Penetrance of eye defects in mice heterozygous for mutation of Gli3 is enhanced by heterozygous mutation of Pax6

BACKGROUND: Knowledge of the consequences of heterozygous mutations of developmentally important genes is important for understanding human genetic disorders. The Gli3 gene encodes a zinc finger transcription factor and homozygous loss-of-function mutations of Gli3 are lethal. Humans heterozygous for mutations in this gene suffer Greig cephalopolysyndactyly or Pallister-Hall syndromes, in which limb defects are prominent, and mice heterozygous for similar mutations have extra digits. Here we examined whether eye development, which is abnormal in mice lacking functional Gli3, is defective in Gli3(+/- )mice. RESULTS: We showed that Gli3 is expressed in the developing eye but that Gli3(+/- )mice have only very subtle eye defects. We then generated mice compound heterozygous for mutations in both Gli3 and Pax6, which encodes another developmentally important transcription factor known to be crucial for eye development. Pax6(+/-); Gli3(+/- )eyes were compared to the eyes of wild-type, Pax6(+/- )or Gli3(+/- )siblings. They exhibited a range of abnormalities of the retina, iris, lens and cornea that was more extensive than in single Gli3(+/- )or Pax6(+/- )mutants or than would be predicted by addition of their phenotypes. CONCLUSION: These findings indicate that heterozygous mutations of Gli3 can impact on eye development. The importance of a normal Gli3 gene dosage becomes greater in the absence of a normal Pax6 gene dosage, suggesting that the two genes co-operate during eye morphogenesis

行政用文字の調査研究 : 汎用電子情報交換環境整備プログラム

国立国語研究所国立国語研究所国立国語研究所The National Institute for Japanese LanguageThe National Institute for Japanese LanguageThe National Institute for Japanese Languageさまざまな行政手続をインターネットで行う「電子政府」を構築するためには,氏名,住所,法人名などの固有名に使われる文字をも含め,行政情報処理で必要とされる文字をコンピュータで扱えるような環境を整えなければならない。国立国語研究所・情報処理学会・日本規格協会では,行政情報処理で必要とされる文字の調査研究(汎用電子情報交換環境整備プログラム)を実施している。この調査研究において,住民基本台帳ネットワーク統一文字,戸籍統一文字,登記統一文字を検討し,行政用文字の文字コード規格(JIS X O213,ISO/IEC10646)によるカバー率を明らかにした。また,漢和辞典に掲載されていない文字について,地名資料による文字同定を進めている

Loss of β-III Spectrin Leads to Purkinje Cell Dysfunction Recapitulating the Behavior and Neuropathology of Spinocerebellar Ataxia Type 5 in Humans

Mutations in SPTBN2, the gene encoding β-III spectrin, cause spinocerebellar ataxia type 5 in humans (SCA5), a neurodegenerative disorder resulting in loss of motor coordination. How these mutations give rise to progressive ataxia and what the precise role β-III spectrin plays in normal cerebellar physiology are unknown. We developed a mouse lacking full length β-III spectrin and found that homozygous mice reproduced features of SCA5 including gait abnormalities, tremor, deteriorating motor coordination, Purkinje cell loss and cerebellar atrophy (molecular layer thinning). In vivo analysis reveals an age-related reduction in simple spike firing rate in surviving β-III(−/−) Purkinje cells while in vitro studies show these neurons to have reduced spontaneous firing, smaller sodium currents and dysregulation of glutamatergic neurotransmission. Our data suggest an early loss of EAAT4- (protein interactor of β-III spectrin) and subsequent loss of GLAST-mediated uptake may play a role in neuronal pathology. These findings implicate a loss of β-III spectrin function in SCA5 pathogenesis and indicate there are at least two physiological effects of β-III spectrin loss that underpin a progressive loss of inhibitory cerebellar output, namely an intrinsic Purkinje cell membrane defect due to reduced sodium currents and alterations in glutamate signaling