title: The role of astral rays in early cleavage of sea urchin eggs.
mesh_terms: D000818:Animals; D002455:Cell Division; D005260:Female; D005306:Fertilization; D008870:Microtubules / Q000502:physiology*; D008954:Models, Biological; D010063:Ovum / Q000166:cytology / Q000254:growth & development*; D012617:Sea Urchins