Fig. 6.

Distribution of ISG expression in ADAR1^K999N mouse brain by RNA in situ hybridization (ISH). ISG expression on formalin-fixed paraffin-embedded (FFPE) sections of ADAR1^K999N mice were detected by ISH for ISG15 and CXCL10 counterstaining with hematoxylin. A ISH for ISG15. (A) Low power coronal section shows multiple foci of hybridization (red). Bar = 1 mm. (B) Medium power allows resolution of staining in the choroid plexus and ependyma surrounding ventricle (V). Bar = 200 μm. (C) High power of the thalamus showing hybridization within a discrete focus of neurons. Bar = 100 μm. (D) High power of the cerebellum shows hybridization in Purkinje neurons (arrowheads) and pia matter (arrows). Bar = 100 μm. (E) High power of cortical gray matter shows hybridization in a subpopulation of neurons. Bar = 100 μm. (F) The highest power of cortical gray matter shows hybridization in neuronal cytoplasm. Bar = 50 μm. B ISH for CXCL10 (red). (A) Low power coronal section shows multiple foci of hybridization (red). Bar = 1 mm. (B) Medium power allows resolution of staining in the choroid plexus (CP) and ependyma surrounding ventricle (V) and focus on the thalamus (between arrows). Bar = 200 μm. (C) High power of the thalamus shows a circular focus of hybridization consisting of cells with blunted processes amidst normal appearing neurons. Bar = 100 μm. (D) High power of the ventricle shows hybridization in ependyma and choroid plexus cells. Bar = 100 μm. (E) High power of cortical gray matter (GM) and white matter (WM) shows hybridization in microglia with blunted processes in both regions. Bar = 100 μm. (F) High power of cortical gray matter shows a solitary focus of hybridization in microglia with blunted processes. Bar = 100 μm