Expression patterns of complex glycoconjugates and endogenous lectins during fetal development of the viscerocranium

Experimental evidence suggests that carbohydrates and their corresponding receptors (endogenous lectins) decode biological information. Therefore, the expression of complex oligosaccharides — the potential ligand part of this recognition system — during chondrogenesis and osteogenesis was determined in the viscerocranium of fetal rats by mapping the staining patterns of exogenous lectins. Results were compared with the expression of bone- and/or cartilage-specific core proteins and the binding profiles of neoglycoconjugates. These synthetic tools make possible the localization of sugar-ligand-binding sites. The spatial and temporal distribution patterns of glycoconjugates were highly dynamic and demonstrated a clear correlation with characteristic morphological modifications. The glycobiological characterization of precartilage mesenchymal cells revealed distinct differences compared to prospective bone anlagen. Especially the binding of the exogenous lectin from Griffonia simplicifolia II, that selectively visualized prechondral aggregations, reveals that regulation of early chondral growth is at least phenomenologically correlated with a relatively atypical oligosaccharide composition terminating with N-acetylglucosamine.