title: GSM5841337: 4C_HOXD4_HH18_PT_rep1; Gallus gallus; OTHER
library_construction_protocol: Circular chromosome conformation capture (4C-seq) was performed as described in (Noordermeer et al., 2011). Briefly, tissues were isolated in PBS supplemented with 10% Fetal Calf Serum and dissociated to single cell by collagenase treatment. Samples were fixed in 2% formaldehyde, lysed, and stored at −80°C. Samples were primarily digested with NlaIII (NEB, R0125L) followed by ligation under diluted conditions. After decrosslinking and DNA purification DpnII (NEB, R0543M) was used for the second restriction. All ligation steps were performed using highly concentrated T4 DNA ligase (Promega, M1794). For each viewpoint approximately 1μg of DNA was amplified by using 12 individual PCR reactions. Libraries were constructed with inverse primers for different viewpoints (see Table 5) containing Illumina Solexa adapter sequences and sequenced on an Illumina HiSeq 2500 sequencer, as single-end reads (read length 100 base pairs or 80 base pairs). In some samples 4-bp barcodes were added between the adapter and each specific viewpoint to allow sample multiplexing.