The reference genome of Ectropis grisescens
Hi-C library was prepared from DNA of a fifth instar larva. The larva was cut into pieces, washed in precooled phosphate buffered saline and vacuum infiltrated in nuclei isolation buffer. The crosslinking-reaction was conducted in 2% formaldehyde solution and stopped by supplementing glycine and additional vacuum infiltration. The fixed tissues were grinded with liquid nitrogen into powder and resuspended in nuclei isolation buffer to get a suspension of nuclei. Then, the purified nuclei were digested with 100 units restriction enzyme Dpn II and the DNA ends were labelled with biotin-14-dCTP. T4 DNA polymerase was used to remove biotin-C from non-ligated fragment ends. DNA was sheared to fragments of 300600 bp by sonication, and then was blunt-end repaired and A-tailed before being purified through biotin-streptavidin-mediated pull down. Finally, the Hi-C library was quantified and sequenced on an Illumina Hiseq platform.