title: Expression of cyclin E in postmitotic neurons during development and in the adult mouse brain.
abstract: Cyclin E, a member of the G1 cyclins, is essential for the G1/S transition of the cell cycle in cultured cells, but its roles in vivo are not fully defined. The present study characterized the spatiotemporal expression profile of cyclin E in two representative brain regions in the mouse, the cerebral and cerebellar cortices. Western blotting showed that the levels of cyclin E increased towards adulthood. In situ hybridization and immunohistochemistry showed the distributions of cyclin E mRNA and protein were comparable in the cerebral cortex and the cerebellum. Immunohistochemistry for the proliferating cell marker, proliferating cell nuclear antigen (PCNA) revealed that cyclin E was expressed by both proliferating and non-proliferating cells in the cerebral cortex at embryonic day 12.5 (E12.5) and in the cerebellum at postnatal day 1 (P1). Subcellular localization in neurons was examined using immunofluorescence and western blotting. Cyclin E expression was nuclear in proliferating neuronal precursor cells but cytoplasmic in postmitotic neurons during embryonic development. Nuclear cyclin E expression in neurons remained faint in newborns, increased during postnatal development and was markedly decreased in adults. In various adult brain regions, cyclin E staining was more intense in the cytoplasm than in the nucleus in most neurons. These data suggest a role for cyclin E in the development and function of the mammalian central nervous system and that its subcellular localization in neurons is important. Our report presents the first detailed analysis of cyclin E expression in postmitotic neurons during development and in the adult mouse brain.
authors.affiliation: Department of Histology and Cell Biology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan. yayoi@yokohama-cu.ac.jp
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Yuko
authors.initials: Y
authors.lastname: Matsunaga
authors.forename: Masahito
authors.initials: M
authors.lastname: Takiguchi
authors.forename: Masa-Aki
authors.initials: MA
authors.lastname: Ikeda
mesh_terms: D000818:Animals; D002453:Cell Cycle; D049109:Cell Proliferation; D002531:Cerebellum / Q000737:chemistry / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D054022:Cerebrum / Q000737:chemistry / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D019927:Cyclin E / Q000032:analysis* / Q000235:genetics*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D011689:Purkinje Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D019927:Cyclin E