来自《耶鲁大学开放课程：生物医学工程探索第6集第6集》

One result of this asymmetrical division

这种不对称分裂的一个结果
is a committed progenitor cell.

是产生定向的祖细胞
The result is a cell that's very similar

另一个结果就是产生一个
but it is - very similar to the progenitor cell

很像祖细胞的细胞
but it's exactly the stem cell.

但却是如假包换的干细胞
So this stem cell division leads to another stem cell

这种细胞分化不仅产生一个定向祖细胞
as well as a committed progenitor cell.

还会产生另一个干细胞
Now, the differences here may be subtle

干细胞与祖细胞化学成分的区别
in terms of chemical composition

还非常微小
or if you put these cells under a microscope

除非你把细胞放在显微镜下
and looked at their analysis.

或者看细胞分析报告
In terms of function they're very important

但就功能而言这些干细胞则至关重要