Poster Sessions

DEV-8

E. Tian

E. Tian, M.P. Hoffman, K.G. Ten Hagen

Investigating the Role of Mucin-Type O-linked Glycosylation during Murine Submandibular Gland Development

Glycosylation is one of the most fundamental and abundant post-translational protein modifications found in nature, having roles in protein stability and processing, conserved signaling events during development, and certain genetic diseases. Previous work from our laboratory demonstrated that initiation of mucin-type O-linked glycosylation by the UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase enzyme family (pGalNAcTs in mammals or PGANTs in Drosophila) is essential for viability during Drosophila development. Here we describe the role of mucin-type O-linked glycosylation in mouse embryonic submandibular gland (SMG) development. Microarray analysis of staged SMGs (E12-adult) demonstrated unique temporal expression patterns for 17 pGalNAcTs during mouse SMG development. To examine the biological role of the pGalNAcTs, we analyzed SMGs from mice deficient for pGalNAcT-1 (T1), an isoform that is expressed early during SMG development. SMGs from embryonic stage (E12) T1 knockout animals had a smaller initial end bud and reduced growth rate compared with wild type SMGs. However, the growth rate was similar to wild type by later embryonic stages (E13-E14), indicating a stage-specific, developmental delay in T1 knockout animals. Our work highlights the coordinated expression of members of the pGalNAcT family during SMG development and illustrates the importance of mucin-type O-linked glycosylation during murine branching morphogenesis.