Figure 1. Cdh6, Cdh9 and Cdh10 pattern D/V-ooDSGC dendrites.
(A) Retinal ON-OFF direction-selective circuit, showing expression of Cdh6, Cdh8, Cdh9 and Cdh10 in bipolar cells (BCs), starburst amacrine cells (SACs) and dorsally and ventrally preferring ON-OFF direction selective retinal ganglion cells (D/V-ooDSGCs).
(B) The cdh6-cdh9-cdh10 locus on mouse Chromosome 15 and mutant alleles used in C-H. CreER, tamoxifen-inducible cre-recombinase; LacZ, beta-galactosidase; dotted line, indel deletion.
(C) ooDSGCs in control, Cdh6, Cdh10, Cdh6-10, Cdh6-9-10 mutants and Cdh6-9-10 heterozygotes at postnatal day (P) 21. ooDSGCs were labeled using a Cre-dependent reporter (YFP, green); sections were co-stained for vesicular acetylcholine transporter (vAChT, red) to label SAC dendrites and neurotrace (NT, blue) to visualize somata. Scale bar, 20 μm.
(D) Mean YFP intensity (± SEM) of ooDSGC dendrites across the inner plexiform layer (IPL) from indicated genotypes, derived from images such as those in C (n≥10 cells from each of ≥5 mice of each genotype; light lines show data from individual mice and heavy lines show means). A similarity index (see Methods), was used to tested differences in lamination pattern across genotypes. Cdh6-9-10 mutants differed from the other 5 genotypes (p<0.01), which did not differ significantly from each other.
(E) ooDSGCs in Cdh6-9-10 mutant retinas labeled using a Brainbow virus that marks individual cells in distinct colors. Separate channels are shown for the boxed region. Sections were also co-stained with anti-vAChT to label SAC dendrites (right panel).
(F) Mean vAChT level (± SEM) of SAC dendrites across the IPL in control and Cdh6-9-10 mutant retinas, measured as in “D” from images such as those in C (n as in Fig. 1D) for SACs only. SACs in control and Cdh6-9-10 mutants do not differ significantly in lamination, assessed as in D.
(G) D/V-ooDSGCs in control and Cdh6-9-10 mutant retinas at P7 labeled as in C Scale bar, 20 μm.
(H) Mean YFP intensity (± SEM) of P7 D/V-ooDSGC dendrites across the inner plexiform layer (IPL) from control and Cdh6-9-10 mutant retinas, measured from images such as those in E (n as in Fig. 1D). Similarity score indicates that lamination in mutants differs significantly from controls (p<0.05).