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Carnegie Stage   Figure

Cytoplasm and cell junction of a 2-cell embryo

Cytoplasm and cell junction of a 2-cell embryo

TEM of the cytoplasm and cell junction of a stage 2, 2-cell embryo in vitro, 44 hours post-insemination, (original magnification x8,400). Each blastomere has most of the organelles found in oocytes and 1-cell embryos. The blastomeres are closely apposed and the intercellular space contains microvilli that are sometimes aligned longitudinally or interlock with one another. Mictochondria (M), vesicular smooth endoplasmic reticulum (S) and small aggregates of smooth endoplasmic reticulum (A) are distributed randomly in the cytoplasm. Some parts of the vesicular smooth endoplasmic reticulum are dilated and translucent. Large vacuoles (V) are associated with mitochondria.

SS = subzonal space

From: Sathananthan, 1984. Reproduced with permission of the publisher, Elsevier.

Click on the picture to view the full-sized image.


Keywords: blastomere, cell junction, cytoplasm, intercellular space, microvilli, mitochondria, oocyte, stage 2 embryo, subzonal space, two-cell embryo, vacuole(s), vesicular smooth endoplasmic reticulum


Source: The Virtual Human Embryo.