Chromatin domains of embryonic cells in vivo show extensive differences from those in cell cultures. (a) The number of DHSs per megabase is plotted for DHSs from stage 5 embryos (white), stage 14 embryos (gray) and Kc cells for DHSs mapping to each of the five chromatin states annotated in Kc cells (red, yellow, green, blue, and black). A much larger proportion of DHSs in Kc cells map to active chromatin than to repressive chromatin, while DHSs from stage 5 and 14 are divided among the Kc domains. (b) The log ratio of embryo to Kc DHSs/Mb shown in panel (a), showing the enrichment of embryonic DHSs at regions that represent repressed chromatin in Kc cells. These enrichments suggest extensive plasticity between the two Drosophila systems. (c) An example of chromatin that is active in Kc cells but not in embryos. Plotted for stage 5 embryos and Kc cells is the DNaseI density and colored chromatin state (red and yellow = active, blue and black = repressive). (d) An example of chromatin that is active in embryos but not in Kc cells.
Thomas et al. Genome Biology 2011 12:R43 doi:10.1186/gb-2011-12-5-r43