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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.

f) The entire telophase II spindle with chromatin at both ends is evident (original magnification x947). The maternal (female) pronucleus is forming at the cytoplasmic end of the spindle. The interbody is located at the equator of the spindle. The outer surface of the second polar body shows a dense band of microfilaments (arrow). Sperm heads are present 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, equator of the spindle, fertilization cone, interbody, microfilament(s), pronucleus, second polar body, sperm head, spindle, stage 1a embryo, telophase II, zona pellucida


Source: The Virtual Human Embryo.