Diverse spatial expression patterns of UDP-GalNAc : polypeptide N-acetylgalactosaminyltransferase family member mRNAs during mouse development

Cell migration and adhesion during embryonic development are complex proces ses which likely involve interactions among cell-surface carbohydrates, Whi le considerable work has implicated proteoglycans in a wide range of develo pmental events, only limited attention has been directed towards understand ing the 7role(s) played by the related class of mucin-type O-glycans, The i nitial step of mammalian mucin-type O-glycosylation is catalyzed by a famil y of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (ppGaNTases) . The spatial expression patterns of the messenger RNAs of seven ppGaNTase family members were investigated from gastrulation through organogenesis st ages of mouse development. The seven glycosyltransferases were expressed in unique patterns during embryogenesis. ppGaNTase-T1, -T2, -T4, and -T9 were expressed more ubiquitously than ppGaNTase-T3, -T5, and -T7, Organ systems with discrete accumulation patterns of ppGaNTase family members include th e gastrointestinal tract (intestine, liver, stomach, submandibular gland), nervous system (brain, eye), lung, bone, yolk sac, and developing craniofac ial region. The pattern in the craniofacial region included differential ex pression by family members in developing mandible, teeth, tongue and discre te regions of the brain including the pens and migratory, differentiating n eurons. Additionally, ppGaNTase-T5 accumulates in a subset of mesenchymal c ells at the ventral-most portions of the E12.5 maxilla and mandible underly ing the dental lamina, The unique spatiotemporal expression of the differen t ppGaNTase family members during development suggests unique roles for eac h of these gene products.