Figure 5.

Ipsilateral RGCs Do Not Express Unc5c

(A–A’’) ISH for Unc5c (red) in an E16.5 retinal section shown as a single channel (A’) or in combination with immunohistochemistry for Zic2 (green, A and A’’). Red arrowheads indicate peripheral limit of Unc5c expression, green arrowheads central limit of Zic2 expression, and white arrowhead the region where the neural retina meets the ciliary margin zone (CMZ).

(B) ISH for Unc5c (red) combined with immunohistochemistry for Zic2 in Zic2 mutant embryos. Red arrowhead marks the most peripheral limit of Unc5c mRNA expression and white arrowhead the region where the neural retina meets the CMZ.

(C and D) ISH for Unc5c (red) in retinal sections electroporated with EGFP-encoding (C) or Zic2/EGFP-encoding (D) plasmids. Unc5c mRNA expression is reduced after ectopic expression of Zic2.

(E and F) Optic chiasms from E16.5 embryos electroporated with plasmids encoding Zic2/EGFP (F) or EGFP alone (E). Red arrowhead indicates the ectopic ipsilateral projection in embryos electroporated with Zic2 and empty arrowhead the reduced number of EGFP-labeled axons in the contralateral optic nerve of Zic2 electroporated embryos compared to the control.

(G) Mean (± SEM) normalized fluorescence intensity in the contralateral optic nerve and the ipsilateral optic tract of E16.5 embryos electroporated with plasmids encoding Zic2/EGFP or EGFP alone.

Error bars indicate ± SEM. (^∗∗p < 0.01, ^∗∗∗p < 0.001, Student’s unpaired t test).