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Carnegie Stage   Figure

Cell membrane during the cortical reaction

Cell membrane during the cortical reaction

Very high power TEM of the cell membrane of a stage 1a embryo in vitro, 24 hours after insemination (original magnification x70,000). Notice simultaneous exocytosis of a cortical granule and formation of micropinocytotic caveolae (arrowheads). The cell membrane of the embryo is dense and has a striated appearance in this region. A mitochondrion (M) is closely associated with elements of the smooth endoplasmic reticulum (S).

ZP = zona pellucida

From: Sathananthan and Trounson, 1982. Reproduced with permission of the publisher, John Wiley & Sons.


Keywords: cell membrane, cortical granule(s), exocytosis, micropinocytotic caveolae, mitochondria, smooth endoplasmic reticulum, stage 1a embryo, zona pellucida


Source: The Virtual Human Embryo.