Figure 1.

Reporter gene expression in the Cx30.2^lacZ/lacZ retina is confined to the ganglion cell layer (GCL) and the proximal inner nuclear layer (INL). (A) Successful deletion of Cx30.2 was confirmed by RT-PCR. The Cx30.2-specific transcript was only detected in Cx30.2^+/+ and not in Cx30.2^lacZ/lacZ mice. Intron-spanning actin primers were used to prove that samples were not contaminated by genomic DNA: only the 573 bp for cDNA is visible whereas the 1027 bp for genomic DNA was not detected. (B) Immunofluorescence staining for β-galactosidase (β-gal) in a vertical section of the Cx30.2^lacZ/lacZ retina. The inset on the left is a transmission image of the same area indicating the layers of the retina (ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer). In the INL, immunoreactive cells are visible right at the border between INL and IPL (arrows) or a bit more distal (arrowhead). (C) X-gal staining of a Cx30.2^lacZ/lacZ retina. Blue signals indicate β-gal expression. (D) Same image as in (C) showing the extracted signals of the X-gal staining along a Z-series and confirming the exclusive expression in the GCL and the proximal INL. (E,F) Whole-mount stainings for β-gal (E₁,F₁) and choline acetyltransferase (ChAT, E₂,F₂) in the INL (E) and GCL (F) to quantify β-gal expression. ChAT signals never colocalized with β-gal signals. (G) Schematic of a whole-mount retina indicating the approximate locations for quantification. (H) Quantification of β-gal expressing cells depending on the eccentricity within the retina (mean ± SD, n = 8 central-to-peripheral axes). Scale bars: (B,E,F) 50 μm; (C,D) 20 μm; (G) 1 mm.