Colossal Biosciences is growing chickens in a 3D-printed artificial eggshell
Colossal Biosciences is growing chickens in a 3D-printed artificial eggshell
Colossal Biosciences 正在用 3D 打印的人造蛋壳孵化小鸡
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The baby chicks were shifting and starting to pip—or trying to hatch. But not from an egg. Instead, these chickens were growing inside transparent 3D-printed plastic cups at the Dallas headquarters of Colossal Biosciences. 小鸡们正在蠕动并开始啄壳——也就是试图孵化。但它们并非来自蛋壳。相反，这些小鸡是在 Colossal Biosciences 位于达拉斯总部的透明 3D 打印塑料杯中生长出来的。
The biotech company today claimed it has developed a “fully artificial egg” as part of its effort to resurrect extinct avian species, including birds like the dodo and the giant moa. But “artificial eggshell” would probably be a better description for the invention. It’s an oval-shaped printed lattice, coated inside with a special silicone-based membrane that lets in oxygen, just as a real eggshell does. 这家生物技术公司今日声称，作为其复活渡渡鸟和巨型恐鸟等已灭绝鸟类计划的一部分，他们已经开发出一种“完全人造的蛋”。但用“人造蛋壳”来形容这项发明可能更为贴切。它是一个椭圆形的打印网格，内部涂有一层特殊的硅基薄膜，像真正的蛋壳一样允许氧气进入。
To generate birds, Colossal took recently laid chicken eggs and carefully poured their contents into the artificial shells, where they continued growing. A window on top lets researchers peek inside. “To see them all moving around in their artificial eggs was absolutely mind blowing,” says Andrew Pask, the company’s chief biology officer. “You really feel you can grow life outside of the womb.” 为了培育鸟类，Colossal 取出刚产下的鸡蛋，小心翼翼地将其内容物倒入人造蛋壳中，让它们继续生长。顶部的窗口可以让研究人员窥视内部。“看到它们在人造蛋里四处活动，真是令人震撼，”该公司首席生物官 Andrew Pask 说，“你真的会感觉到，你可以在子宫之外孕育生命。”
Colossal was founded in 2021 with plans to use gene editing and reproductive technology to restore extinct species, including the woolly mammoth. It’s since raised more than $800 million toward what it now terms the “scalable and controllable” creation of animals. Colossal 成立于 2021 年，计划利用基因编辑和生殖技术来恢复包括猛犸象在内的已灭绝物种。自那时起，该公司已筹集超过 8 亿美元，用于其目前所称的“可扩展且可控”的动物创造项目。
According to Pask, the egg technology could help conserve at-risk bird species. It could also play a role in a project to re-create the extinct giant moa, a flightless 12-foot-tall bird that once lived in New Zealand and laid four-liter eggs, larger than those of any living bird. But Colossal may be able build one that’s big enough. The company provided a photograph of a prototype 3D-printed egg so large that staff have started to call it the “salad spinner.” 据 Pask 称，这项蛋类技术有助于保护濒危鸟类。它还可能在复活已灭绝的巨型恐鸟项目中发挥作用。恐鸟是一种曾生活在新西兰、身高 12 英尺且不会飞行的鸟类，它们产下的蛋容量达 4 升，比任何现存鸟类的蛋都要大。但 Colossal 或许能制造出足够大的蛋壳。该公司提供了一张 3D 打印原型蛋的照片，它大到员工们开始将其称为“沙拉甩干机”。
The moa went extinct after canoes carrying the ancestors of the Maori arrived on New Zealand’s South Island about 750 years ago. Archeological sites showcase the birds’ bones alongside stone cutting tools—clear evidence that they were hunted. 大约 750 年前，载着毛利人祖先的独木舟抵达新西兰南岛后，恐鸟便灭绝了。考古遗址中展示的鸟骨旁常伴有石制切割工具——这清楚地证明了它们曾遭到捕杀。
To be clear—Colossal isn’t close to re-creating the moa. Before that could happen, scientists would need to study DNA data from old moa bones and insert thousands of genetic changes into the genome of an existing bird, something that’s still technically difficult to do—with or without an artificial egg. 需要明确的是，Colossal 距离复活恐鸟还很遥远。在此之前，科学家需要研究恐鸟古骨中的 DNA 数据，并将数千处基因改变植入现有鸟类的基因组中，无论是否有这种人造蛋，这在技术上仍然非常困难。
Some scientists also think Colossal is taking too much credit for its artificial eggshell, which it announced in a thundering YouTube video intoning that the company has solved the “impossible question of which came first, the chicken or the egg.” The video is pure Hollywood—it’s meant to be funny and exciting. But Colossal has a habit of antagonizing scientists by making false and exaggerated claims. Last year, for instance, the company said it had re-created the extinct dire wolf—a claim widely rejected by experts. 一些科学家还认为，Colossal 对其人造蛋壳的功劳夸大其词。该公司在一段气势磅礴的 YouTube 视频中宣称，他们已经解决了“先有鸡还是先有蛋”这一“不可能的问题”。这段视频纯属好莱坞风格——旨在制造趣味和轰动效应。但 Colossal 有一种通过发布虚假和夸大声明来激怒科学家的习惯。例如，去年该公司声称已经复活了已灭绝的恐狼——这一说法遭到了专家的广泛驳斥。
This time, Colossal’s fluffed-up assertion of having created the “first-ever shell-less incubation system” is what’s raising hackles among the small flock of scientists who’ve been working on the technology for years. “Clearly an overstatement,” says Katsuya Obara, at the University of Tsukuba in Japan, who in 2024 hatched chickens from beneath transparent plastic film. “The technology here is essentially a modification of existing methods.” 这一次，Colossal 吹嘘自己创造了“史上首个无壳孵化系统”，这引起了多年来一直致力于该技术的一小群科学家的不满。“这显然是夸大其词，”日本筑波大学的 Katsuya Obara 说道，他在 2024 年曾成功在透明塑料薄膜下孵化出小鸡，“这里的技术本质上是对现有方法的改进。”
In fact, Obara notes, growing birds in artificial containers goes all the way back to 1998, when another Japanese group managed to do it with quail. What may be an advance by Colossal is the special membrane, which lets the embryo access more oxygen. Previous systems required scientists to supplement the gas—something that may not have been good for the chicks, as often some of them would fail to hatch. 事实上，Obara 指出，在人造容器中培育鸟类的历史可以追溯到 1998 年，当时另一个日本研究小组成功地用鹌鹑实现了这一目标。Colossal 的进步之处可能在于那层特殊的薄膜，它能让胚胎获得更多的氧气。以前的系统需要科学家人工补充气体——这可能对小鸡不利，因为它们往往无法孵化。
The work on the artificial eggshell was carried out in Dallas by Colossal’s exogenous development team, or Exo Dev. That group is also trying to develop artificial wombs for mammals, starting with marsupials. “We’re looking at every single facet of what’s happening during a mammalian pregnancy to unpack exactly how we then go about recapitulating that,” says Pask. 这项关于人造蛋壳的工作是由 Colossal 的外源性发育团队（Exo Dev）在达拉斯完成的。该团队还试图为哺乳动物开发人造子宫，并从有袋动物开始。“我们正在研究哺乳动物怀孕期间发生的每一个细节，以确切地解析我们该如何重现这一过程，”Pask 说。
For that team, an artificial eggshell is a relatively quick and easy technical win. That’s because chickens are already an example of ex utero development. After an egg is laid, a small embryo sitting on top of the yolk starts growing, drawing nutrients from the yolk, the white, and even the shell, which provides calcium. (Colossal says it has to add ground-up calcium to the artificial eggs.) 对于该团队来说，人造蛋壳是一个相对快速且容易实现的技术突破。这是因为鸡本身就是体外发育的例子。蛋产下后，位于蛋黄上的小胚胎开始生长，从蛋黄、蛋白甚至提供钙质的蛋壳中汲取营养。（Colossal 表示，他们必须在人造蛋中添加磨碎的钙。）
In order to create a moa, Colossal will have to genetically alter another type of bird, changing potentially thousands of DNA letters. But so far, chickens are the only bird species that can be genetically engineered. And that’s via a tricky process of editing stem cells that produce egg and sperm. Scientists have to add or delete DNA letters from these cells and then inject them back into an egg. The resulting bird will carry the genetic changes in its gonads—and then be able to pass them on. 为了创造恐鸟，Colossal 必须对另一种鸟类进行基因改造，可能需要改变数千个 DNA 字母。但到目前为止，鸡是唯一可以进行基因工程改造的鸟类。这需要通过编辑产生卵子和精子的干细胞这一复杂过程来实现。科学家必须从这些细胞中添加或删除 DNA 字母，然后将它们注射回蛋中。由此产生的鸟类将在其性腺中携带这些基因改变，并能够将其遗传下去。
Pask says Colossal’s idea is that it could modify avian stem cells enough to produce moa-like sperm or eggs. But then you might have the odd situation of a chicken laying an egg with a moa embryo inside it. “You would have chickens making moa egg and moa sperm. But it’s still a chicken egg,” he says. Pask 表示，Colossal 的想法是，他们可以充分改造禽类干细胞，从而产生类似恐鸟的精子或卵子。但这样可能会出现一种奇怪的情况：一只鸡产下了一个内部含有恐鸟胚胎的蛋。“你会让鸡制造出恐鸟的卵子和精子。但这仍然是一个鸡蛋，”他说。
Helen Sang, a professor emeritus at the Roslin Institute in the United Kingdom, says she’s not sure a moa embryo could survive on the yolk of a chicken egg, given evolutionary differences. “There are significant challenges to overcome to grow an embryo of a different species in artificial eggs,” says Sang. Just one of those is the huge size discrepancy. The amount of yolk in a chicken egg would hardly be enough to support the much larger moa chick. Yet Pask says that is exactly where the artificial egg will come in handy. He says it may be possible to use a fine needle to slowly “put 50 yolks together to make that yolk mass much larger.” “The chicken egg isn’t going to be big enough to…” 英国罗斯林研究所的名誉教授 Helen Sang 表示，考虑到进化差异，她不确定恐鸟胚胎能否依靠鸡蛋的蛋黄存活。“在人造蛋中培育不同物种的胚胎需要克服巨大的挑战，”Sang 说。其中之一就是巨大的体型差异。鸡蛋中的蛋黄量几乎不足以支撑体型大得多的恐鸟幼雏。然而，Pask 表示，这正是人造蛋派上用场的地方。他说，或许可以用细针慢慢地“将 50 个蛋黄合并在一起，使蛋黄团变得更大”。“鸡蛋本身不足以……”