Figure 1.

Affinity purification of neuronal nuclei from Drosophila melanogaster with the INTACT system. INTACT introduces into Drosophila genome an NTF gene consisting of 3xFLAG, BLRP (biotin ligase recognition peptide, a preferred substrate for BirA), mCherry, and RanGap (expressed in the cytoplasm and outer nuclear envelope). The NTF gene was expressed under the control of neuron-specific gene (Elav) promoter. (a) Three purified nuclei bound to an anti-Flag-coated bead (the large circle). Scale bar: 10 μm. (b) Detection of mCherry (red) epitope and endogenous Elav (green) expression in a fixed stage 15 embryo (Elav-Gal4>UAS-NTF). Scale bar: 30 μm. (c) The expression levels of neuron-specific genes are significantly higher compared with other tissue-specific genes in the purified neuronal nuclei. All P-values are <0.01 (Wilcoxon's rank-sum test). (d) Heatmap shows the profiles of core HMs in the promoter regions (±1 kb of TSS) of different tissue-specific genes in the purified neuronal nuclei. Genes are sorted descendingly by the expression level within each tissue