Ultrastructure of the gravid uterus of Hymenolepis diminuta (Platyhelminthes: Cestoda).
The fine structure of the uterus in gravid proglottids of Hymenolepis diminuta was examined by standard techniques for scanning and transmission electron microscopy. The uterus consisted of a syncytial uterine epithelium attached to the medullary parenchyma through a thin extracellular basal matrix. The epithelium contained prominent nuclei in the juxtalumenal cytoplasm. The cytoplasm was dominated by extensive granular endoplasmic reticulum, with dilated cisternae containing an electron-lucent material and widely scattered electron-dense spherical bodies. No Golgi body or other agranular endomembrane component was observed, but the epithelium contained numerous free ribosomes and a few mitochondria. The apical plasma membrane was folded into long microlamellae. Epithelial and epitheliomesenchymal folds and villi resulted in a compartmentalized uterine lumen, with each chamber containing 1 to several eggs. These data suggest a high level of synthetic activity within the uterine epithelium, but the chemical products and functional significance of this activity are not yet known.
Conn
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Department of Biology, University of the South, Sewanee, Tennessee 37375.
D000818:Animals; D005260:Female; D006926:Hymenolepis / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D014599:Uterus / Q000648:ultrastructure