Glycosyltransferases play an important role in the synthesis of glycoproteins. Here we report the isolation of a brain cDNA coding for 89% of the porcine UDP-N-acetylglucosamine:alpha-6-D-mannoside-beta-1,2-N-acetylglucosaminy ltransferase II (EC 2.4.1.143) (GnTII). The cDNA was used for screening a genomic liver DNA library and isolation of a recombinant lambda FIX II phage containing the complete porcine GnTII gene and upstream and downstream sequences. The beta-1,2-N-acetylglucosaminyltransferase II gene harbours a single exon with an open reading frame of 1338 bp coding for a 446 amino acid protein with a calculated molecular mass of 51.1 kDa. The promoter of the GnTII gene is lacking a TATA-box and shows variable transcription start sites. In the 3'-untranslated region a polymorphic polyadenosine stretch was detected. The porcine GnTII gene contains four polyadenylation sites. PCR analysis of a porcine-rodent hybrid cell panel revealed the chromosomal location of the GnTII gene on SSC 1q23-q27. The mapping data of the cell panel were confirmed by fluorescence in situ hybridization (FISH) on metaphase chromosomes.