A 'posterior ring' in the spermatozoa of species of Muridae.
D000818:Animals; D002244:Carbon; D002467:Cell Nucleus; D004822:Epididymis / Q000166:cytology; D008297:Male; D051379:Mice; D008854:Microscopy, Electron; D051381:Rats; D012377:Rodentia; D013094:Spermatozoa / Q000166:cytology*
D002244:Carbon