DEV038083 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure S1 -

  Fig. S1. Molecular marker expression can distinguish SINs from MSNs in the striatum. (A,B) Lhx6 and Lhx7 are not expressed in the LGE-derived MSNs. Confocal optical sections from Lhx7^+/nlacZ (A) and Lhx6^nlacZ (B) striatum double immunostained for β-gal (green) and the MSN marker DARRP-32 (red). Note that both Lhx7 and Lhx6 are excluded from MSNs. The boxed areas are presented at higher magnification in the insets. (C) Striatal GABAergic and cholinergic populations are generally distinct. Confocal optical sections from a Gad67^+/GFP adult striatum immunostained with antibodies specific against ChAT and the Gad67 reporter GFP. Arrow points to the cell shown at higher magnification in the inset.

• Supplemental Figure S2 -

  Fig. S2. β-gal⁺ cells display a similar pattern of colonisation of the striatum, but different morphological features in Lhx7^+/nlacZ and Lhx7^nlacZ/nlacZ embryos. (A-D) Coronal sections of the striatum of Lhx7^+/nlacZ (A,C) and Lhx7^nlacZ/nlacZ (B,D) E15.5 mouse embryos (A,B) and adult mice (C,D) processed for β-gal histochemistry. Boxed areas are presented at higher magnification in the insets. (E) Quantification of the density and the relative proportions of ‘large nuclei’ (cholinergic) and ‘small nuclei’ (GABAergic) β-gal⁺ cells in the striatum of control and mutant mice. Note that in contrast to controls, in Lhx7^nlacZ/nlacZ animals most of the β-gal⁺ cells reaching the LGE have small and weakly stained nuclei.

• Supplemental Figure S3 -

  Fig. S3. In Lhx6-Cre;Rosa26-StopYFP animals expression of Cre recapitulates that of Lhx6. (A-F) Confocal optical sections from Lhx6-Cre;Rosa26-StopYFP brain immunostained for YFP and Lhx6. Images show the different areas analysed, i.e. cortex (ctx; A), dentate gyrus (dg; B), striatum (str; C), medial septum (ms; D), the diagonal band and the magnocellular preoptic nucleus (db/mcpo; E) and the lateral globus pallidus (lgp; F). In these areas, virtually all Lhx6⁺ cells co-express YFP. The arrow in A points to the cell presented at higher magnification in the inset. Note that in areas hosting cholinergic neurons, the subpopulation of large YFP⁺ cells is generally negative for Lhx6 (arrowheads in C,D,E). Neurons of similar morphology are usually positive for ChAT.

• Supplemental Figure S4 -

  Fig. S4. Marker gene expression in chick embryo spinal cord upon electroporation of Lhx7/Isl1. (A,B) Sections of HH stage 26 chick spinal cord electroporated (+ side) with Lhx7 and Isl1 (A1,2) or Isl1 alone (B1,2) and immunostained for GFP (A1,B1) and Chx10 (A2) or MNR2 (B2). A1, B1 and A2, B2 correspond to the same sections. Note that co-electroporation of Lhx7 and Isl1 blocks the induction of dorsal V2 IN observed upon electroporation of Lhx7 and that electroporation of Isl1 alone is not sufficient to generate ectopic MNs in the dorsal neural tube.

• Supplemental Figure S5 -

  Fig. S5. Comparison of marker gene expression in the VZ and SVZ/MZ of the MGE. (A-D) MGE sections of E13.5 GAD67-GFP;Lhx6^β-gal embryos immunostained for GFP (reporter of GAD67 expression; green), Lhx6 (red) and β-gal (reporter of Lhx6; blue). The higher magnifications in B, C and D correspond to the boxes shown in A. Note that virtually all Lhx6⁺ cells in the mantle zone express GFP. (E-G) Double immunostaining of E12.5 MGE sections from wild-type (E,G) or Lhx7^nlacZ (F) embryos with antibodies for Ki67 (red) and either Lhx6 (E), β-gal (reporter of Lhx7) (F) or Isl1 (G).Generally, all three LIM homeodomain proteins are expressed in postmitotic neurons. However, a small number of Lhx6⁺ Ki67⁺ cells can be seen mostly at the border between the SVZ and mantle zone.