Structural changes of the chromatin in early development of sea urchins.
D000818:Animals; D002467:Cell Nucleus / Q000166:cytology*; D004447:Echinodermata / Q000196:embryology; D005260:Female; D005306:Fertilization; D006579:Heterozygote; D008854:Microscopy, Electron; D010063:Ovum / Q000166:cytology*; D012728:Sex Chromatin