Lectin binding in normal donkey eyeball

In the present study, the distribution of various sugar residues in the eyeball tissues of sexually mature donkey was examined by employing fluorescein isothiocyanate-conjugated lectins. Our results revealed the presence of mannose (labeled by lectins ConA), galactose (labeled by PNA, GSAI, ECA), GalNAc (labeled by SBA, VVA), and GlcNAc (labeled by WGA) residues in the donkey ocular tissues. The epithelium and stroma of the ocular tissues were labeled with mannose (ConA) and GlcNAc (WGA) binding lectins. Binding sites for WGA and PNA to the rod and cone cells of the retina were evident. The lectins Con A, WGA and GSAI are bound strongly to the endothelium of blood vessels and to smooth muscle cells of the iris. In conclusion, the findings of the present study clearly indicate that the donkey eyeball contains a wide range of glycoconjugates (bearing mannosyl, galactosyl and glucosly residues), and it lacks fucosyl residues.