Mucus-Secreting Cells from the Alimentary Canal ofCiona Intestinalis

Abstract

The secretion of mucus has been most intensively studied in goblet cells and mucous salivary gland cells from mammals, particularly laboratory rodents. It was therefore thought desirable to characterize mucous cells from the gut ofCiona intestinalis(L.), in which mucus has an important role in food capture, the formation of a food chain, the protection of the gut lining from physical and chemical abrasion and the formation of faeces. The alimentary canal ofCionais composed of five regions: (I) a perforated pharynx, (II) a short tapering oesophagus, (III) an ovoid ridged stomach, (IV) an intestine and (V) a rectum. Previous authors (Roule, 1884; Yonge, 1925; Van Weel, 1940; Millar, 1953; Fouque, 1954) have described the preponderance of mucus-secreting cells which occur in the oesophagus, intestine and rectum. It is these three regions that have now been studied in more detail, with the use of histochemical and electron-microscopic techniques.