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Background and Objective: Lectins are carbohydrate-binding proteins of plants or animal origin, which react with terminal sugars of glycoconjugates of cells and tissues. Glycoconjugates play essential role in several biological phenomena such as Cell recognition, proliferation, migration and differentiation. Notochord, a mesodermal derivative, induces nearby tissues, including Neural tube, sometimes and developing gut. Materials and Methods: The purpose of this study was to investigate distribution of glycoconjugates in component of notochord and axial vessels during mouse embryonic development. Results: Formalin fixed sections embedded in paraffin from 9 to 14 embryonic days of Balb/c mice were processed for histochemical studies by using four different horseradish peroxidase (HRP) labeled lectins including: Glycin Max (SBA), Vicia Villosa (VVA) and Maclura Pomifera (MPA) specific for GalNac terminal sugar and Lotus Tetragonolobus (LTA) that bind to ?-L-fucose terminal sugar. Our results revealed that approximately similar reactions were observed in notochord and axial vessels endothelium by using GalNac sensitive lectins during vessels morphogenesis. Fucose sensitive lectin reacted only with the notochord. The time and significant role(s) in tissue interactions and subsequent formation of adjacent tissues such as: Axial vessels development during critical morphogenic period. Conclusion: Furthermore, our findings indicate that fucosylated glycoconjugates may have no role in axial vessel formation and/or their interactions with the notochord during early morphogenic period.

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Background & Objective: The pattern of cell types in vertebrate embryos depend on the function of organizing centers, specialized cell groups that direct the fate of nearby cells through the secretion of inductive factors. Our previous studies showed that during early neural tube formation, the notochord is essential for the induction of ectoderm and for the subsequent differentiations of the neuroepithelium. It is well known that glycoconjugates are developmentally regulated expression on the surfaces of early embryonic cells and could therefore be involved in many critical morphogenetic and histogenetic events during embryonic development. Materials & Methods: In the present study, histochemical studies were carried out to detect the presence and distribution of terminal sugars during development of precursors of motor neurons within the developing spinal cord in balb/c mice. Embryos from day 9 to 14 of gestation were fixed and processed for lectin histochemical studies by using horseradish peroxidase labeled WFA with binding specificity for terminal N-acetylgalactosamine. Results: The first reaction was occurred weakly on the cells surface and extra cellular matrix just around the peripheral portion of floor plate on day 13 of gestation. It seems that these cells are developing premotor neurons, which will form the future motor neurons of the spinal cord. The reaction increased significantly and extended to the deep part of spinal floor plate by day 14. Conclusion: These data indicate that glycoconjugates containing N-acetylgalactosamine may play important roles in differentiation of the floor plate motor neuron and perhaps glia cells in final development of the ventral part of the spinal cord.

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Background&Objective: Carbohydrate chains link to glycoproteins and glycolipids of the cell surface particulary their terminal sugars have key roles in cellular activities of almost all biological systems. Distribution of these glycoconjugates in adult kidney has not received fair attention yet. The purpose of this study was to identify in situ location of galactose – N – acetyle galactoseamine moleucles on the surface of the adult rat kidney. Materials&Methods: After the resection of rat kidney and rotin fixation with regular lectin histochemical technique, MPA and PNA conjugated to horseradish peroxidase, lectins specific to indentify these terminal sugars in rat kidney. Results: Intense reaction of PNA to collective tubules, less intense and reaction with luminal surface of proximal tubules and MPA identified distinct cells among distal tubules as well as glomerules were observed. Conclusion: It seems that this specific sugars related to the cellulars function of this region of adult kidney and probably genetically is regulated during embryonic development.

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Background and Objective: The neurohypophysis originates from the floor of diencephalon. Its development controles by several cellular interactions that mediated by some molecules such as cell surface and extra cellular matrix Glycoconjugates terminal sugars. In this study we used lectin histochemichal technique to evaluate distribution of the Glycoconjugates and their changes during development of neurohypophysis. Materials and Methods: This experimental study carried on 40 female and 20 male adult Rats. After mating and appointment day zero of pregnancy, pregnant Rats were sacrificed from days 10-20 of gestation and their embryos were collected for histochemical study. The serial section of head specimens were fixed and incubated with different HRP-lectins from Orange fungus (OFA) Vicica villosa (VVA), Glycine max (SBA), Wistaria floribunda (WFA), peanut (PNA), Griffonia simplicfolia (GSA1-B4), Lotus tetragonolobus (LTA) and Ulex Europeus (UEA-1). OFA, LTA and UEA-1 lectins are specific for terminal sugars α-L–Fucose and WFA, SBA, VVA and PNA are specific for D-GalNAc, α, ß-D-GalNAc and GalNAc, D-Gal-(ß-1-3)- D-GalNAc of complex glycoconjugates respectively. Results: Our findings demonstrated that the reaction of neurohypophysis cells with OFA initiated from gestational GD10 and increased to GD15 (P<0.05) and then increased to GD17 (P<0.05). A few cells of neurohypophysis reacted with PNA from GD13 to GD16 and decreased afterward (P<0.05). Some cells of neurohypophysis reacted with SBA from GD14 to GD18 and decreased afterward (P<0.05). Reacting of many cells of neurohypophysis with WFA started on GD13 and increased to GD15 (P<0.05) and then decreased afterward (P<0.05). Neurohypophysis cells showed no reaction with the UEA-1, LTA, VVA and GSA1-B4 lectins. Conclusion: The expression of Glycoconjugates with terminal sugars α-L–Fucose, α, ß-D-GalNAc and D- Gal– (ß-1-3)- D-GalNAc have importanct role and special spatiotemporal situation in neurohypophysis development.

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Background and Objective: Different organizers are involved in spinal cord development and differentiation by sending various messages. Specific glycoconjugates secreted from the cells of lateral wall of spinal cord can also act as neurogenesis and neural differentiation messengers. This study was carried out to determine the distribution of sugar compounds in the lateral walls of spinal cord during mice morphogenesis using lectin histochemistry method. Methods: In this experimental study, sections of BALB/c mice from 10-16 embryonic days were fixed in formalin and then histological sections were prepared. Tissue samples for reaction to the glycoconjugates were incubated with DBA, OFA, GSA1B4 and MPA lectins. Alcian blue with pH equal 2.5 was used for background staining. Results: DBA lectin did not react with the lateral wall of the spinal cord. MPA lectin showed severe reaction but consistent, especially in nerve fibers of the lateral wall of spinal cord. GSA1B4 lectin showed weak reaction in the cells and nerve fibers of the spinal cord, but severe reaction was clearly observed in blood vessels. OFA lectin showed severe reaction with α-L-Fucose terminal sugar in the lateral walls of the spinal cord in early stages of morphogenesis. Conclusion: The most reaction in the lateral walls of the spinal cord was related to OFA, which reflects the importance of fucose terminal sugar by connecting (1→6) to the penultimate sugar N-acetyl-D-glocosamin (Glc-Nac) in the development of spinal cord. Due to severe reaction of GSA1B4 to blood vessels of spinal cord, use of this lectin for vascular studies, is recommended.