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Comment by ladberg | Hacker News Reader

For anyone coming to the comments before reading the article: the squid is already clear, they just removed some spots of pigment.

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And the advantage here is that it's the start of development of a genetic-modification toolkit (similar to that we already have for fruit flies and c elegans and zebrafish) for using them as animal models. Much more complex of a brain than any of the other animal models we usually use.

Isn't this a bit of a slippery slope? The better a model of a human brain you experiment on, the closer you approach the ethics of performing the same experiment on human embryos, infants, children, and adults (as they age). I think this is already pretty close to the case for mice, but when you start doing it to cephalopods, primates, and dolphins/orcas, you're really skirting the line.

I wonder if there'll ever be a time where if we aren't comfortable with doing something to human embryos (or other stages) in experiments, we also won't be comfortable doing it to the animals closest to us on the intelligence and awareness totem pole, and eventually perhaps any sentient animals at all (so nearly all of them besides jellyfish, sponges, anemomes, and some other ocean dwellers). This day feels inevitable to me, but I don't know whether it's 20 years or 200 years away.

We're still chopping up likely-sentient animals and eating them, so it's probably a ways off..

I believe I read this in the book Grandfather by Tom Brown [1] (could have been somewhere else). The author was taught by an Apache elder about survival, etc.

Part of that was learning how to track and hunt.

The first time he killed a deer, he was required to sneak up on the deer and kill it with a knife. That way he would know the gravity of what he was doing.

He wrote that he cried for a good while afterwards.

I think that is a perspective more people should take with eating meat. To know you are taking the life of a living, breathing thing to sustain your own life.

I think it used to be a much more common view, but it's hard to view a chicken nugget or a hamburger as an animal that lost its life to continue yours.

[1] https://www.goodreads.com/book/show/434013.Grandfather

There's also the problem that for most people in developed countries, you don't actually need to take a conscious life to sustain your life. It's a luxury, like wearing fur.

Indeed. But many experiments are more cruel to sentient beings than, say, getting shot by a hunter. I'd much prefer to be summarily executed than to end up in Mengele's lab. Both are wrong, but one is worse.

Wait until you read about pig intelligence levels. And unfortunately, it seems I still love ham and bacon :-(

The reason this is a significant achievement is that the DNA of living cells in the organism were "edited" to remove the pigmentation, thereby effectively changing the phenotype of an adult squid.

They edited embryos:

we determined whether a TDO-selective inhibitor (680C91) impeded pigmentation in developing embryos. The development of D. pealeii has been divided into 30 stages and eye pigmentation appears at ∼stage 25, while chromatophore pigmentation starts at stage 26 [21]. We added 680C91 to developing embryos at stage 20

While you're right they edited the embryos the sentence you quoted is describing a drug (680C91) that they bath-applied to inhibit the TDO enzyme (as a positive control), rather than the CRISPR strategy they used, in which they injected the Cas9 and sgRNA into the embryo.

Oops, I should have quoted this part, from the summary:

Knocking out TDO in squid embryos efficiently eliminated pigmentation. By precisely timing CRISPR-Cas9 delivery during early development, the degree of pigmentation could be finely controlled.

Still impressive, but definitely not as complicated as taking an opaque squid and making it clear.

Thank you! I don't like admitting to this behavior, but I can't trust a headline (any headline).

They missed a spot! Sorry, couldn't help myself.

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