ATAC seq of Drosophila acessory glands
Each sample was collected from 15 males 48 hours after eclosion.  Tissues were lysed in 200l of ATAC-seq lysis buffer (10mM Tris-HCl, 10mM NaCl, 3mM MgCl2, 0.1% IGEPAL CA-630) and manually homogenized 25 times with a plastic pestle, followed by a 1-min incubation on ice, repeated twice.  Following homogenization, the samples were pelleted at 4C (100g for 10min) to recover the nuclei.  We removed the supernatant and washed the pellet in 200l of the lysis buffer.  The nuclei preparation was filtered through a 40-m cell strainer and washed with another 200l of lysis buffer.  The purified nuclei were isolated by centrifugation at 1,000g for 10min at 4C.  After removing the supernatant, 12.5l Nextera Tagment DNA Buffer (Illumina), 11.25l ddH2O and 1.25l Tn5 Transposase were added to the purified nuclei to tagment the DNA.  Libraries were then processed using the workflow of (Buenrostro et al., 2015) with a final upper and lower size-selection using SPRI beads with bead-to-sample ratios of 0.4 and 1.7, respectively.