Figure 1-figure supplement 1-source data 1.

(A–G) Confocal images of Mauthner circuit neurons and stereotypical electrical synaptic contacts in 5-day-post-fertilization, zf206Et zebrafish larvae from tjp1a/ZO1a^-/- mutant (A,B) and tjp1a/ZO1a^-/-; tjp1b/ZO1b^-/- double mutant animals (C,D). Animals are stained with anti-GFP (green), anti-zebrafish-Cx35.5 (cyan), anti-zebrafish-Cx34.1 (yellow), and anti-human-ZO1 (magenta). In panels (E–G) animals are stained individually with the indicated antibody. Scale bar = 2 µm in all images. (A,C) Images of the stereotypical location of CE contact sites on the Mauthner lateral dendrite. Images are maximum-intensity projections of ~5 µm and neighboring panels show individual channels. (B,D) Images of the sites of contact of Mauthner/CoLo processes in the spinal cord. Images are individual Z-sections and neighboring panels show individual channels. (E–G) Images of the Mauthner CEs stained for individual electrical synapse components. Images are maximum-intensity projections of E ~ 3.80 µm, F ~ 3.04 µm, G ~ 6.08 µm. (H) Zebrafish brain extracts from animals with indicated genotypes were immunoprecipitated and immunoblotted with anti-Cx34.1 antibody (top) or anti-Cx35.5 antibody (bottom). Results are representative of three independent experiments. (I) Quantification of CE counts based on individual stains in high-contrast images of the indicated genotypes. In this graph, wt data for all individual antibodies has been combined from all experiments depicted; individual data for each experiment can be found in the associated data table. The height of the bar represents the mean of the sampled data normalized to the wt average, and circles represent the normalized value of each individual animal (wt ALL ABs, n = 47; tjp1b Cx35/36 AB, n = 21; tjp1b Cx34.1 AB, n = 26; tjp1b ZO1 AB, n = 15; tjp1a Cx35/36 AB, n = 9; tjp1a Cx34.1 AB, n = 8; tjp1a ZO1 AB, n = 6; gjd2a Cx35/36 AB, n = 29; gjd2a Cx34.1 AB, n = 17; gjd2a ZO1 AB, n = 15; gjd2a Cx35.5 AB, n = 18; gjd1a Cx35/36 AB, n = 16; gjd1a Cx34.1 AB, n = 12; gjd1a ZO1 AB, n = 14; gjd2b Cx35/36 AB, n = 18; gjd2b Cx34.1 AB, n = 19; gjd2b ZO1 AB, n = 17; gjd1b Cx35/36 AB, n = 29; gjd1b Cx34.1 AB, n = 18; gjd1b ZO1 AB, n = 31). Error bars are ± SEM. Asterisks (*) indicate significant differences between wt and mutant counts (****=p<0.0001, **=p<0.01). Associated experimental statistics can be found in Figure 1—figure supplement 1—source data 1