A putativeDrosophilanucleotide sugar transporter was characterized and shown to be theDrosophilahomologue of the human UDP-Gal transporter (hUGT). When the Drosophila melanogasterUDP-Gal transporter (DmUGT) was expressed in mammalian cells, the transporter protein was localized in the Golgi membranes and complemented the UDP-Gal transport de®ciency of Lec8 cells but not the CMP-Sia transport de®ciency of Lec2 cells.