让动物长出人类器官？日本人兽杂交胚胎实验获批

科幻片《人兽杂交》中半人半兽的生物很可能将会成为现实。近日，日本批准了创造含有人类细胞动物胚胎的实验，并且可以让这些胚胎移植到动物体内并被足月分娩。预计实验成果将用于人类器官移植。

 Japan's government approved a request by scientists to conduct stem-cell experiments to create an animal-human hybrid and allow it to be brought to term.

日本政府近日批准科学家开展培育人兽杂交胚胎的干细胞实验，并允许其足月分娩。

Japan's science ministry last week gave provisional approval to a proposal from researchers at the University of Tokyo to create animal embryos that contain human cells and transplant them into surrogate animals, Japan's Asahi Shimbun newspaper reported.

据日本《朝日新闻》报道，日本文部科学省上周为东京大学研究人员的一项研究议题发出临时许可，该研究计划培养含有人类细胞的动物胚胎，并将其移植到代孕动物体内。

surrogate ['sʌrəgət]：adj.替代的，代理的

The study would create a human pancreas in rodents using human induced pluripotent stem (iPS) cells. According to UCLA's Broad Stem Cell Research Center, these are cells that have been reprogrammed back into an embryo-like state and can be used to create virtually any other type of cell.

这项研究将利用人类诱导多能干细胞（iPS）在啮齿动物体内形成人类胰腺。据加州大学洛杉矶分校布罗德干细胞研究中心介绍，这些细胞已经被重新编程回到胚胎状态，可以用来创造几乎任何其他类型的细胞。

pancreas ['pæŋkrɪəs]：n.胰腺

rodents['rodnt]：n.啮齿动物，啮齿类

reprogram：[riː'prəʊgræm]：v.为……重编程序。细胞核重新编程，是将成熟体细胞重新诱导回早期干细胞状态，以用于发育成各种类型的细胞。

Final approval from the ministry is expected next month, according to the British scientific journal Nature.

据英国科学杂志《自然》报道，日本文部科学省预计将于下月正式批准这一实验。

According to Asahi, researchers will take fertilized eggs from rodents that have been gene-edited to remove the ability to produce a pancreas themselves. To this, they will add human iPS cells to create hybrid animal-human embryos.

据《朝日新闻》报道，研究人员将从经过基因编辑的啮齿动物身上提取受精卵，以去除自身发育胰腺的能力。在此基础上，他们将添加人类的iPS细胞来创造人兽杂交胚胎。

These in turn would be implanted into a host animal, in this case a rat or mouse, and allowed to grow.

之后，这些胚胎将被植入宿主动物体内，在这项实验中是一只老鼠，并得以生长。

According to researchers, the goal of the experiment is to create organs viable for transplant into humans.

据研究人员称，这项实验的目标是创造出可以移植到人体的器官。

"Finally, we are in a position to start serious studies in this field after 10 years of preparation," said Hiromitsu Nakauchi, a researcher at the Institute of Medical Science of the University of Tokyo, according to Asahi.

据《朝日新闻》报道，东京大学医学研究所的研究员中内启光说:“经过10年的准备，我们终于可以开始在这一领域进行严肃的研究。”

"We don't expect to create human organs immediately, but this allows us to advance our research based upon the know-how we have gained up to this point."

“我们没有期望能立即制造人体器官，但这让我们能够基于目前所掌握的技术推进研究。”

know-how['nəuhau]：n.诀窍；实际知识；专门技能

Japan had previously banned such experiments.

日本此前曾禁止此类实验。

It reversed its decision in March of this year after consulting with experts.

今年3月，在咨询了专家后，日本政府改变了决定。

The government has said that experiments like these can take place as long as researchers take steps to prevent the birth of a creature that contains a mix of animal and human genetics.

日本政府曾表示，只要研究人员采取措施防止人兽杂交动物的诞生，这样的实验就可以进行。

Researchers will also monitor the animal-human hybrids once they are born for up to two years and will suspend the experiment if they detect that brains inside the growing animals contain more than 30% human cells, Asahi said.

《朝日新闻》称，在分娩后，研究人员还将对人兽杂交动物进行长达两年的监测，如果他们发现这些发育中的动物大脑中含有超过30%的人类细胞，将暂停这项实验。

While other countries have experimented on creating human-animal embryos, Japan is now the first country to support experiments that will allow the animals with human cells to come to full term.

虽然其他国家也开展过创造人兽杂交胚胎的实验，但日本目前是首个支持这项实验，允许胚胎发育到足月分娩的国家。

full term：足月，妊娠期满

Scientists in the US have experimented with pig-human hybrid fetuses and allowed them to develop for three to four weeks before destroying them, as required by US ethics regulations.

根据美国伦理法规的要求，美国科学家对猪与人的杂交胚胎进行了实验，并让它们发育三至四周，然后将其销毁。

But according to Jun Wu, a biologist at the Salk Institute in La Jolla, California, only about 1 in 100,000 cells in the fetuses were human.

但据加州拉荷亚索尔克研究所的生物学家吴军（音译）说，胚胎中只有大约十万分之一的细胞是人类细胞。

In the UK, scientists at King's College London, Newcastle University, and Warwick University created dozens of hybrid embryos that were used to create embryonic stem cells that could potentially treat a wide range of illnesses.

在英国，伦敦国王学院、纽卡斯尔大学和华威大学的科学家们创造了数十个杂交胚胎，用于制造胚胎干细胞，这些干细胞有可能治疗多种疾病。

Concerns about the ethical implications of such research remain.

人们一直担忧这类研究的伦理影响。

Some bioethicists are disturbed by the possibility that human cells implanted into animals may behave unexpectedly, and could affect an animal's brain or cognition.

一些生物伦理学家担心，植入动物体内的人类细胞可能会出现意料之外的反应，并可能影响动物的大脑或认知。

"It is problematic, both ethically and from a safety aspect, to place human iPS cells, which are still capable of transforming into all types of cells, into the fertilized eggs of rats and mice," said Jiro Nudeshima, a researcher specializing in the ethical implications of life science research, according to Asahi.

《朝日新闻》报道称，生命科学研究伦理问题研究员Jiro Nudeshima说：“将仍然能够转换成所有类型细胞的人类iPS细胞植入老鼠的受精卵，这在伦理和安全方面都有问题。”

一些网友也表示并不能接受：

   也有一些网友表达了支持：

  Nakauchi, the researcher proposing the experiment, dismissed concerns, saying that his experiments are focused on the creation of specific organs, and not the development of a new species.

提出这一实验的研究员中内启光反驳了人们的担忧，称他的实验关注的是特定器官的创造，而不是新物种的培养。

"We are trying to do targeted organ generation, so the cells go only to the pancreas," he said, according to Nature.

据《自然》杂志报道，他说:“我们正在尝试培育特定的器官，这样细胞就只能到达胰腺。”

He added that in his previous experiments, the number of human cells inside of a sheep embryo has been extremely small.

他补充说，在他之前的实验中，绵羊胚胎中的人类细胞数量非常少。

"The number of human cells grown in the bodies of sheep is extremely small, like one in thousands or one in tens of thousands," he said, according to Asahi.

据《朝日新闻》报道，他说:“绵羊体内生长的人体细胞数量非常少，只有数千分之一或数万分之一。”

"At that level, an animal with a human face will never be born," Nakauchi said.

他说：“在这个水平上，是不会生出长着人脸的动物的。”