Student Report: Zebra Fish Retinas + Dye = Angst

This week I’ve been diving in a little more into doing some actual research myself. Nothing breakthrough mind you, just some simple experiment to sort of understand the world around and inside of me a little better. My partner and I are looking into how the optic nerve develops inside of zebra fish and how its development may be affected by developing the fish in total darkness. We are trying to stain 1-2 day old zebra fish with Dye-I by simply poking the dye into the retina with any sort of small sharp object we can find. We’ll then separate the groups of stained fish into those that develop in a small flask with normal exposure to light (about 10-15 hours a day of UV light) and those that develop in a tin-foil-wrapped flask with no UV exposure in which feeding will be done under red light.

Every few days, I hope to take some of the fish out and look at how their brains are developing using a fluorescent microscope that allows me to see how the dye is traveling. With any luck, I’ll see a decently clear pattern of paths of nerves from the retina to the lateral geniculate. I’m not sure where it leads from there as the zebra fish has mainly the midbrain rather than our large forebrain with a thalamus and cerebral cortex. More research on my fish is definitely needed before I can do any real analyzing of the staining technique, but my real problem right now is just getting some fish stained!

Using a pin head dipped in dye, I had been trying to poke the retinas of these fish. Once the retina ruptures, almost any amount of dye should stain the retina and lead to further staining of the optic nerve as development continues (from what I’ve read, usually the rods and cones develop about 4 days at the earliest). I ran into many problems with this of course and have been fishing (oh so hilarious, I know) for new solutions ever since.

The first problem I had is that the head of the pin is about the size of the fish’s eye itself, so trying to rupture the eye with it is like trying to shove a baseball bat through my own. Of course actually rupturing the retina with this gigantic tool will only happen if my mounted fish would stop moving every time I get close to it, which is the second problem. So far, I’ve created new tools by heating TLC spotters over a flame in the organic chemistry lab and then pulling it in half so that the glass is pulled into a tiny pipette with a head just smaller than the fish’s retina. This has been successful after coupling it with a technique for knocking out my fish to keep them still. I burst a small bubble of anesthetic (0.5 MESAB) over the water that I’m using to mount my fish before injecting the fish in augar onto the slide. This does a great job in keeping the fish still so I can do my dirty work of staining its eye, but sometimes the concentration of anesthetic is too strong and the fish will die. All in all, with much more research and some patience this may turn out to be a fun little project. If you have any ideas as to where I should be looking for research and anything else I could be doing with this experiment, let me know.
~Bright Lights

Thank god for Salma Hayek’s breasts

Salma, Salma, Salma…you heard about my thread to name the feeblest reason for believing in Christianity, and you couldn’t just leave a comment like everyone else? You had to go running to the press to submit your entry?

Mexican actress SALMA HAYEK was so upset by childhood jibes about her flat-chest, she would pray to God for larger breasts. The Ugly Betty star reveals she was bullied for having small breasts as a youngster – and decided to turn to her Catholic religion for help. She says, “My mom and I stopped at a church during a road trip we were making from our home in Mexico. “When we went inside, I prayed for the miracle I wanted to happen. I put my hands in holy water and said: ‘Please God, give me some breasts’. “And he gave me them! Within a few months, I developed a growing spurt, as teenagers do, and I was very pleased with the way I grew outwards.”

They are very nice, Salma, but you should really give credit where credit is due: genes, steroid hormone receptors, steroid hormones, diet, and a million years of chance and selection.

Have a ticky-tacky Christmas!

It’s awfully hard to get into the spirit of the War on Christmas when Christians are so danged tacky. I mean, really…the Jesus loves you sucker is only one comma away from perfect honesty, while the Jesus Tree Topper with the silk gown, gold crown, nail prints in the hands, and built-in light is pure cheese. He really needs a complement, though: Naked Tormented Jesus with Stigmata Squirting Action. Then the kids could battle it out between ascetism and the prosperity gospel right there on the Christmas tree.

Jebus, no … what a miserable idea

Clive Thompson wants us to simply redefine the “theory of evolution” as the “law of evolution”. This is possibly one of the worst ideas I’ve heard yet for overcoming the problem of the colloquial definition of theory. It is not correct. The theory of evolution is a whole collection of ideas describing complex phenomena; it is not reducible to the kind of clear and simple mathematical description we associate with scientific laws. When somebody asks me what the ideal gas law is, I can say PV=nRT; when someone asks me what the law describing the gravitational attraction between two bodies is, I say Gm1m2/R2; when they say, “OK, smartie pants, what is the law of evolution?”, what am I supposed to do? Recite Hardy-Weinberg at them (which, by the way, is called a law already, but is not the sum of all of evolution by any means)?

It’s a bad idea that sets us up for more confusion and will play right into creationist hands. Why not go all the way and just call it the “Truth of Evolution”? It’s the same strategy — it’s all avoiding the issue by an attempt at redefinition, and mangling the idea in the process.

(Larry Moran sees it the same way I do. He must be a very smart man.)

(And Wilkins was way, way ahead of us both.)

Nigersaurus, a Cretaceous hedge-trimmer

Blogging on Peer-Reviewed Research

Last August, when I was at the Sci Foo camp, Paul Sereno brought along the skull of one of his latest discoveries…and whoa, is it ever a weird one. This is Nigersaurus taqueti, an herbivorous dinosaur with specializations for ground-level grazing. Look at this picture; in reality, it’s even more striking.

i-f4ef9d4d5fa37f0f9e2b1f2b0c6e53f2-nigersaurus.jpg

Those jaws and teeth—they are so neatly squared off and flat-edged. In addition, the skull itself on the spinal column is turned habitually downward. This is a creature that kept its face pressed to the ground as it nibbled its way across the landscape.

Another feature that was apparent is that the skull is awesomely light — it’s mostly empty spaces with a delicate webwork of bony struts holding it together. It’s so specialized it’s almost comical, and you can imagine something like this appearing on the Flintstones as a lawn mower or hedge trimmer.

Bora has more, and you can read the original on PLoS.

Sereno PC, Wilson JA, Witmer LM, Whitlock JA, Maga A, et al. (2007) Structural Extremes in a Cretaceous Dinosaur. PLoS ONE 2(11): e1230. doi:10.1371/journal.pone.0001230

HuffPo follies

I’m not a fan of the Huffington Post — I see too much support for clowns like Chopra and anti-scientific thinking like Robert Kennedy’s — so I guess I shouldn’t be surprised at this. Matthew Chapman posted his suggestion for a presidential debate on science there. This is the same issue I thought was a good idea, but cynically suspected none of the candidates would ever go for it. The response on HuffPo was to a large part deranged.

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