Fig. 6. Shh containing a point mutation at the site of N-terminal fatty-acylation does not induce ectopic expression of Dlx2 or severe brain deformities in the mouse telencephalon in vivo. E9.5 mice were injected with retroviruses containing alkaline phosphatase, dicistronic with either full-length wild-type Shh or Shh containing a mutation of the N-terminal fatty acylated residue (Cys-24). Embryos were then harvested at E12.5, coronally sectioned through the telencephalon and processed for in situ hybridization with antisense Dlx2 RNA (A,C,E,F,H) or alkaline phosphatase activity (B,D,G,I,J). Arrows with dotted line indicate ectopic Dlx2 induction (A,C,E); arrows in B,G,I,J indicate virally infected clusters. Sections infected with wild-type Shh virus; (F-I) sections infected with C24S virus. Adjacent sections are as follows: A and B, C and D, E and J, F and G, and H and I. (K,L) An enlarged brain phenotype results in embryos infected with wild-type Shh virus (Shh, n=37/42). Arrows indicate the enlarged region of the forebrain. (M,N) Embryos injected with C24S Shh virus appear normal (C24S, n=38). LGE indicates the location of the lateral ganglionic eminence, where Dlx2 is normally expressed.
