For ChIP-seq experiments, nuclei were isolated from mouse olfactory epithelium and native ChIPs were performed using H3K79me3 antibody. For DHS-seq, nuclei were isolated from mouse olfactory epithelium and treated with 20U Dnase (DNase I, Invitrogen) for 3 min, reactions were stopped with EDTA and proteinase K treated overnight. Regions 100-500 bp were excised from agarose with Qiagen kit and library was constructed by Nugen Ultralow DR kit and PCR amplified for 25 cycles. 1 microgram library was hybridized to custom designed capture probes (Nimblegen SeqCap Design) targeting olfactory receptor enhancers, and capture was performed per the manufacturer's instructions. After elution from probes, library was amplified using Truseq adapters for 18 cycles using Phusion DNA Polymerase and sequenced. ChIP DNA was sonicated for 180 seconds on Covaris S220 and library constructed using Nugen Ultralow DR kit.