Interscapular BAT was isolated and processed for each sacrificed mouse. The tissues were immediately minced, crosslinked in 1 % formaldehyde/PBS. MED1 ChIPs were performed using EGS as an additional crosslinker. For each fat pad, material from 3-4 mice was used for sequencing. To prepare ChIP extracts, crosslinked tissue was suspended in a ChIP buffer containing 20mM Tris, 0.1% SDS, 1% Triton-100, 150 mM NaCl, 1 mM EDTA, protease inhibitors. Samples were incubated at 4 C for 10 min, and subjected to microtip probe sonication under conditions optimized for IP efficiency. Extracts were cleared of insoluble lipid by microfuge centrifugation at full speed followed by extract transfer to a new tube. The process was repeated until minimal lipid accumulated at the top of the extract after centrifugation. ChIP-Seq libraries were produced and sequenced according to Illumina protocols. Libraries were multiplexed for sequencing.