Sperm differentiation in the sea urchins Arbacia punctulata and Strongylocentrotus purpuratus.
D000818:Animals; D002454:Cell Differentiation; D002467:Cell Nucleus; D004447:Echinodermata / Q000254:growth & development*; D005854:Germ Cells / Q000166:cytology / Q000254:growth & development*; D006056:Golgi Apparatus; D008297:Male; D008853:Microscopy; D008854:Microscopy, Electron; D008928:Mitochondria; D013094:Spermatozoa / Q000166:cytology*