mHtt gene-dose impacts on DARPP32 protein levels.

<p>DARPP32 immunostaining in sagittal mouse brain sections of 8-month-old wildtype (A), HdhQ150 HET (B), and HdhQ150 HOM mice (C). Staining was performed by automated paraffin immunohistochemistry using the Ventana Discovery XT technology and DAB as chromogen. Overall DARPP32 staining intensities clearly decline from wildtype (A) to HdhQ150 HET (B) and HOM mice (C), and in all DARPP32⁺ brain regions including striatum (Str), cortex (Ctx), thalamus (Tha), and cerebellum (Cer). The images are representative of results obtained from 2 WT, 6 HdhQ150 HET and 6 HdhQ150 HOM mice. (D) Representative western blot of DARPP32 protein levels in 6-month-old wildtype (WT), HdhQ150 HET and HOM mice, 3 of each. (E) Quantification of Western blot signals (normalized to wildtype and loading control β-actin) revealed a highly significant reduction of DARPP32 levels in HdhQ150 striatum, as compared to wildtype striatum (n = 6, p<0.005). The difference between HdhQ150 HET (n = 9) and HdhQ150 HOM (n = 6) DARPP32 levels was also statistically significant (p<0.01). Quantification results are the average of three independent Western blots. A second control (tubulin) shows that DARPP32 changes are not due to differences in loading. Statistics: One-way ANOVA, Holm-Sidak's multiple comparisons test