Figure 1.

Cx36-GCaMP transgenic mouse. A, Cx36-GCaMP consists of mouse Cx36 with GCaMP3 fused to the C terminal. Regulatory phosphorylation sites of Cx36 are shown. Cx36-GCaMP expressed in cultured cells has been shown to display normal functional regulation by protein kinases (Moore et al., 2020). B, The Cx36-GCaMP transgene consists of 4.1 kb of genomic sequence upstream of mouse Cx36 exon 1, exon 1, intron 1, and exon 2 and SV40 polyadenylation signal derived from the Cx36-GCaMP expression plasmid. The endogenous transcription initiation site is indicated by the right arrow, and transcript splicing is indicated by the chevron between exons 1 and 2. C, D, Cx36-GCaMP expression in retina of transgenic mice. Cx36-GCaMP labeled with an anti-GFP antibody is green; Cx36 immunolabeling is magenta. Cx36-GCaMP is expressed in punctate spots in both IPL and OPL, where Cx36 is normally expressed. INL, Inner nuclear layer. Scale bars: 20 μm. E, Cx36-GCaMP expression in olfactory bulb glomeruli labeled with anti-GFP antibody. Scale bar: 20 μm. F–H, Expression of Cx36-GCaMP in the pancreas. Cx36-GCaMP (green) is found between islet cells in the pancreas that contain insulin (F, magenta). Labeling with an anti-Cx36 antibody (G, cyan) is nearly identical to labeling of Cx36-GCaMP with an anti-GFP antibody (H, green). Scale bars: 10 μm.