Fig. 3.

Cdh3 overexpression can drive fasciculation between nonhomotypic cells. Retinas of Vgat-Cre mice were electroporated in vivo at P0 with the Cre-inducible expression construct pCALNL-DsRed, alone or along with pCALNL-Cdh3. After 2 wk, these were fixed, stained for DsRed, and imaged en face. (A and B) Mice wild-type for Dscam (A) and Dscam^cKO/cKO mutants with conditional mutation in GABAergic amacrine cells (B) were electroporated with DsRed alone (Upper). There was no appreciable fasciculation (depicted in Lower) between electroporated cells. (C) Likewise, when retinas wild-type for Dscam were coelectroporated with DsRed and Cdh3 (Upper), no fasciculation (depicted in Lower) was observed. (D) In contrast, when DsRed and Cdh3 were together introduced into Dscam^cKO/cKO mutant retinas (Upper), significant fasciculation (depicted in Lower) was observed (arrowheads). (E) Images were compared for fasciculation using the Elo score. P = 0.025 by pairwise Wilcoxon rank sum test compared with each other condition. n = 6 mice per condition. (Scale bar: 100 μm.)