What's a physical mechanism that could lead to differences between these two cells at this very early stage of development?

什么样的生理机制导致细胞,在发育伊始就产生这些差异

耶鲁公开课 - 生物医学工程探索课程节选

Depriving him of the breast, could lead to serious problems in his personality development.

过早断奶，会对他的人格发展造成严重影响。

耶鲁公开课 - 心理学导论课程节选