中文摘要：

衰老是胚胎发育过程中的一种正常的程序，参与胚胎发育的组织重构、组织发育和形态上发生，属于发育程序性衰老机制。作为不同的细胞过程，衰老与凋亡密切相关。在输尿管发育过程中，凋亡具有重要作用，胚胎肾管（CND）发生正常凋亡使得输尿管日与中肾管（WD）分离并与膀胱上皮融合，维持正常输尿管发育以及与膀胱接口正常。

英文摘要：

Senescence is a normal process in the embryonic development, which is involved in embryonic tissue remodeling, tissue development, and morphogenesis, as a programmed aging mechanism during development. As different cellular processes, senescence and apoptosis are closely related to each other. Apoptosis plays an important role during the ureter development. Apoptosis in common nephric duct （CND） occurs normally during development to make the ureteral orifice separate from Wolffian duct （WD） and then fuse with the bladder epithelium, which leads to normal ureter development.