The sialyl Lewis x (NeuAcalpha2-3Galbeta1-4(Fucalpha1-3)GlcNAc) determinants serve as ligands in the selectin-mediated adhesion of leukocytes to activated endothelium. The final step in the sialyl Lewis x synthesis is catalyzed by alpha1-3-fucosyltransferase, which transfers fucose to sialylated type 2 chain. We report the cloning of rat alpha1-3-fucosyltransferase gene (rFUT) isolated from rat lymph node and kidney allograft. The rFUT is expressed as two splice variants, but only the long one showed enzymatic activity towards sialylated lactosamine. Also flow cytometry analysis with the sLex mAbs indicated that the cloned rFuc-T was a functional enzyme and a member of the Fuc-TVII family. The rFuc-TVII mRNA expression level was strongly enhanced during acute inflammatory reaction induced by kidney allograft rejection, which could be detected by in situ hybridization and quantitative real-time PCR.