The addition of sugar to cell wall polysaccharides and proteins is mainly catalyzed by glycosyltransferases (GTs). Plant O-fucosyltransferases (O-FuTs) are a type of GTs that catalyze fucose transfer from the donor, guanosine diphosphate fucose (GDP-Fuc), to various acceptor molecules, including oligosaccharides, glycoproteins and glycolipids. Previous microarray analysis identified a group of genes that were highly expressed in embryogenic B. napus microspore culture cells in as early as 3 days after microspore embryogenesis induction. Of special interest was the Brassica transcript homologous to the Arabidopsis gene AT2G44500 since it was consistently upregulated (threefold increase) in embryogenic cells compared to pollen-like/non-responsive cells. This Arabidopsis gene contains a GDP-O-fucosyltransferase (O-FuT) domain. In the present study, the complete genomic and coding sequences of At2G44500 homologs were isolated and sequenced from B. napus cv. Topas. Sequence analyses of At2G44500 and its B. napus homolog, BnAt2G (1) suggest that they encode type II-membrane proteins that contain conserved key amino acids essential for O-FuT catalytic activity. BnAt2G(1)/At2G44500 are differentially expressed throughout plant development. In particular, At2G44500 was shown to be highly expressed in the shoot apical meristem (SAM) and young vegetative tissues in A. thaliana. BnAt2G(1) was also shown to be expressed at higher levels in B. napus embryogenic microspore cultures as well as in vegetative tissues. The putative transcription control elements identified in the in silico promoter analysis of At2g44500/BnAt2G(1) suggest that their gene expression is controlled by various transcription factors that are involved in hormone-regulated stress responses. At2G44500 has also been shown to be co-expressed with genes that have known functions in cell wall biosynthesis, embryogenesis and signal transduction. The sub-cellular localization of a GFP