Fig. 2. RNAi knockdown of Lhx6 blocks the rescue of PV- or SST-expressing cells by Nkx2.1. (A) The results of RT-PCR for Nkx2.1 (lanes 1 and 2) and Lhx6 (lanes 3 and 4) from the MGE-like region (MGE^*) of an E12.5 Nkx2.1^-/- slice that was electroporated with pGFP control vector (lanes 1 and 3) or pNkx2.1-GFP (lanes 2 and 4). Lhx6 (422 bp band in lane 4) is induced in the Nkx2.1-transfected slice. (B,C) Transfected cells from the MGE^* of Nkx2.1^-/- slices that were cultured from E12.5+1DIV, then transplanted into the parietal cortex of a neonatal mouse in vivo and evaluated in 40 µm sections at P30. The neuron in B was from a transplant that received pNkx2.1+ scramble RNAi control, and co-immunolabels for LHX6 (red) and somatostatin (SST, blue pseudocolored from Cy5 signal). Transfection of pNkx2.1-GFP + shLhx6 RNAi blocks the induction of Lhx6 and blocks rescue of the SST+ phenotype (C). Note that endogenous SST+ GFP-negative cells in the mouse cortex co-label for LHX6. (D) Quantification of the effect of shLhx6 RNAi on the Nkx2.1 rescue of PV+ and SST+ interneuron fate (n=3 donor samples for each condition transplanted into separate pups, Student's t-test, ^**P<0.01, ^*P<0.03).