Getting poster data...
Jia-Ming Chang, Giacomo Cavalli (Institute of Human Genetics (IGH), UPR 1142, CNRS 141, rue de la Cardonille, 34396 Montpellier Cedex 5, France)The modENCODE project has provided an updated map of the Drosophila melanogaster (Dmel) regulatory genome based on the location of 84 transcription-related factors (TRFs). The TRFs binding regions are separated according to the frequency of their TRF occupancy into 3 categories: HOT, WARM, and COLD which are targeted by >=14, 4–13 and 1–3 TRFs, respectively. We produced the high-resolution chromatin contact map of Dmel with a 1kbp resolution by Hi-C approach. Then, we divided the TRFs binding regions into 5 categories based on size and then analyzed their contact intensity(fig). Interestingly, the edges of COLD and WARM regions tend to have higher contact intensity than HOT regions (HOTs). This reverse relation between TRFs occupancy and contact intensity is more significant for larger bins. This observation suggests that HOTs are folded into more open, chromatin conformations that engage in fewer local contacts, whereas COLDs are folded into more dense conformations. It was reported that HOTs are significantly less conserved than WARM/COLDs. Our data thus indicate that higher densities of 3D chromatin contacts may impose stronger evolutionary constraints to DNA sequenc