Fig. 19 Very high power TEM of the junctional complex between two trophoblast cells of a stage 3 embryo in vitro, 145-170 hours post-insemination (original magnification x50,400). The zonal borders of adjacent trophoblast cells are usually sealed by an apical complex composed of a tight junction, desmosome, and gap junction. Less well developed desmosomes and gap junctions are observed between trophoblast and inner mass cells and between neighboring inner mass cells.
D, desmosome; ZP, zona pellucida.
(From: Lopata, Kohlman, and Kellow, 1982. Reproduced with permission of the publisher, John Wiley & Sons.)
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