Gastropods have an extraordinary glycosylation potential with some uncommon carbohydrate modifications, such as methylation and ß1,2-xylosylation. The latter glycan feature occurs typically in plants, but is very uncommon in the animal kingdom. For this reason, the ß1,2-xylosyltransferase (ß1,2-XylT; EC 22.214.171.124) was one desired enzyme to characterize the first time from gastropods. However, creation of expression cDNA libraries in insect cells and subsequent cell sorting procedures, based on ß1,2-xylosylated N-glycans exposed on the cell surface, did not result in the isolation of a snail ß1,2-XylT gene. In addition, homology-based PCR and biochemical purification failed the isolation of the first ß1,2-XylT from gastropods. Based on previous studies, gastropods synthesize mucin-type O-glycans, which play important roles in host finding processes, such as between S. mansoni and B. glabrata. In this study the initiating enzyme, a polypeptide Nacetylgalactosaminyltransferase (ppGalNAcT; EC 126.96.36.199), was identified and characterized. By homology-based PCR and subsequent RACE PCR(s) the fulllength gene of this enzyme from B. glabrata could be isolated from a cDNA library, which was created in this work. This study represents the first recombinant expression and fully characterization of this enzyme family from mollusk kingdom. According to its structure and its substrate specificity it is a close relative to ppGalNAcT-2 isoforms from other animal species. Furthermore, the core-1 ß1,3-galactosyltransferase (core-1 ß1,3-GalT or T-Synthase; EC 188.8.131.52) responsible for the synthesis of the core-1 O-glycan (T-antigen), was isolated to almost 50% from the B. glabrata cDNA library. Using homology-based PCR and a subsequent RACE PCR, the complete 5end was identified and showed characteristics of a type II membrane protein, as well as had high homology to Tsynthases from other organisms.