1817年，在第一次移民大潮中，一位英国游客观察到：“古老的美洲似乎正在分裂并向西移动。”

"Old America seemed to be breaking up and moving westward," observed an English visitor in 1817, during the first great wave of migration.

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美国俄克拉荷马州医学研究基金会的科学家们第一次成功地将细胞分裂的过程加以逆转，这一医学技术上的突破可能会最终使人类获得治愈癌症及其它多种疾病的有效办法。

Now scientists have for the first time reversed the process of cell division, a breakthrough that could eventually lead to treatments for cancer and other disorders.

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结果表明海狸鼠卵母细胞与其它啮齿动物的卵母细胞一样，能够在体外培养成熟，完成第一次减数分裂，排出第一极体。

The results indicated that nutria oocytes, like other rodent oocytes, can be matured in vitro, complete first meiotic division and discharge first polar body.

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In fact, there are differences that can be detected upon the first cell division where this zygote divides through the process of mitosis.

事实上,受精卵在进行,第一次有丝分裂时,就会产生差异

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There's one division, here it shows it at the 16 cell stage and then here, and this transformation as it goes from 16 cells to more like 64 cells.

这是第一次分裂,这里显示的是十六细胞期,然后在这里,在这里胚胎进一步的产生了变化,由十六个细胞分裂为约六十四个

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Potential refers to what it sounds like, 'what potential does this committed progenitor cell have?' 'What potential does this stem cell have?' Well, one way to think about is that upon this first division, this asymmetric division, this committed progenitor cell has lost some potential.

这个"潜能"和字面意思相同,定向祖细胞的潜能是什么,干细胞的潜能又是什么,一种看法就是在第一次分化时,即不对称分裂时,定向祖细胞失去了一些潜能

耶鲁公开课 - 生物医学工程探索课程节选