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A reeler is a mouse mutant, so named because of its characteristic "reeling" gait. This is caused by profound hypoplasia of the mouse's cerebellum, in which the normal cerebellar folia are missing. The mutation is autosomal and recessive. Cortical neurons are generated normally but are abnormally placed, resulting in disorganization of cortical laminar layers in the CNS. The reason is the lack of Reelin, an extracellular matrix glycoprotein, which during the corticogenesis is secreted mainly by the Cajal-Retzius cells. In the reeler neocortex, cortical plate neurons are aligned in a practically inverted fashion (‘‘outside-in’’). In the ventricular zone of the cortex fewer neurons have been found to have radial glial processes.〔Hartfuss E, Forster E, Bock HH, Hack MA, Leprince P, Luque JM, Herz J, Frotscher M, Gotz M. (2003) ''Reelin signaling directly affects radial glia morphology and biochemical maturation.'' Development. 130(19):4597-609. PMID 12925587〕 In the dentate gyrus of hippocampus, no characteristic radial glial scaffold is formed and no compact granule cell layer is established.〔Weiss, K.H., Johanssen, C., Tielsch, A., Herz, J., Deller, T., Frotscher, M. & Förster, E. (2003) ''Malformation of the radial glial scaffold in the dentate gyrus of reeler mice, scrambler mice, and ApoER2/VLDLR-deficient mice.'' J. Comp. Neurol., 460, 56–65. PMID 12687696〕 Therefore, the reeler mouse presents a good model in which to investigate the mechanisms of establishment of the precise neuronal network during development. ==Types of reelers== There are two types of the reeler mutation: * Albany2 mutation (Reln(rl-Alb2)〔Royaux I, Bernier B, Montgomery JC, Flaherty L, Goffinet AM. (1997) ''Reln(rl-Alb2), an allele of reeler isolated from a chlorambucil screen, is due to an IAP insertion with exon skipping.'' Genomics. 42(3):479-82. PMID 9205121〕 * Orleans mutation (Reln-rl-orl, or rl-orl),〔Lalonde R, Hayzoun K, Derer M, Mariani J, Strazielle C. (2004) ''Neurobehavioral evaluation of Reln-rl-orl mutant mice and correlations with cytochrome oxidase activity.'' Neurosci Res. 49(3):297-305. PMID 15196778〕 in which reelin lacks a C-terminal region and a part of the eighth reelin repeat. This hampers the secretion of the protein from the cell. In order to unravel the reelin signaling chain, attempts are made to cut the signal downstream of reelin, leaving reelin expression intact but creating the reeler phenotype, sometimes a partial phenotype, thus confirming the role of downstream molecules. The examples include: * Double knockout of VLDLR and ApoER2 receptors; * Double knockout of Src and Fyn kinases. *Cre-loxP recombination mice model that lacks Crk and CrkL in most neurons. Was used to show that Crk/CrkL lie downstream of DAB1] in the reelin signaling pathway. * Scrambler mouse 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「reeler」の詳細全文を読む スポンサード リンク
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