Expression of dLGE markers Sp8 and mTsh1 at E13.5. Sp8 is strongly expressed in the dLGE SVZ in controls at E13.5 (A, E). The level of expression is markedly diminished in Gsh2 mutants (B, F, arrows). The loss of Pax6 in Sey mutants results in ectopic pallial expression of Sp8 (C, G, arrowheads). In Sey/Gsh2 double mutant mice, this ectopic expression, although improved over the Sey single mutant phenotype, persists (D, H, arrowheads). At E13.5, mTsh1 is expressed in the dLGE SVZ and also the putative LCS migratory route (I, M, arrows). This expression is generally unaffected in Gsh2 mutants (J, N, arrows). Conversely, in the Sey mutant, ectopic mTsh1 expression is observed in both the pallium (K, O, arrowheads) and basally (K, O, arrows).This mispatterning is generally similar in the Sey/Gsh2 double mutants (L, P, arrows, arrowheads). Abbreviation: n numbers for each probe are as follows: controls, n = 4 [Sp8], n = 6 [mTsh1]; Gsh2−/−, n = 4 [Sp8], n = 4 [mTsh1]; Sey/Sey, n = 4 [Sp8], n= 5 [mTsh1]; Sey/Sey;Gsh2−/−, n= 5 [Sp8], n = 5 [mTsh1]. Scale bar: 200 μm.