title: Ultrastructural analysis of nucleolar evolution in the rat primary oocyte.
mesh_terms: D000818:Animals; D002466:Cell Nucleolus; D002467:Cell Nucleus; D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D008540:Meiosis; D008854:Microscopy, Electron; D010063:Ovum / Q000166:cytology* / Q000254:growth & development; D051381:Rats; D013997:Time Factors