Figure 3

Arhgef7 is required for axon formation in the cortex. (a) The expression of Arhgef7 in the cortex from Arhgef7^fl/+; Emx1^Cre/+ (+/−) or Arhgef7^fl/fl; Emx1^Cre/+ (−/−) E17.5 embryos was analyzed by Western blot. Analysis of GAPDH expression confirmed that the loading of comparable amounts of protein. Numbers indicate the molecular weight in kDa. (b) Cultured neurons from the cortex of Arhgef7^fl/+; Emx1^Cre/+ (+/−) or Arhgef7^fl/fl; Emx1^Cre/+ (−/−) E17.5 embryos were stained at 3 d.i.v. (stage 3) with an anti-Arhgef7 (green), an anti-MAP2 (red) and the Tau-1 (blue) antibody. (c) The formation of axons was analyzed at 3 d.i.v. by counting the number neurons without an axon (0, black) with a single axon (1, gray), and with multiple axons (>1, white). (ANOVA, Student’s t-Test, ***p < 0.005, n = 3 with at least 50 neurons counted per experiment). The scale bar is 20 μm. (d) Coronal sections from the brains of E17 Arhgef7^fl/fl; Emx1^Cre/+ (Arhgef7−/−) or Arhgef7^fl/+; Emx1^Cre/+ (Arhgef7+/−) mouse embryos were stained with antibodies specific for the neurofilament medium chain (NF, green) and a nuclear marker (Hoechst 33342, blue). The scale bar is 100 μm.