Fig. 4. Sst and Npy are common target genes downstream of MTG8 and LHX6.

a Experimental design for identification of downstream genes requiring MTG8 and/or LHX6 function within the MGE-derived cortical interneuron lineage using transcriptomic profiling of purified cells from E14.5 neocortex. b Volcano plots showing statistical significance (−10x log₁₀ P values) against fold change (log₂ fold change) between control and mutant MGE-derived cells for Mtg8 and Lhx6. Negative Log₂ fold change values indicate decreased expression in mutants compared to controls. Positive Log₂ fold change values indicate increased expression in mutants compared to controls. DEGs with a padj <0.05 are shown in black/blue/red. Common DEGs in both Mtg8 and Lhx6 mutants are indicated in blue (downregulated) and red (upregulated). c, d Heatmaps showing common downregulated (c) and common upregulated (d) genes in Mtg8 and Lhx6 mutant animals. Sst and Npy are among the top downregulated genes in both mutants. e Representative coronal sections through the embryonic telencephalon at the level of the developing septum at E16.5 showing expression of Npy in control, Mtg8^−/− and Lhx6^−/− mutant animals. An area of the developing neocortex is shown at higher magnification in e’–e”’. Arrows indicate migrating Npy-expressing cortical interneurons in the SVZ/IZ. Quantification represents Npy^+ve cells in the developing neocortex in the SVZ/IZ areas underneath the CP (area indicated in e”). Reduced expression of Npy can be seen in the developing basal ganglia (arrowheads) and neocortex (arrows) of both mutants. n = 3 embryonic brains for each genotype. One-way ANOVA followed by Uncorrected Fisher’s LSD tests. ****P < 0.0001, **P = 0.0042. Graph shows mean ± SEM. Source data are provided as a Source Data file. Scale bars: 250 μm and higher magnification 60 μm.