Figure 5. Increased disruption of corneal innervation in Npn1^Sema−/−;Npn2^−/− double mutants.

Whole mount and sections of E12.5–E13.5 eyes were immunostained with TuJ1. Sections were counter stained with DAPI. (A–B) Several nerve bundles projected into ectopic regions of the anterior eye (asterisks), the dorsal temporal region (arrow) and presumptive stroma (arrowhead) are prematurely innervated. (C) Quantification of axon lengths at E12.5 showed that more nerve bundles innervated the Npn1^Sema−/−;Npn2^−/− double mutant cornea than Npn1^Sema−/− or Npn2^−/− alone. The quantification method is described in the Methods section. No bracket indicates a relationship of P>0.05; **, P<0.01; ***, P<0.001. (D–E) By E13.5, several nerve bundles project towards the central cornea. The presumptive corneal epithelium is innervated (arrowhead), and some nerve bundles project into ectopic regions near the lens vesicle (arrow) and between the lens and optic cup (asterisks). Scale bar: 100 µm. oc, optic cup; c, cornea.