title: The operculum-plug area and membranous structure of the eggs of Trichuris trichiura.
abstract: Eggs of Trichuris trichiura were prepared for scanning electron microscopy (SEM) by the dimethylsulfoxide freeze-cracking method. The egg-shell and oocyte were examined by SEM. The egg has a chitinous shell which consists of more than 10 layers of dense lamellae. The shell is bordered by a limiting membrane. An operculum and a collar made of chitinous shell together form the opercular area. The operculum is an empty cavity. The chitinous fibers of the egg-shell in this area are diffuse and loose, with numerous micropores or spaces. The egg-shell in this area therefore appears to form a fine tubular network. The oocyte is an undifferentiated cell with a biconcave drum-like shape. The perivitelline space is conspicuous at both ends of the cell.
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010063:Ovum / Q000648:ultrastructure*; D014257:Trichuriasis / Q000209:etiology; D014258:Trichuris / Q000302:isolation & purification / Q000502:physiology*