Identification of E93 binding sites in Drosophila melanogaster. Identification of E93 binding sites in Drosophila melanogaster

Chromatin immunoprecipitation was performed with modification of the protocols described before (Lee et al., 2006; Lilja et al., 2007). Briefly, the chorion was removed from 12-hour old embryos, cross-linked using 2% paraformaldehyde and resuspended in storage buffer (50mM Tris-HCl pH8.0, 1 mM EDTA). Embryos were then lysed in SDS-lysis buffer (1.0 ml 5 M NaCl, 2.5 ml 1 M Tris-HCl pH 8.0, 0.5 ml 0.5M EDTA, 2.5 ml 10 % SDS), resuspended in SDS-lysis and Triton buffer (1.0 ml 5 M NaCl, 5.0 ml 1 M Tris-HCl pH 8.0, 0.5 ml 0.5M EDTA, 2.5 ml Triton X-100, protease inhibitor cocktail) and sonicated on ice to an average length of 350 bp. The resulting sheared chromatin (25Izg) was subjected to immunoprecipitation using anti-Myc antibody (Santa Cruz) as described previously (Lee et al., 2006). ChIP-sequencing libraries were constructed following manufactureras instructions (Illumina). The resulting DNA libraries were sequenced using Illumina platform (University of Massachusetts Medical School Core Facility).