part_of part of immediately preceded by starts_at_end_of occurrent blastula embryo Ce 1-cell embryo Ce fertilized egg WBls:0000006 worm_development Also called zygote. -50min till 0min of first cleavage at 20 Centigrade. Contains 1 cell. 1-cell embryo unfertilized egg Ce C. elegans life stage occurring during blastula embryo C. elegans life stage by number of cells