Animeme

Chris Clarke callously infected me with a meme. I’m supposed to answer these five questions.

An interesting animal I had

An interesting animal I ate

An interesting animal in the Museum

An interesting thing I did with or to an animal

An interesting animal in its natural habitat

My first thought was, “Dude! These are awfully personal questions. Why are you asking for these intimate details of my sex life?” But then I noticed that he brought up my little friend Snowball (you may not want to read that), and all of his stories were about non-human animals. Oh. Never mind. That’s completely different.

Or maybe not so different…

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Basics: Master Control Genes and Pax-6

Blogging on Peer-Reviewed Research

One concept that is sometimes used in developmental biology is the idea of the “master control gene” or “master switch” — a single gene whose expression is both necessary and sufficient to trigger activation of many other genes in a coordinated fashion, leading to the development of a specific tissue or organ. It’s a handy concept on which to hang a discussion of transcription factors, but it may actually be of rather limited utility in the real world of molecular genetics: there don’t seem to be a lot of examples of master control genes out there! Pax-6 is the obvious one, a gene that initiates development of the eye, and other genes may be mentioned in certain stem cell pathways, but even in the eyes of vertebrates, for example, eye development is more complicated than a single switch, and similarly, many other developmental processes seem to use multiple or redundant regulatory controls — the cases where we have a single gene bottleneck are either rare or poorly represented in the literature.

They’re still at least pedagogically useful, though — it’s a simple case of imposition of a specific developmental pathway on a patch of tissue.

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Marine invertebrate temptations

People, don’t do this to me. I’ve got all this work I’ve got to get done so that I’m free to go on a date this evening, and you keep sending me these distractions. Like, for instance, this link to a collection of Marine Invertebrate Video and Film Stock Footage. Cephalopods and nudibranchs and crustaceans and salps, all categorized (there’s even an invertebrate mating category! With 421 clips! It’s free porn!) and with thousands of high resolution videos. The previews are all free, but you can also license HD video of these beautiful action shots.

I will be disciplined, though. I’m closing the web page. I will get my writing done. I will put these links here though, so I can later return to “Brain coral spawning” and “Moray tears arms from octopus” and “Flamboyant cuttlefish feeding” and “Siphonophore With Extending Tenacles”.

Back to work.

Maybe there’s time for “Pelagic Tunicate In The Twilight Zone”?

No. Work. Get things done.

Oh, but I want…!

Jaws of the moray

Blogging on Peer-Reviewed Research

The vertebrate jaw is a product of evolution — we have a serially repeated array of pharyngeal structures as embryos (and fish retain them in all their bony glory as gill arches), and the anterior most arch is modified during our development to form the jaws. The fact that they’re serially repeated raises an interesting possibility: what if, instead of just the one developing into a jaw, others were transformed as well? You could have a whole series of jaws!

One animal has done exactly that. The moray eel has modified one of the more posterior pharyngeal arches into a second pair of jaws, with a set of muscles that can slide it forward to bite prey already held in the mouth.

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