科學家將一只老鼠基因改造成4%的人類

科學家將一只老鼠基因改造成4%的人類

Scientists mixing the genetic building blocks of two different animal species sounds like the beginning of a bad science fiction movie, but that’s precisely what a team of researchers just did by injecting human stem cells into mouse embryos. Just over two weeks later, the team had more mature mouse embryos that contained up to four percent human cells.

科學家們將兩種不同動物的基因構建塊混合在一起，聽起來像是一部糟糕的科幻電影的開始，但這正是一個研究小組剛剛通過將人類干細胞注入小鼠胚胎所做的。僅僅兩周后，研究小組就有了更成熟的小鼠胚胎，其中含有高達4%的人類細胞。

These cross-species hybrids, called chimeras, were long the stuff of fiction but have more recently become reality. Scientists in several countries have conducted experiments in which human cells were added to developing animal embryos, but none of them have managed to create an animal that was made up of as many human cells as these mice.

這些被稱為嵌合體的跨物種混血兒長久以來都是虛構的，但最近才成為現(xiàn)實。有幾個國家的科學家進行了實驗，將人類細胞添加到發(fā)育中的動物胚胎中，但沒有一個國家能夠創(chuàng)造出像這些老鼠那樣由人類細胞組成的動物。

As ScienceNews reports, the researchers modified the human stem cells by tweaking a protein and bringing the cells back to a previous stage in their development. This may be what allowed the cells to conform to their new surroundings after being injected into the mouse embryos.

據《科學新聞》報道，研究人員通過調整一種蛋白質，使干細胞恢復到其發(fā)育的前一階段，從而對人類干細胞進行了改造。這可能是使細胞在注入小鼠胚胎后能夠適應新環(huán)境的原因。

After letting the embryos develop for a further 17 days, the scientists discovered that human cells had spread throughout much of the developing animal. Human cells were found in tissue that would form the heart and brain and were especially plentiful in the blood. Not all of the embryos developed in the same manner and some had human cells in places where others didn’t, such as the eyes.

在讓胚胎繼續(xù)發(fā)育17天后，科學家們發(fā)現(xiàn)人類細胞已經擴散到了大部分發(fā)育中的動物身上。人類細胞存在于心臟和大腦的組織中，在血液中尤其豐富。并不是所有的胚胎都是以同樣的方式發(fā)育的，有些胚胎在其他胚胎不發(fā)育的地方有人類細胞，比如眼睛。

But why do any of this at all? The idea here isn’t to create human/animal hybrids simply for the sake of doing so. It may seem a lot like “playing God,” but the scientists have human lives on their minds. It’s thought that if the development of these hybrid animals reaches a certain level of maturity, the animals could play a dramatic role in the testing of life-saving treatments that could ultimately be used on humans. It’s even possible that specific animals, like pigs, could one day grow human organs, thus offering doctors a new source of healthy organs for use in transplants.

但為什么要這樣做呢?這里的想法并不是簡單地為了這樣做而創(chuàng)造人類/動物雜交。這聽起來很像“扮演上帝”，但科學家們的頭腦中有人類的生命。人們認為，如果這些雜交動物的發(fā)育達到一定程度的成熟，這些動物就可以在測試拯救生命的治療方法中發(fā)揮重大作用，最終可以用于人類。甚至有可能某些特定的動物，比如豬，有一天能夠長出人體器官，從而為醫(yī)生提供用于移植的健康器官的新來源。

That, of course, is the scientific side of things. The ethics of it all are another story entirely. It’s easy for us to say that a human life is more valuable than that of any random animal, but the idea of raising farms of human/animal hybrids just so we can yank their guts out and slap them into our own bodies is a little, well, uncomfortable to think about.

當然，這是科學的一面。道德方面則完全是另一回事。我們很容易說，人的生命比任何隨機動物的生命都更有價值，但養(yǎng)人獸雜交農場的初衷，只是為了讓我們能把它們的內臟抽出來，然后把它們放到我們自己的身體里，是有點，嗯，不舒服。

In any case, we’re certainly not there yet and while the four percent human mouse is a step in that direction, there’s plenty of more work to be done.

無論如何，我們肯定還沒有達到這個目標，雖然4%的人類老鼠是朝著這個方向邁出的一步，但還有大量的工作要做。