Things that are awesome

The other day in class while I was struggling to keep my eyes open during another lecture on developemental disorders in Pathology, something caught my attention. Mind you, I generally do pay attention in Path, it's one of the most interesting classes we've got this block, plus I think developemental disorders are fascinating, but this is the second time around we've heard about most of these, so it gets a bit old.
Anyway.
So apparently clyclopia, eg. being born with only one eye, can be caused by a mutation in the sonic hedgehog gene...
I'll say it again, the SONIC HEDGEHOG GENE.

so


(As an aside, oh my dear goodness don't ever google image search "cyclopia" unless you want to be treated with images that will fuel your nightmares for years to come...)

Anyway, so this piqued my curiosity so I did a little research to find out what was going on here. It turns out that the Sonic Hedgehog gene is one of a set of other hedgehog genes, the other two being the less exciting Desert Hedgehog and Indian Hedgehog. Apparently the homologous structure in the zebrafish was at one time called the Tiggywinkle Hedgehog gene though, which is also fantastic.
The Hedgehog proteins are so named because in the fruit fly, if you create a mutant with nonfunctioning copies of this gene, the resulting embryo has little spiny projections all over it. Sonic the gene just happened to be discovered right around the same time that the original blue hedgehog debuted to the gaming world and, well, scientists are nerds.
The little Sonic Hedgehog is actually seriously seriously important to proper growth and development of embryos, for everything from spinal cord formation to parts of the brain to limbs. While fruit flies apparently get cool spikes if they knock out this gene, most vertebrates will just get terrible deformities. Sonic is part of the morphologic set of genes that guides the proper patterning of body systems.
So everybody with two functioning eyes and the normal complement of limbs, you can thank Sonic Hedgehog, toiling away in your embryonic cells for you.



Incidently, apparently there is an inhibitor to the Sonic pathway that has been dubbed Robotnikinin.
And that's just awesome.

Odd tics of mine

I apologize to dead things. This occured to me today as I was walking across the parking lot to school and found a dead baby bird lying on the concrete. It was pale and almost completely featherless, just a tiny gray tuft of down on its back. I have no idea where it came from, it was lying in the middle of the parking lot, there wasn't anywhere nearby where it could have fallen from and it certainly hadn't been old enough to move itself. I crouched there for a minute studying it's tiny little body, then I got a stick and moved it the grass on the edge of the lot. And I apologized. I don't know why I apologize to dead things. I'm not particularly convinced of any sort of afterlife or the persistence of conciousness after death, though I'd like to. I guess it's my way of acknowledging the life it didn't get to lead.

Also, I hug books. Only good books mind you. When I finish a book I enjoyed I hug the book before I put it away. I'ts my closure, because I'm bad at ending things.

Things that can kill you, pt. 1

Lets talk about babies, shall we?

Specifically a couple of fascinating (to me anyway, and since I'm the only one currently reading this blog I may as well amuse myself) tidbits found in my immunology notes regarding immune response to babies.

Now your immune system is kind of a scary thing to begin with. Imagine if you will a small army of well trained, endlessly paranoid, constantly vigilant militia groups hanging around in your body just waiting for somebody to look at them funny. This is essentially what your immune system is, and they're not exactly the brightest bunch either. It's difficult not to anthropomorphize one's immune system when the vast majority of immunology lectures would work almost perfectly as a zombie metaphor. But that's a post for another day.

Now when you (or somebody else) gets pregnant, the body has to do something to keep that paranoid little militia from going into attack mode against what is essentially a parasite hanging out in your womb for however many months. So your immune system gets put into lockdown for a while. Fun fact, around 70% of mothers with rheumatoid arthritis (which is an autoimmune disease attacking their joints) have lessened symptoms while they're pregnant. So if you're suffering from certain autoimmune diseases, get pregnant a lot I guess.



Well that's the first interesting thing, now for one of those things that makes you amazed you managed to survive. Neonatal Isoerythrolysis, which is a nicely clinical way of saying that your immune system is killing your baby after they've already been born. The way it works is that when a baby is newborn, they have essentially no functional immune system. It usually takes a little while to catch up with the whole birth thing. While the little militia is pulling its boots on, the mother provides the baby's first immune protection in the form of antibody-laden milk called colostrum. Colostrum is only secreted for the first day or so and provides a sort of basic protection for the baby while it's own system is coming on line. Cool huh? Well here's where it gets scary. In that disease that I mentioned at the top of the paragraph and don't feel like typing out again, the mother's immune system somehow gets ahold of baby red blood cells (usually following multiple childbirths) and goes into full on attack mode. Now while the baby's in utero this won't matter because that immune system can't get to it. However, once the thing's borne, that passive immunity in the colostrum gets into the baby, thinks "OH GOD WE'RE UNDER ATTACK!" and immediately sets to destroying red blood cells.
Isn't that just horrifying? It's usually not fatal since the colostrum immunity doesn't last too long, but the idea of getting finally out into the world and then having your mother's milk killing your blood
is enough to make anybody a little queasy.
Seriously, it's amazing anybody manages to survive to adulthood.

aww