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Carnegie Stage   Figure

High power LM of section through the fertilization cone

High power LM of section through the fertilization cone

A series of six high power LMs of sections through a stage 1a embryo in vitro showing telophase II of the second polar body, 3 hours post-insemination.

e) Formation of the second polar body next to the first is evident (original magnification x460). The second polar body shows extruded chromatin, the telophase II spindle and a dense interbody at the level of the cytoplasmic constriction (arrow). Many sperm heads are in the outer part of the zona pellucida.

From: Lopata et al., 1980. Reproduced with permission of the American Society for Reproductive Medicine.


Keywords: chromatin, cytoplasmic constriction, dense interbody, first polar body, second polar body, sperm head, stage 1a embryo, telophase II, telophase II spindle, zona pellucida


Source: The Virtual Human Embryo.