title: Mice with disrupted GM2/GD2 synthase gene lack complex gangliosides but exhibit only subtle defects in their nervous system.
abstract: Gangliosides, sialic acid-containing glycosphingolipids, are abundant in the vertebrate (mammalian) nervous system. Their composition is spatially and developmentally regulated, and gangliosides have been widely believed to lay essential roles in establishment of the nervous system, especially in neuritogenesis and synaptogenesis. However, this has never been tested directly. Here we report the generation of mice with a disrupted beta 1,4-N-acetylgalactosaminyltransferase (GM2/GD2 synthase; EC 2.4.1.92) gene. The mice lacked all complex gangliosides. Nevertheless, they did not show any major histological defects in their nervous systems or in gross behavior. Just a slight reduction in the neural conduction velocity from the tibial nerve to the somatosensory cortex, but not to the lumbar spine, was detected. These findings suggest that complex gangliosides are required in neuronal functions but not in the morphogenesis and organogenesis of the brain. The higher levels of GM3 and GD3 expressed in the brains of these mutant mice may be able to compensate for the lack of complex gangliosides.
authors.affiliation: Department of Oncology, Nagasaki University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takamiya
authors.forename: A
authors.initials: A
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Furukawa
authors.forename: S
authors.initials: S
authors.lastname: Yamashiro
authors.forename: M
authors.initials: M
authors.lastname: Shin
authors.forename: M
authors.initials: M
authors.lastname: Okada
authors.forename: S
authors.initials: S
authors.lastname: Fukumoto
authors.forename: M
authors.initials: M
authors.lastname: Haraguchi
authors.forename: N
authors.initials: N
authors.lastname: Takeda
authors.forename: K
authors.initials: K
authors.lastname: Fujimura
authors.forename: M
authors.initials: M
authors.lastname: Sakae
authors.forename: M
authors.initials: M
authors.lastname: Kishikawa
authors.forename: H
authors.initials: H
authors.lastname: Shiku
authors.forename: K
authors.initials: K
authors.lastname: Furukawa
authors.forename: S
authors.initials: S
authors.lastname: Aizawa
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000033:anatomy & histology; D005073:Evoked Potentials, Somatosensory; D005678:G(M2) Ganglioside / Q000502:physiology*; D005732:Gangliosides / Q000502:physiology*; D005796:Genes; D051379:Mice; D018345:Mice, Knockout; D017350:N-Acetylgalactosaminyltransferases / Q000502:physiology*; D009424:Nervous System Physiological Phenomena; D009431:Neural Conduction; D013003:Somatosensory Cortex / Q000502:physiology; D000097763:Polypeptide N-acetylgalactosaminyltransferase
chemical_list: D005678:G(M2) Ganglioside; D005732:Gangliosides; D017350:N-Acetylgalactosaminyltransferases; D000097763:Polypeptide N-acetylgalactosaminyltransferase; C019403:ganglioside, GD2; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase