The goal of this research is to clarify the nature of ganglioside abnormalities in mutant mouse embryos. Gangliosides are a family of sialic acid-containing glycosphingolipids that are enriched in the central nervous system (CNS) and are thought to play an important role in neuronal differentiation. The tW1 mouse mutation is located within the T/t complex on chromosome 17 and causes embryonic lethality from failed neuronal differentiation within the neural tube. Recent findings indicate the tW1/tW1 embryos express reductions of gangliosides in the """"""""b"""""""" metabolic pathway (GD3, GD1b, GT1b, and GQ1b) and elevations of ganglioside in the """"""""a"""""""" metabolic pathway (GM3, GM2, GM1, and GD1a). This shift in ganglioside distribution strongly suggests that the mutants have a partial deficiency in the sialyltransferase activity that catalyzes the synthesis of GD3 from GM3: a key enzyme in the synthesis of the complex gangliosides. Moreover, gangliosides of the """"""""b"""""""" pathway have been implicated in neuronal differentiation and neuritogenesis. This hypothesis will be tested through a developmental analysis of ganglioside composition and metabolism in normal and tW1/tW1 mutants. The gangliosides will be studied from embryonic day 13 (E-13) to E-17 in whole embryos and in embryonic CNS tissues. The composition of neutral glycolipids will also be examined. Total ganglioside content will be analyzed using gas-liquid chromatography and the individual ganglioside species will be analyzed using high performance thin-layer chromatography and densitometry. A specific objective will be to determine if the ganglioside abnormalities are a primary or secondary effect of the tW1 mutation. This will be approached through in vivo and in vitro studies of ganglioside biosynthesis in the +/+ and tW1/tW1 embryos and in the phenotypically normal +/tW1 heterozygotes. The sialyltransferase activities that catalyze the synthesis of GM3, GD3, GD1a, and GQ1b will be analyzed in enzyme enriched membrane preparations from the +/+, +/tW1, and tW1/tW1 embryos. The N- acetylgalactosaminyltransferase activity that catalyzes the synthesis of GM2 from GM3 (a key enzyme in the synthesis of """"""""a"""""""" pathway gangliosides) will also be analyzed in the normal and mutant embryos. The activity of GM1 beta-galactosidase will also be studied using GM1 as a natural substrate in embryos of inbred DBA/2 and C57BL/6 mice and their F1 hybrids. Because DBA mice have elevated levels of GM1 at both embryonic and juvenile ages, they may express a mild form of GM1 gangliosidosis and serve as an important animal model for this disorder. Since this is the first study of ganglioside abnormalities associated with inherited embryonic lethality and failed CNS development in mammals, new insight can be obtained on ganglioside function and on the genetic regulation of ganglioside metabolism.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Research Project (R01)
Project #
Application #
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Boston College
Schools of Arts and Sciences
Chestnut Hill
United States
Zip Code
Brigande, J V; Platt, F M; Seyfried, T N (1998) Inhibition of glycosphingolipid biosynthesis does not impair growth or morphogenesis of the postimplantation mouse embryo. J Neurochem 70:871-82
Ecsedy, J A; Manfredi, M G; Yohe, H C et al. (1997) Ganglioside biosynthetic gene expression in experimental mouse brain tumors. Cancer Res 57:1580-3
Cotterchio, M; Seyfried, T N (1994) Serum gangliosides in mice with metastatic and non-metastatic brain tumors. J Lipid Res 35:10-4
Seyfried, T N; Novikov, A M; Irvine, R A et al. (1994) Ganglioside biosynthesis in mouse embryos: sialyltransferase IV and the asialo pathway. J Lipid Res 35:993-1001
el-Abbadi, M; Seyfried, T N (1994) Influence of growth environment on the ganglioside composition of an experimental mouse brain tumor. Mol Chem Neuropathol 21:273-85
Cotterchio, M; Seyfried, T N (1993) The influence of ImuVert, a biological response modifier, on the growth and ganglioside composition of murine neural tumors. Mol Chem Neuropathol 20:163-72
Seyfried, T N; Ariga, T (1992) Neutral glycolipid abnormalities in a t-complex mutant mouse embryo. Biochem Genet 30:557-65
Seyfried, T N; el-Abbadi, M; Roy, M L (1992) Ganglioside distribution in murine neural tumors. Mol Chem Neuropathol 17:147-67
Novikov, A M; Seyfried, T N (1991) Ganglioside GD3 biosynthesis in normal and mutant mouse embryos. Biochem Genet 29:627-38
Neumann, P E; Seyfried, T N (1990) Mapping of two genes that influence susceptibility to audiogenic seizures in crosses of C57BL/6J and DBA/2J mice. Behav Genet 20:307-23

Showing the most recent 10 out of 12 publications