title: An ultrastructural and radioautographic study of early oogenesis in the toad Xenopus laevis.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002466:Cell Nucleolus; D002467:Cell Nucleus; D003593:Cytoplasm; D004247:DNA; D005260:Female; D008540:Meiosis; D008854:Microscopy, Electron; D010063:Ovum / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014981:Xenopus / Q000502:physiology*
chemical_list: D014316:Tritium; D004247:DNA; D013936:Thymidine