part_of part of part of preceded by preceded by preceded_by occurrent embryo stage part embryo stage life cycle stage cleavage stage blastula stage OpenCyc:Mx4rEetFnKP2EdqAAAACs4vPlg http://upload.wikimedia.org/wikipedia/commons/c/c6/Blastulation.png OGES:000003 BILS:0000108 consider adding a preceding stage 'morula stage' as part of cleavage WBls:0000005 BilaDO:0000007 UBERON:0000108 uberon ZFS:0000045 Wikipedia:Blastula XAO:1000003 HsapDv:0000006 An early stage of embryonic development in animals. It is produced by cleavage of a fertilized ovum and consists of a spherical layer of around 128 cells surrounding a central fluid-filled cavity called the blastocoel. The blastula follows the morula and precedes the gastrula in the developmental sequence. OGES:000016 EFO:0001282 MmusDv:0000007 OGES:000021