CHARACTERIZATION OF INTERCELLULAR-JUNCTIONS IN PREIMPLANTATION MOUSE EMBRYO BY FREEZE-FRACTURE AND THIN-SECTION ELECTRON-MICROSCOPY
CHARACTERIZATION OF INTERCELLULAR-JUNCTIONS IN PREIMPLANTATION MOUSE EMBRYO BY FREEZE-FRACTURE AND THIN-SECTION ELECTRON-MICROSCOPY
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DOI：
10.1016/0012-1606(77)90296-2
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发表时间：
1977-01-01
影响因子：
2.7
通讯作者：
STACKPOLE, CW
中科院分区：
文献类型：
--
作者：
MAGNUSON, T;DEMSEY, A;STACKPOLE, CW
在4细胞期，在薄片胚胎的卵裂球之间观察到紧密的膜对置区，膜接触的焦点和偶见的细胞质密度。在冷冻破裂的胚胎中没有观察到相应的膜内特化。在8~16细胞期，冷冻破裂胚胎的卵裂球之间可见小间隙、小斑状闭塞连接及各水平的连接复合体。随着发育从早期到中期的8-16细胞期，闭塞/缝隙连接复合体的大小增加，形成筋膜闭塞/缝隙连接复合体。桑拿期滋养层细胞和内细胞团[ICM]细胞均可见缝隙连接和闭塞/缝隙连接复合体。在冷冻破裂胚胎的假定滋养层细胞上，第一次观察到桑蚕期的闭锁带连接。与早期桑拿期相比，中期具有闭合带连接的胚胎数量增加。在囊胚期，冻裂胚胎和薄片胚胎滋养层细胞之间可观察到由闭锁带、黄斑粘连和缝隙连接组成的连接复合体。在滋养层细胞和ICM细胞上可见孤立的缝隙连接和闭塞连接、黏附连接和闭塞/缝隙连接复合体。
At the 4 cell stage, regions of close membrane apposition with focal points of membrane contact and occasional underlying cytoplasmic densities were observed between blastomeres of thin-sectioned embryos. Corresponding intramembrane specializations were not observed in freeze-fractured embryos. At the 8 to 16-cell stage, small gap and macula occludens junctions and complexes of these junctions were observed at all levels between blastomeres of freeze-fractured embryos. As development progressed from the early to mid 8 to 16-cell stage, the size of the occludens/gap junction complexes increased, forming fascia occludens/gap junction complexes. At the morula stage, gap junctions and occludens/gap junction complexes were observed on both presumptive trophoblast and inner cell-mass [ICM] cells. Zonula occludens junctions were 1st observed at the morula stage on presumptive trophoblast cells of freeze-fractured embryos. The number of embryos possessing zonula occludens junctions increased at the mid compared to the early morula stage. At the blastocyst stage, junctional complexes consisting of zonula occludens, macula adherens and gap junctions were observed between trophoblast cells of freeze-fractured and thin-sectioned embryos. Isolated gap and occludens junctions, adherens junctions and occludens/gap junction complexes were observed on trophoblast and ICM cells.