title: Ultrastructural changes in the spermatid nuclear envelope of Periplaneta americana during spermiogenesis.
mesh_terms: D000818:Animals; D002467:Cell Nucleus; D003058:Cockroaches / Q000166:cytology*; D005613:Freeze Etching; D005854:Germ Cells / Q000166:cytology*; D008297:Male; D008566:Membranes; D008675:Metamorphosis, Biological; D008854:Microscopy, Electron; D009758:Nymph; D013091:Spermatogenesis