Epigenetic blocking of an enhancer region controls irradiation-induced proapoptotic gene expression in Drosophila embryos.

ABSTRACT: Drosophila embryos are highly sensitive to gamma-ray-induced apoptosis at early but not later, more differentiated stages during development. Two proapoptotic genes, reaper and hid, are upregulated rapidly following irradiation. However, in post-stage-12 embryos, in which most cells have begun differentiation, neither proapoptotic gene can be induced by high doses of irradiation. Our study indicates that the sensitive-to-resistant transition is due to epigenetic blocking of the irradiation-responsive enhancer region (IRER), which is located upstream of reaper but is also required for the induction of hid in response to irradiation. This IRER, but not the transcribed regions of reaper/hid, becomes enriched for trimethylated H3K27/H3K9 and forms a heterochromatin-like structure during the se

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC2901920 | biostudies-literature | 2008 Apr

REPOSITORIES: biostudies-literature