title: Mice expressing only monosialoganglioside GM3 exhibit lethal audiogenic seizures.
abstract: Gangliosides are a family of glycosphingolipids that contain sialic acid. Although they are abundant on neuronal cell membranes, their precise functions and importance in the central nervous system (CNS) remain largely undefined. We have disrupted the gene encoding GD3 synthase (GD3S), a sialyltransferase expressed in the CNS that is responsible for the synthesis of b-series gangliosides. GD3S-/- mice, even with an absence of b-series gangliosides, appear to undergo normal development and have a normal life span. To further restrict the expression of gangliosides, the GD3S mutant mice were crossbred with mice carrying a disrupted GalNAcT gene encoding beta1,4-N-acetylgalactosaminyltransferase. These double mutant mice expressed GM3 as their major ganglioside. In contrast to the single mutant mice, the double mutants displayed a sudden death phenotype and were extremely susceptible to induction of lethal seizures by sound stimulus. These results demonstrate unequivocally that gangliosides play an essential role in the proper functioning of the CNS.
authors.affiliation: Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: H
authors.initials: H
authors.lastname: Kawai
authors.forename: M L
authors.initials: ML
authors.lastname: Allende
authors.forename: R
authors.initials: R
authors.lastname: Wada
authors.forename: M
authors.initials: M
authors.lastname: Kono
authors.forename: K
authors.initials: K
authors.lastname: Sango
authors.forename: C
authors.initials: C
authors.lastname: Deng
authors.forename: T
authors.initials: T
authors.lastname: Miyakawa
authors.forename: J N
authors.initials: JN
authors.lastname: Crawley
authors.forename: N
authors.initials: N
authors.lastname: Werth
authors.forename: U
authors.initials: U
authors.lastname: Bierfreund
authors.forename: K
authors.initials: K
authors.lastname: Sandhoff
authors.forename: R L
authors.initials: RL
authors.lastname: Proia
mesh_terms: D000367:Age Factors; D000818:Animals; D002490:Central Nervous System / Q000502:physiology; D003433:Crosses, Genetic; D005679:G(M3) Ganglioside / Q000096:biosynthesis*; D005732:Gangliosides / Q000502:physiology; D015723:Gene Library; D016695:Glycosyltransferases / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008954:Models, Biological; D008957:Models, Genetic; D009154:Mutation; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics; D010641:Phenotype; D012640:Seizures / Q000235:genetics* / Q000378:metabolism*; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism
chemical_list: D005679:G(M3) Ganglioside; D005732:Gangliosides; D016695:Glycosyltransferases; D017350:N-Acetylgalactosaminyltransferases; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase; D012799:Sialyltransferases; C043662:alpha-N-acetylneuraminate alpha-2,8-sialyltransferase