[Expression of N-deacetylase/N-sulfotransferase (NDST) during early rat embryogenesis]

Fibroblast growth factors (FGFs) are known to be required for embryonic growth, formation, and shaping of many tissues and organs during embryogenesis. Biochemical studies have indicated that heparan sulfate proteoglycans, which are present on most cell surfaces and in extracellular matrices, play essential roles in FGF binding to its receptors and subsequent signal transduction. N-deacetylase/N-sulfotransferases (NDSTs), which catalyze the first modifying step in the biosynthesis of heparan sulfate, are essential enzymes for the biosynthesis of heparan sulfate. The critical roles of heparan sulfate proteoglycan in developmental processes and specific signaling pathways have been illustrated by the identification of mutations in enzymes involved in the biosynthesis of heparan sulfate in Drosophila and mice. However, null mutation analyses of NDST-1 and NDST-2 have not clarified the embryonic regulation of morphogenesis by NDSTs. In the present study, we examined the temporal and spatial expression of NDST-1, and the temporal expression of NDST-2, in early rat embryogenesis, to investigate the role of NDSTs during embryogenesis. The expression pattern of rat NDST-1 appears to colocalize with certain FGFs and FGF receptors, suggesting possible roles of NDST in embryogenesis.