章鱼的智慧可能与某种前所未见的突变有关。
Octopus intelligence may be related to never-before-seen mutation

原始链接: https://www.smithsonianmag.com/smart-news/why-are-some-octopuses-so-smart-the-answer-might-lie-in-a-never-before-seen-mutation-that-helps-them-accurately-build-proteins-180989319/

研究人员在某些章鱼体内发现了一种独特的基因突变,这或许能解释它们非凡的智力和复杂的神经系统。《当代生物学》杂志发表的一项研究发现,这些章鱼拥有一种特殊的核糖体RNA(rRNA)“断点”,使它们能够以两倍于寻常的准确度合成蛋白质。 这种适应性存在于以复杂行为著称的浅海章鱼中,但在其深海近亲和鱿鱼身上却不存在。科学家认为,蛋白质合成精度的提高可能保护了长寿命神经元免受蛋白质错误折叠的危害,从而可能推动了章鱼复杂大脑的快速演化。 尽管尚需进一步研究以证实其直接因果关系,但这一发现对细胞生物学具有重要意义。由于这些章鱼拥有一种确保蛋白质高保真合成的机制,研究人员希望利用这些发现,通过在人体细胞中模拟这种天然的“质量控制”过程,为阿尔茨海默病和帕金森病等人类神经退行性疾病开发新型疗法。

```Hacker News最新 | 往期 | 评论 | 提问 | 展示 | 招聘 | 提交登录章鱼的智力可能与前所未见的突变有关 (smithsonianmag.com)7 分,由 bookofjoe 发布于 1 小时前 | 隐藏 | 往期 | 收藏 | 2 条评论 帮助 throw310822 12 分钟前 | 下一条 [–] 像往常一样,史密森尼杂志纯粹是无耻的标题党。> 虽然没有直接证据表明这种适应与章鱼智力的提升有关,也就是说,这种突变与章鱼智力之间的全部联系都是编造的。甚至连一点依据都没有。回复jjk166 8 分钟前 | 上一条 [–] 相关性并不意味着因果关系,而且甚至不清楚这是否能算作相关性。回复 指南 | 常见问题 | 列表 | API | 安全 | 法律 | 申请 YC | 联系 搜索:```
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原文
Yellow-tan octopus with darker colored webbing
Researchers made the discovery while studying the California two-spot octopus. Anik Grearson / Bellono Lab

Octopuses are incredibly clever creatures. They can open jars, solve mazes and even use tools. One species, the common blanket octopus, wields venomous tentacles ripped from the Portuguese man o’ war as weapons.

Now, researchers have discovered a mysterious mutation in some octopuses that might explain their intelligence. A study published in the August 17 issue of the journal Current Biology reveals that the eight-limbed creatures can produce proteins with extreme accuracy thanks to a variation never seen in any other animal. Although there is no direct evidence that the adaptation is linked to expanded octopus brainpower, only a lineage of creatures with enlarged nervous systems and that can carry out complex behaviors appears to have the mutation.

Scientists made this discovery by accident. About five years ago, study co-author Richard Han, then a graduate student at Harvard Medical School, was examining molecules called ribosomal RNA (rRNA) in tissues from the California two-spot octopus. The molecules create a 3D scaffold for ribosomes, the cells’ protein factories.

Many sequences of rRNA remain pretty much the same across all known animals. But Han noticed something unusual in those from the octopus: an unexpected gap that broke what’s usually one rRNA fragment in other creatures into two.

“We figured we were bad at extracting RNA” and simply had made a mistake, says study co-author Nicholas Bellono, a molecular biologist at Harvard, to Sara Reardon at Science.

Further tests, however, confirmed that something else was going on. Inserting the same break in the ribosomes of Escherichia coli bacteria made the engineered cells produce proteins with about twice their usual accuracy.

To examine when the strange rRNA feature evolved, the team compared two groups of octopuses that diverged more than 100 million years ago: incirrates, shallow-water octopuses with developed nervous systems that support complex behaviors, and cirrates, deep-sea creatures with simpler nervous systems adapted for slow swimming and passive feeding.

The rRNA break was present in all five examined incirrate species, the team found. But a sample from a cirrate—specifically, a dumbo octopus—lacked the gap. Squids, which diverged from octopuses about 300 million years ago, also didn’t have it.

Fun fact: Self-editing

Cephalopods, an animal group that includes octopuses, squids, cuttlefish and nautiluses, are masters of editing their own RNA—molecules that carry instructions from DNA to help build proteins. They do it far more often than other creatures do. In a study published in 2023, researchers reported that octopuses heavily edit RNA in their brains to brave frigid water.

The findings hint that the rRNA adaptation might be connected to the evolution of the shallow-water octopuses’ large nervous systems. Their brains—which are spread throughout their bodies—had to expand quickly as they learned to keep up with predators and increased competition in this environment. Nerve cells, or neurons, are long-lived, study co-author Rishav Mitra tells Scientific American’s Cody Cottier, which means protein misfolding is particularly bad for them. By preventing that, the rRNA break “might help these neurons to work well,” he adds.

“The major surprise is that the ribosome, which is highly conserved across life, can actually undergo evolutionary changes that impact function, and may even contribute to new innovations” study co-author Amy Lee, a cell biologist at Harvard, says in a statement.

Joshua Rosenthal, a molecular biologist at the Marine Biological Laboratory who wasn’t involved in the work, calls the discovery “super interesting,” although he notes that more research is needed to prove whether the rRNA change drove the evolution of sophisticated brains and behaviors. “We’re just getting to the beginning of genetics with these organisms,” he tells Science.

The study authors suspect their findings may lead to potential therapies for neurodegenerative diseases like Alzheimer’s disease and Parkinson’s disease that involve misfolded proteins in the brain. Lee tells Scientific American that she hopes that it will be possible to design drugs that copy the octopus mutation for accurate protein synthesis.

If we “use nature as a guide to understand how that happens naturally,” she says, “then we can probably find ways to put it into human cells.”

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