title: Ultrastructural observations on membranous structures in developing mouse oocytes.
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation; D002467:Cell Nucleus; D005260:Female; D008540:Meiosis; D051379:Mice / Q000196:embryology*; D008854:Microscopy, Electron; D010063:Ovum / Q000166:cytology*