层粘连蛋白在小鼠胚胎早期发育期间的表达与分布

目的:研究发育不同阶段早期小鼠胚胎中层粘连蛋白(1aminin,LN)的表达与分布变化,以进一步探讨LN与胚胎细胞分化及着床的关系.方法:取植入前发育不同阶段的单个小鼠胚卵,应用免疫荧光间接法和酶免疫组织化学ABC等方法观察早期胚胎中LN的表达时间、强弱及分布状况.结果:从原核期、Ⅱ细胞期至Ⅷ细胞期胚,卵裂球内均可见LN强免疫荧光或棕色LN阳性反应颗粒,卵裂球外间质中LN则为阴性反应.到桑椹胚期,卵裂球内及间质中同时出现LN阳性反应物质.早期胚泡中LN主要分布在内细胞团,滋养层细胞间质中也有分布.晚期胚泡滋养层细胞内LN表达增强,细胞间质中转为阴性,近内细胞团侧的滋养层与内细胞团处,均表达出LN强阳性反应.结论:早期小鼠胚胎的卵裂球中含有LN;桑椹胚期LN在细胞间质中出现;胚泡侵入子宫内膜期间近内细胞团侧的滋养层细胞及内细胞团中的LN含量增加;小鼠早期胚胎中LN与其发育及粘附着床正相关.

Expression and distribution of laminin in the mouse embryos during early development

Objective: To study the expression and distribution of laminin(LN) in the mouse early embryos during the various stages of development. And to inquire further the relationship of LN with embryo differentiation and implantation of blastocyst. Methods: Indirect immunofluorescence technique and immunohistochemical ABC method were used to observe LN in mouse early embryos during the various stages of development. Results: Strong immunofluorescence or brown granules for LN staining were found in the blastomere of pronucleus stage, two cell to eight cell stage, but not in the extracellular matrix. In morula, positive LN immunoreactive substance appeared simultaneously in both blastomere and extracellular matrix. LN chiefly distributed in the inner cell mass and between trophoblasts in early blastocyst. When it was later blastocyst, LN expression was enhanced in trophoblast cells, but not in the extracellular matrix. And strong positive LN immunoreactive substance was also found in the inner cell mass and polar trophoblast cells. Conclusion: LN existed in the blastomere during early mouse embryo development; LN appeared in extracellular matrix in morula; LN in the polar trophoblast cells and inner cell mass increased when blastocyst intruded into endometrium; LN in early mouse embryos was related to embryo development, attachment and implantation.