Figure 1. Rer1 is highly expressed in Purkinje cells (PCs) and specifically deleted in Rer1^ΔPC mice.

(a) Left: radioactive in-situ hybridization (ISH) of a wt cerebellar section with a Rer1-specific antisense probe; middle: X-Gal staining of a cerebellar slice of a heterozygous Rer1-genetrap mouse with a β-Geo insertion in intron 3 of Rer1¹³. Arrows indicate PC layer; right: immunostaining of a cerebellar slice with Rer1 antibody (red) and calbindin (calb, green). Asterisks indicate PCs. Scalebar 150 μm (left, middle) and 10 μm (right). (b) Targeting strategy for conditional deletion of Rer1. Shown is the genomic structure (top), the position of the loxP sites in the Rer^fl/fl allele and the deleted Rer1^ΔPC allele after crossing with the PC-specific L7Pcp2-Cre line. (c) Rer1 is specifically deleted in PCs. Vibratome sections of perfused 4 months old animals with the indicated genotype were processed for immunofluorescence with antibodies against Rer1 and calbindin (Calb) and imaged by confocal microscopy. Three consecutive confocal sections were merged. In the lower panel a magnification of the Rer1 staining of the boxed area is shown. PCs are outlined. Scalebar 10 μm. (d) Deletion of Rer1 in PCs starts before P13 and is completed at P16. Sagittal sections from cerebella from perfused Rer1^ΔPC of indicated age were stained for Rer1 and images were taken from the anterior lobe at the position indicated in the overview Hoechst-stained image on the right. Scale bar 50 μm for Rer1 staining, 150 μm for Hoechst.