The goat embryo re-acted the process of the system evolution, which passed through pronephros, mesonephros and metanephros.

山羊胚胎重新反应了系统进化的过程，该过程通过前肾，中肾和后肾。

youdao

The idea here is that - while Earth formed slowly from planetary embryos colliding - Mars is itself a solitary planetary embryo that formed very early in the history of our solar system.

这里想表达的观点是，当地球从行星胚胎间相互碰撞缓慢形成时，火星却是一个孤独的行星胚胎，在太阳系历史上形成得很早。

youdao

Mesoderm --- The middle germ layer in the early embryo; the source of cells that go on to make bones, muscles, connective tissue, heart, hematopoietic system, kidney, and other organs.

原肠胚形成过程中，由上胚层细胞增殖产生的一部分细胞在上、下胚层之间形成的第三层细胞。通常形成骨骼、肌肉、结缔组织、心脏、造血系统、肾脏和其它器官。

youdao

On occasion, the immune system is primed to attack the embryo because it contains genetic material from the father, which can be interpreted as foreign.

BBC: NEWS | Health | Test to boost IVF success rates

The researchers believe that sHLA-G appears to protect the developing embryo from attack by the mother's immune system.

BBC: NEWS | Health | Test to boost IVF success rates

Professor Alan Beer from Chicago Medical School, says that, in some cases, the problem may be an immune system which turns on the newly-implanted embryo and destroys it.

BBC: Immune treatment 'cuts IVF failures'