Fig. 6

Loss of Tcf3/12 in the ventral telencephalon results in an increased MGE progenitor region and does not impact regional patterning markers. Multiple markers were used to investigate the different progenitor populations within the MGE: Gsx1 is expressed in progenitors in the VZ in the MGE and LGE (A-B), Gsx2 in a high dorsal to low ventral gradient in LGE/MGE progenitors (C-D), Olig2 in LGE/MGE progenitors (E-F), Ascl1 in LGE/MGE progenitors in the VZ and SVZ (G-H), and Nkx2.1 is expressed in progenitors defining MGE boundaries (I-J). Expression of all MGE progenitor populations examined show expression spanning the larger MGE in the dcKOs, while general patterning is maintained. MGE area quantified by area of Nkx2.1 expression (K). BrdU pulses were performed 30 minutes before E15.5 dissection (L-M). Boxes in L and M refer to approximate areas for high magnification shown in N and O.  There was no difference in the number of BrdU+ cells in the VZ when controlling for MGE size, but a decrease in BrdU+ cells in the SVZ of the MGE (N-O, quantification P,Q). Scale bars M = 200 μm (for A-M), O= 100 μm (for N-O). MGE = medial ganglionic eminence, LGE = lateral ganglionic eminence, STM = Striatum