Fig. 4.

Loss of Nf2 reduces glutamatergic guidepost neurons. (A,A′) In control embryos at E15.5, Calretinin⁺ guidepost neurons reside at the midline cortical plate (CP). (B,B′) Fewer Calretinin⁺ neurons are found in Nf2^F/F;Emx1-Cre midline, especially at the region where GW fibers remain attached to the pia (B′, arrowhead). (C,C′) In controls, Sox2⁺ neural progenitor cells (NPCs), Tbr2⁺ intermediate progenitors and Calretinin⁺ neurons reside at the ventricular zone (VZ), subventricular zone (SVZ) and CP, respectively. (D,D′) In the midline of Nf2^F/F;Emx1-Cre mice, Tbr2⁺ intermediate progenitors intermingle with Calretinin⁺ neurons (arrowheads). (E-F′) BrdU was administered at E13.5, and embryos were harvested 48 h later. Many BrdU-labeled cells in controls are Calretinin⁺ (E,E′, yellow cells, arrowhead). In Nf2^F/F;Emx1-Cre embryos, most BrdU-labeled cells remain as VZ NPCs or Tbr2⁺ intermediate progenitors (F,F′) and fewer of them have differentiated into Calretinin⁺ neurons (F′, yellow cells, arrowheads). Panels labelled with primes are the magnified view of the boxed areas in corresponding panels. Scale bars: 100 µm.