SELF-FERTILIZATION
自体繁殖
Q. I read about some researchers who were trying to produce sperm from bone marrow stem cells. If a woman were to have sperm cells made from her own stem cells and impregnate herself, what would be her relationship to her daughter?
Q．我看到一些研究说，他们正在尝试用人体骨髓干细胞来生产精子。如果一个女性用她自己的骨髓干细胞造出了一个精细胞，并使自己受孕，那么她和她的女儿会是什么关系？
-R Scott LaMorte
——R．斯科特•拉莫尔特
A. TO MAKE A HUMAN, you need to put together two sets of DNA.
A．要想造成一个人类，你需要把两套DNA拼到一起。
In humans, these two sets are held in a sperm cell and an egg cell, each of which holds a random sample of the parents 8217; DNA. (More on how that randomization works in a moment.) In humans, these cells are from two different people. However, that doesn 8217;t necessarily have to be the case. Stem cells, which can form any type of tissue, could in principle be used to produce sperm (or eggs).
对于人类，这两套DNA分别位于精细胞和卵细胞中，其中每一套都是从父母那里随机取出来的一部分DNA。（很快我们会具体讲到这个随机过程。）对于人类，精细胞和卵细胞分别来自两个不同的人，但如果你有能够分化成任何细胞的干细胞的话，事情就不是这样了，理论上来说，干细胞也可以被用来生产精细胞或者卵细胞。
So far, nobody has been able to produce complete sperm from stem cells. In 2007, a group of researchers succeeded in turning bone marrow stem cells into spermatogonial stem cells. These cells are the predecessors to sperm. The researchers couldn 8217;t get the cells to fully develop into sperm, but it was a step. In 2009, the same group published a paper that seemed to claim they 8217;d made the final step and produced functioning sperm cells.
到目前为止，还没有人能够利用干细胞制造出完整的精细胞。2007年一组研究人员成功地将骨髓干细胞转化成了精原细胞，这些细胞是精子的前体。研究人员无法将这些细胞完全转化成精细胞，但这至少是一个进步。2009年，这些研究人员发表了一篇论文，看上去宣称他们已经实现了最后一步，制造出了完整的具有功能的精细胞。
There were two problems.
但是这里有两个问题。
First, they didn 8217;t actually say they had produced sperm cells. They said they produced sperm-like cells, but the media generally glossed over this. Second, the paper was retracted by the journal that published it. It turns out the authors had plagiarized two paragraphs of their article from another paper.
首先，他们并没有说他们制造出了精细胞，而是说制造出了类精子细胞，但媒体在报道时通常都打马虎眼没提。其次，发表论文的期刊撤下了这篇论文，因为其中的两个段落抄袭自其他论文。
Despite these problems, the fundamental idea here is not that far-fetched, and the answer to R. Scott 8217;s question turns out to be a little bit unsettling.
虽然有这样那样的问题，但这个设想本身并非是天方夜谭，斯科特的问题的答案甚至让人有些小激动。