just the kind of approach we need to get wider distribution of science into the culture.

This one has a strange premise. Wrinkles the Wonder Brain is an animated, naked brain working for the Graeae Sisters, and he loses the one eye they share between them — so he has to go on a quest to recover it. I know, it sounds like a stretch, but it works in a weird sort of way, and once you start rolling with it, you’ll find it works. Using that scenario to frame a series of encounters, Wrinkles meets Charles Darwin and learns how evolution could produce something as complex as an eye; talks about the sub-optimal design of retinal circuitry with a cow superhero; discovers sexual dimorphism with a crew of stalk-eyed pirates; learns about development of the eye from cavefish and a cyclops; chats with Mr Sun about the physics of radiation; there are even zombie G proteins and were-opsins in a lesson about shape changing. This stuff is seriously weird, and kids ought to eat it up.

It isn’t all comic art, either. Each chapter is interleaved with a text section discussing the details — you can read the whole thing through, skipping the text (like I did…), and then go back and get more depth and directions for future reading in the science. This is a truly seditious strategy. Suck ’em in with the entertainment value, and then hand ’em enough substance that they might just start thinking like scientists.

It’s all good stuff, too. A colleague and I have been considering offering an interdisciplinary honors course in physics and biology with the theme of the eye, specifically for non-science majors, and this book has me thinking it might make for a good text. It’ll grab the English and art majors, and provide a gateway for some serious discussions that will satisfy us science geeks. I recommend it for you, too — if you have kids, you should grab all of Hosler’s books. Even if you don’t have kids, you’ll learn a lot.

Jay Hosler also explains the intent of the project, and you can read an excerpt.

Franklin Institute Awards

Look: it’s possibly the world’s most annoying, boring video. Turn the sound down, it’s a car driving in traffic with a siren howling.

Of course, if you look a little bit more closely, you might notice…nobody is driving! This is an exercise in robotics and computer vision, and it’s one of the achievements that is winning the Franklin Institute Awards this week. Any lucky Philadelphians might want to make it a point to visit the Franklin Institute (which was one of our favorite museums when we lived in Philly) this week — they have a slate of events coming up associated with handing out these prestigious awards. It’s not just robotics, either: miRNAs are recognized, as well as the structure and origin of nucleic acids, and the ocean’s effect on climate change, ultra cold physics, and artificial intelligence.

There’s something for everybody, so it’s a good time to think about stopping by.

The Sunday morning session at the Oregon evo-devo symposium

[Since I had to fly away early this morning and missed all these talks, I had to rely on regular commenter DanioPhD to fill in the gaps … so here’s her summary:]

This morning’s final series of talks each focused on a different phylum, but the unifying theme was one of bridging the processes of microevolution and macroevolution. The first talk after breakfast (and a long night of Scotch-drinkin’ and story-swappin’ prior to that) was Bernie Degnan of the University of Queensland. He summarized his work on Amphimedon queenslandica, a sponge species developed as a model of a representative primitive metazoan. Sponges diverged from the metazoan lineage ca. 700 MYA and possess the most minimalist metazoan body plan–no nervous system, muscles, nor any discernible tissues in the adult body architecture. Their embryos, however, feature robust anterioposterior patterning, distinct cell types organized into tissues, and cell morphogenesis typical of more complex metazoans. These embryonic characteristics are achieved by a regulatory network of genes, which, while inactive in the adult sponge, strongly support the presence of similar molecules in the ancestral metazoan genome. A few million years after the divergence of porifera, metazoans were able to co-opt these molecular toolkits to build the diverse, molecularly and morphologically distinct tissues common to all bilaterians. PZ has previously written up one such sponge tale here describing the molecular precursors to a nervous system in the sponge genome. Precursors to pretty much every other developmental ‘big gun’, e.g, Hox genes, Pax genes, Wnts, Hedgehog, etc. are also present as a basic prototype, in the Amphimedon genome.

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The afternoon session at the Oregon evo-devo symposium

I’m going to get off a quick summary of this afternoon’s talks, then I have to run down to the poster session to find out what the grad students have been doing. Are we having fun yet? I’m going to collapse in bed tonight, and then unfortunately I have to catch an early flight back home, so I’m going to miss a lot of cool stuff tomorrow.

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The morning session at the Oregon evo-devo symposium

My brain is most wonderfully agitated, which is the good thing about going to these meetings. Scientists are perverse information junkies who love to get jarred by new ideas and strong arguments, and meetings like this are intense and challenging. I’ve only got a little time here before the next session, so let me rip through a short summary of my morning.

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Coyne and Wray at the Oregon symposium on evo-devo

So here I am at the IGERT Symposium on Evolution, Development, and Genomics, having a grand time, even if I did get called out in the very first talk. There were two keynote talks delivered this evening, both of which I was anticipating very much, and which represented the really good side of science: two differing points of view wrestling with each other for consensus and for testable, discriminating differences. They also had dueling t-shirts.

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Look up!

What an honor: Jeff Medkeff, an astronomer and discoverer of asteroids, has been generous to name a recently discovered set of distant rocks after Michael Stackpole, Rebecca Watson, Phil Plait, and me. That’s right, there is now a few billion tons of rock and metal spinning overhead with my name on it, asteroid 153298 Paulmyers. You can find a picture of its orbit and location, just in case you want to visit.

Now I don’t know much about astronomy — I know this rock doesn’t have any squid on it, unfortunately, and that it’s small, cold, and remote (hey, just like where I am now! Only more so!) — but Phil Plait describes the details of his asteroid.

To give you an idea of the asteroid’s size, it has more than 200 times the volume of Hoover Dam. Assuming that it’s made of rock, it has a mass of about 2 quadrillion grams, or about 2 billion tons. If it’s metal it’ll be about twice that massive.

When I mentioned this to Skatje, the first thing she asked was whether mine was bigger than Phil’s. Phil admits that it probably is twice the size, although it’s an estimate from relative brightness, so it could be that they’re of similar size, but mine is brighter, or Phil’s is dimmer … it’s all good. The rivalry continues!

Now I have to wonder…do I have mineral rights? Can I at least retire to 153298 Paulmyers? When’s the next space bus to the asteroid belt? How about some photos of my rock (near as I can tell, any photo is going to be just of a tiny point of reflected light)?