Glycopattern analysis of acidic secretion in the intestine of the red-eared slender turtle; Trachemys scripta elegans (Testudines: Emydidae). Issue 5 (October 2017)

• Record Type: Journal Article
• Authors: Scillitani, Giovanni; Mentino, Donatella; Mastrodonato, Maria
• Is Part Of: Tissue & cell. Volume 49:Issue 5(2017)
• Page Start: 573
• Page End: 581
• Publication Date: 2017-10
• Subjects: Testudines -- Trachemys scripta elegans -- Intestine -- Acidic glycans -- Lectin histochemistry; Cytology -- Periodicals; 571.5
• DOI: 10.1016/j.tice.2017.07.004
• Languages: English
• ISSNs: 0040-8166

Abstract

Graphical abstract: Highlights: The secretion of the intestine of Trachemys scripta elegans was studied by histochemical and lectin-histochemical methods. The intestine can be divided in a duodenum, a small intestine and a large intestine. Secreted glycans are sulfosialomucins with fucose, mannose, glucosamine and subterminal galactose/galactosamine residues. Quantitative differences in glycosylation exist both between different tracts and between apex and base of a same villus. The intestine has a complex secretion in contrast to its relatively simple anatomical organization. Abstract: The secretion of the goblet cells in the intestine of Trachemys scripta elegans was studied in situ by histochemical methods to analyze the diversity of sugar chains, with particular regard to the acidic glycans. Conventional histochemical stains (Periodic acid-Schiff, Alcian Blue pH 2.5, High Iron Diamine) and binding with ten FITC-labelled lectins combined with chemical and enzymatic pre-treatments were used to characterize the oligosaccharidic chains. The intestine can be divided into three regions, i.e. a duodenum, a small intestine and a large intestine. Goblet cells were observed in all the three tracts and presented an acidic secretion. WGA, LFA, PNA and SBA binding was observed only after desulfation. Glycans secreted by the three tracts consist mainly of sulfosialomucins with 1, 2-linked fucose, mannosylated, glucosaminylated and subterminal galactosyl/galactosaminylated residuals. Differences among tracts are quantitative rather than qualitative, with sulfated, galactosaminylated and glycosaminylated residuals increasing from duodenum to large intestine, and galactosylated and fucosylated residuals showing an opposite trend. Variation is observed also between apices and bases of villi in both duodenum and small intestine, where sulphation decreases from the base to the apex and glycosylation shows an opposite trend. Functional implication of these findings is discussed in a comparative context.