ISSN:
1432-0878
Keywords:
Nidation
;
Mice
;
Cell interaction
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The interaction between the trophoblast and the maternal epithelium at early implantation was studied by means of light and electron microscopy. The uterine horns were fixed in situ and a double-embedding method was used to locate implantation sites. Observations were made on mice killed at 2 hour intervals 90–116 h. post coitum which covered the following stages: pre-attachment (i) with zona pellucida intact (ii) with zona pellucida in dissolution (iii) after loss of the zona; attachment; adherence; and invasion. The intact zona pellucida was electron opaque and of uniform density. In the stage of apparent dissolution it became electron dense and was trapped between trophoblast and epithelium. At preattachment the trophoblast cells were round. Subsequently they became long and attenuated, often with lysosomes in the cytoplasm proximal to the epithelial layer. Epithelial cells, which could be seen in various stages of degeneration were apparently phagocytosed by the trophoblast. Occasional pyknotic epithelial cells were seen, as well as some apparently normal ones which contained cytosegresomes. The possible reasons for their presence are discussed. The microvilli of the epithelial cells changed from regular and pointed at preattachment to short and irregular at adherence and invasion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00218936
