LM of a stage 2 embryo on day 4 in vitro showing closely opposed cell membranes (compaction 4). The morula entered compaction at 6-8 blastomeres. Further cell divisions were inhibited until compaction was completed.
From: Veeck and Zaninovic´, 2003. Reproduced with permission of the publisher, Taylor & Francis Group.
Keywords: blastomere cell membrane, blastomere nucleolus, blastomere nucleus, capsula (zona) pellucida, compacting embryo, exterior part of blastomere cell membrane, polar body, subzonal space, zona pellucida
Source: The Virtual Human Embryo.