Netrin1 Is Expressed at the Developing Ventral Chiasm
(A–D) Horizontal (A–B’’) and coronal (C–D’’) serial sections of E12.5 (A–A’’ and C–C’’) and E14.5 (B–B’’ and D–D’’) embryos at the level of the optic chiasm region stained by ISH for Netrin1 (red) combined with immunofluorescence for Tuj1 (green) to label retinal axons.
(E) Diagram summarizing the spatiotemporal expression of Netrin1 at the optic chiasm (red). RGC axons projecting to the brain (light green) or to the opposite optic nerve (dark green) are also represented. At E12.5, when RGC axons have not yet arrived at the chiasm, Netrin1 mRNA is expressed predominately in two patches on both sides of the ventral diencephalon. At E14.5, when axons are at the chiasm region, Netrin1 mRNA surrounds the optic tracts.