To perform the ChIP assays with mouse embryonic tissues, we dissected E16 hypothalamuses. The tissues were dissociated completely, fixed by 1% formaldehyde for 10 min at room temperature, and quenched by 125 mM glycine. Next, cells were washed with PBS and lysed with lysis buffer (0.5% SDS, 5 mM EDTA, 50 mM Tris-HCl, pH 8.0, Protease inhibitor cocktail) and were subjected to sonication using bioruptor. Supernatant was incubated with Dlx1 homemade antibody and protein A agarose beads to precipitate the hexamer/chromatin complex for overnight at 4°C. ChIP-seq libraries were constructed with the llumina's instructions accompanying the DNA Sample Kit. Libraries were sequenced on the Genome Analyzer following the manufacturer's protocols.