Fig. 4.

Impaired dendritic localization of IP₃RI mRNA in Hzf-mutant mice. (A) In situ hybridization analysis of IP₃RI transcripts in the cerebella of Hzf-mutant mice. Dendritic localization within the Purkinje cells was reduced in the Hzf-mutant mice. ML, molecular layer; PCL, Purkinje cell layer. (B) Scan analysis of representative in situ hybridization signal for IP₃RI mRNAs in wild-type and mutant Purkinje cells. PCL, Purkinje cell layer; ML, molecular layer. (C) Quantitation of IP₃RI mRNAs in the Purkinje cell layer (PCL, Top) and molecular layer (ML, Middle) of wild-type and Hzf-mutant mice (n = 3 mice per genotype, each >20 cells per slice). Furthermore, the mRNA level in the molecular layer was normalized to that in the Purkinje cell layer positioned just below the molecular layer (Bottom). Values are the mean ± SEM. **, P < 0.01. (D) Dendritic localization of transfected 3′ UTR of IP₃RI mRNA was reduced in cultured hippocampal neurons from Hzf-mutant mice (n = 4, total 247-675 neurons per construct); the reduced dendritic mRNA localizations were rescued by cotransfection with a CMV-Hzf construct (n = 3, total 103-466 neurons per construct). Values are the mean ± SEM. *, P < 0.05. Statistical significance was assessed by using a Student t test in C and D. (Scale bars: 25 μm in A and B.)