Identification of Extracellular Matrix and Terminal Sugars D-Gal, Gal/GalNac and Sialic Acid in Developing Iris and Ciliary Body.

Glycoproteins and glycoconjugates play an important role in tissue morphogenesis. Development of ciliary body and iris requires mutual interaction between optic cup, neural crest and surrounding mesenchyme. The nature of these interactions is regulated by extracellular matrix and terminal sugars. The aim of the present study was to investigate the presence and distribution of extracellular. matrix and glycoconjugate. In this regard rat embryos from 11 to 20 days of gestation from 30 pregnant rats were collected and vaginal plug was taken as day 0 of gestation.Histochemical staining and lectin histochemistry using (PNA, BSAI-B4, sialidase digestion/pNA method) were carried out on sections with 5-6 micrometer thickness. The presence of Gall GalNac, D-Gal, sialid acid, hyaluronic acid and carboxylated glycosaminoglycan in developing iris and ciliary body was confirmed. The reaction of ciliary body and iris to PNA and S/PNA were increased by embryonic age, while more reaction to BSAI-B4 was noted on the 16th day of gestation. Therefore, it is concluded that, changes of glycoconjugate and extracellular matrix follow a spatiotemporal pattern and reflect the morphological events of tissue differentiation.