Figure 10.

Overexpressed contactin redirects laminar targeting of neurites. a, b, Small groups of retinal cells were transduced at E2 with constructs that encoded Venus alone (a) or Venus plus Cntn2. Retinas were analyzed at E17. Left panels show examples, and results are quantified in right panels. Venus-expressing processes were present in all IPL sublaminae at equal frequency, whereas ectopic expression of Cntn2 biased neurites to S2 and S4. c, Section from Cntn2-transfected retina stained with anti-ChAT and anti-GFP. The localization of the Venus-positive arbors, directly beneath the ChAT-positive arbors, precisely matches that of endogenous Cntn2 (see Fig. 5d). d, e, Overexpression of Cntns1 and 3 bias neurites to S1 and S5 or S3, respectively. These patterns are similar to those of endogenous Cntns1 and 3 in the IPL (see Fig. 5a,c). Concentration of processes in S1/S5, S2/S4, and S3 was significant for cntn1, cntn2, and cntn3, respectively (p < 0.01 by χ² test) but not for control. Scale bar: 10 μm for a; 5 μm for c.