Developmental patterns of mST3GalV mRNA expression in the mouse: In situ hybridization using DIG-labeled RNA probes

mST3GalV synthesizes ganglioside GM3, the precursor for simple and complex a- and b- series gangliosides, and the expression and regulation of mST3Cal V (CMP-NeuAc: lactosylceramide alpha2,3-sialyltransferase) activity is cent ral to the production of almost all gangliosides, a class of glycosphingoli pids implicated in variety of cellular processes such as transmembrane sign aling, synaptic transmission, specialized membrane domain formation and cel l-cell interactions. To understand the developmental expression of mST3GalV in mice, we investigated the spatial and temporal expression of mST3GalV m RNA during the mouse embryogenesis [embryonic (E) days; E9, E11, E13, E15] by in situ hybridization with digoxigenin-labeled RNA probes. All tissues f rom E9 and E11 were positive for mST3CalV mRNA. On E13, mST3CalV mRNA was e xpressed in various neural and non-neural tissues. In contrast to these, on E15, the telencephalon and liver produced a strong expression of mST3Gal V which was a quite similar to that of E13. In this stage, mST3GalV mRNA was also expressed in some non-neural tissues. These data indicate that mST3Ga lV is differently expressed at developmental stages of embryo, and this may be importantly related with regulation of organogenesis in mice.