as small as a world and as large as alone

11:18am August 3, 2014

ajax-daughter-of-telamon:

swimmiesofdoom:

annalevys:

charminultrasoftbutch:

annalevys:

these scientists tried to do a test involving fish and autism but since they couldnt detect autism in fish, they just used gastrointestinal dysfunction and big heads and said that fish that have those characteristics are “autistic fish” and im laughing because scientists are ridiculous, stop them now

oh my god. oh. my. god.

thanks for putting the link! its even better than the article i read tbh

“In their study of 6,176 children with autism spectrum disorder, researchers found 15 had a CHD8 mutation and all these cases had similar characteristics in appearance and issues with sleep disturbance and gastrointestinal problems. Bernier and his team interviewed all 15 cases with CHD8 mutations.

To confirm the findings, researchers worked with scientists at Duke University who do zebra fish modeling. The researchers disrupted the CHD8 gene in the fish and the fish developed large heads and wide set eyes. They then fed the fish fluorescent pellets and found that the fish had problems discarding food waste and were constipated. Bernier said this is the first time researchers have shown a definitive cause of autism to a genetic mutation.”

a finding that only was true for 15 children out of 6176 children and some fish with big heads and they’re declaring it a huge discovery

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we read and reread this.  and then read it again.  it looks like out of 6,176 autistic human children they found 15 with a disrupted CHD8 gene that caused “appearance” similarities, sleep problems, and GI issues.  they took zebra fish (why zebra fish?  what is it about zebra fish, specifically, that made them say Oh, hey, let’s model this in zebra fish!), disrupted the CHD8 gene, caused their appearance to change similarly to each other, and found they had GI issues.

AND FROM THIS DEDUCED AUTISM IS CAUSED BY A GENETIC MUTATION???

not, maybe, that GI issues and weird looks are caused by a genetic mutation?  and how did they know the fish developed autism too?  did the fish refuse to make eye contact?  did the fish start thinking differently from other zebra fish?  how do zebra fish “normally” think?  how do they know zebra fish aren’t autistic to begin with as a default?

what the hell is an autistic fish?  or an allistic fish, for that matter?

we are confused.  but not as confused as this bernier human person who somehow got a degree without ever learning what the term “non sequitor” means.

This is actually the sort of thing I was trained in, so I can explain some of it to you!

OK, zebrafish! Zebrafish are one of several “model organisms” commonly used by scientists studying genetics or developmental biology because their genome has been completely mapped, is very well understood (because mapping a genome and actually knowing what all the genes and regulatory elements do are different things, and the former is necessary but not sufficient to ensure the latter), has a fairly short generation time, and a large embryo that makes it easy to see what’s happening throughout development.

They are closer to humans on the evolutionary tree than some other common model organisms like fruit flies and nematodes, if not as close as, say, mice or rats or monkeys.

So that’s why zebrafish. 

But as far as your other questions — what is an autistic fish, how do zebrafish normally think, why is a mutation that only about one-fourth of one percent of all the autistic people they studied even have being seriously considered as a cause of autism — I can’t answer because there is no good answer. There’s no such thing as an autistic fish, and I’ve been meaning for a while to write a post on my other blog about exactly what each “animal model” of autism that’s ever appeared in research actually has going on in terms of its neurology, because that’s usually the closest they can get — knocking out genes relating to neurodevelopment gives you animals with neurological abnormalities, and it seems to me like whatever those abnormalities might be, they get interpreted as “autism” by researchers if the knocked-out gene was first discovered in autistic humans. Even if those autistic humans also had other neurodevelopmental disabilities or genetic conditions, as they frequently do. (And as the children in this study almost certainly do).

Also, if you thought 15 out of 6,176 was bad, well, that’s about the usual level of prevalence for every mutation that turns up in the ongoing hunt for Genetic Causes of Autism. 

I am highly unfond of animal models of autism.

But I would not be surprised if there turned out to be literally hundreds of different genes and gene combinations that caused autism, resulting in each one being a tiny percentage of any given sample.

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