Scientists produced healthy offspring from the cells of another species for the first time by taking rat stem cells involved in sperm production and implanting them in mice testicles.

• 美国科学家今年早些时候利用老鼠胚胎干细胞首次培育出具有繁殖能力的精子，并利用其培育出老鼠胚胎。此项成果有望为繁育牲畜和其他濒临灭绝的动物开拓一条新道路。