mini-INTACT reveals social isolation-induced epigenetic changes in Drosophila dopaminergic neurons

We introduce a more sensitive method for purifying specific cell-types from small numbers of fly heads for epigenomic analysis: a method we call ‘mini-INTACT’. We modified the INTACT method in Drosophila [Henry G. L. et al., Nucleic Acids Research, 2012, 1–14] to enable purification of genetically tagged rare cell types from Drosophila brain requiring ~50-100 fold less material. We used male fruit flies as a model to examine the effects of social-isolation vs. social-enrichment on the epigenome and transcriptome of dopaminergic neurons defined by expression of the TH-GAL4 driver. Using ChIP-seq on mini-INTACT purified nuclei, RNA-seq and bioinformatic analysis, we identify regulation of the transcriptome and behavior by Activity Related Genes who’s expression is induced by social enrichment. Genome wide occupancy profiling for histone modification marks by high throughput sequencing. Two or three biological replicates were used for each condition. Corresponding input DNA was used as control (ChIP-seq). Expression profiling by high throughput sequencing on FACS purified dopaminergic neurons isolated from group-housed and single-housed fruit fly adult male brains. Three biological replicates were used for each condition (RNA-seq).