The neurons of dorsal root ganglia (DRG) mediate several sensation modalities. The carbohydrate antigens on DRG neurons differ with the sensation modalities that subsets of neurons convey. Despite the important roles of gangliosides and glycoproteins in neuronal differentiation and neuritogenesis of the mammalian nervous system, little is known about the mechanisms underlying the regulation of glycosylation. We previously demonstrated the expression of H-blood type antigens (Fuc alpha1, 2Gal beta) on rabbit DRG neurons of small diameter and dramatic changes in H antigens during the perinatal period. To investigate the possible biological roles and regulatory mechanisms of H antigens, we recently cloned three types of rabbit alpha1,2-fucosyltransferase gene that catalyze the biosynthesis of H antigens. Here, we analyze the expression of these genes, RFT-I, II, and III, in rabbit DRG. The H-type alpha1,2-fucosyltransferase gene, RFT-I, was expressed in DRG in late embryos to adult rabbits, as detected on northern blotting. The other two secretor-type alpha1,2-fucosyltransferase genes, RFT-II and III, were observed to be expressed in late embryonic DRG on RT-PCR analysis but were not detectable on northern blotting. The expression of the H-type alpha1,2-fucosyltransferase gene was analyzed by in situ hybridization and was found to be abundant in small-diameter DRG neurons. These results indicate that the H-type alpha1,2-fucosyltransferase gene plays a major role in the regulation of the H antigen expression in DRG during the perinatal period.