title: Fasciola gigantica: histology of the digestive tract and the expression of cathepsin L.
abstract: The digestive tract of Fasciola gigantica is composed of the oral sucker, buccal tube, pharynx, esophagus, and caecum. The tegumental-type epithelium lines the first four parts of the digestive tract while the caecal-type epithelium lines the remaining parts from the caecal bifurcation. The caecal-epithelial cells are classified into 3 types according to their staining properties and ultrastructural characteristics, as related to the amount of food contents in the caecal lumen. All caecal-type epithelial cells synthesize and secrete cathepsin L, a major group of enzymes in the digestive tract, as detected by in situ hybridization and immunolocalization. Moreover, the secreted cathepsin L is also adsorbed on the outer surface of the tegument and the glycocalyx coating of the surface of the tegument, whereas the tegumental cells and tegumental syncytium covering the parasite's body and lining the proximal part of the digestive tract exhibit no in situ hybridization signal and immunostaining for cathepsin L.
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, Thailand.
authors.forename: Krai
authors.initials: K
authors.lastname: Meemon
authors.forename: Witoon
authors.initials: W
authors.lastname: Khawsuk
authors.forename: Sompong
authors.initials: S
authors.lastname: Sriburee
authors.forename: Ardool
authors.initials: A
authors.lastname: Meepool
authors.forename: Manussabhorn
authors.initials: M
authors.lastname: Sethadavit
authors.forename: Veerawat
authors.initials: V
authors.lastname: Sansri
authors.forename: Chaitip
authors.initials: C
authors.lastname: Wanichanon
authors.forename: Prasert
authors.initials: P
authors.lastname: Sobhon
mesh_terms: D000818:Animals; D056668:Cathepsin L / Q000096:biosynthesis / Q000235:genetics*; D002417:Cattle; D005209:Fasciola / Q000033:anatomy & histology* / Q000201:enzymology / Q000235:genetics; D005455:Fluorescent Antibody Technique; D041981:Gastrointestinal Tract / Q000033:anatomy & histology / Q000648:ultrastructure; D015971:Gene Expression Regulation, Enzymologic; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D046529:Microscopy, Electron, Transmission; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D056668:Cathepsin L