The Dynamic Change And Regulation Of Primary Cilia During Mouse Implantation And Decidualization

As an ancient organelle,primary cilia can sense the stimulation of many factors in the external environment,transmit the signal to the cell,and then make the cell respond accordingly.Embryo implantation and decidualization is an indispensable link in the process of embryo development.In this study,immunofluorescence and cell culture were used to explore the dynamic change and regulation of primary cilia in mouse endometrium by using primary ciliary membrane protein Arl13 b as a specific marker of primary cilia.primary cilia exist in mouse endometrial stromal cells rather than epithelial cells,showing a spatiotemporal expression during mouse embryo implantation and decidualization.On days 1 and2 of pregnancy,the cilia length is short.On day 3,the primary cilia in the stromal cells in the subluminal epithelium of the mice instantly lengthened.In the morning on day 4,the length of the primary cilia becomes shorter again.In the evening of day4 when embryo implants,primary cilia are further shortened.No primary cilia are found at embryo implantation sites.During the process of decidualization,primary cilia are present in the decidual area,and gradually lengthen.On day 8,primary cilia are detected in the secondary decidual zone and become longer.The length of primary cilia in endometrial stromal cells of ovariectomized mice is inhibited by high dose of estrogen for 12 h When variectomized mice were treated with progesterone for 3 days,the length of primary cilia is gradually lengthened,and some primary cilia appear in the glands.pregnant mice are treated with a high dose of estrogen in the morning of day 4,primary cilia are significantly shortened,indicating that the appropriate length of primary cilia is beneficial for embryo implantation.When mice aretreated with a high dose of progesterone on day 3 the length of primary cilia becomes longer.Compared to delayed implantation,the length of primary cilia in the subluminal stromal cells is longer than that in delayed implantation.During decidualization,the length of primary cilia is increased gradually by progesterone.In conclusion,primary cilia show a dynamic change in mouse uterus during early pregnancy and is mainly stimulated by progesterone.