GSE210971
Role of RNA polymerase II "pausing" in Drosophila development
According to previous studies, during Drosophila embryogenesis, RNA polymerase II is recruited to promoters at developmental stages preceding the stages of active transcription of genes. This work is aimed at exploring whether this mechanism is used during Drosophila metamorphosis. We performed ChIP-Seq analysis using antibodies to various modifications of RNA polymerase II (total, Pol II CTD Ser5P and Pol II CTD Ser2P), as well as to subunits of NELF, DSIF, PAF complexes and Brd4/Fs(1)h that control transcription elongation. We found that like in mid-embryogenesis during metamorphosis, promoters bind RNA polymerase II in the "paused" state preparing for activation at later stages of development. During mid-embryogenesis, RNA polymerase II in "pause" is phosphorylated at Ser5 and Ser2 of Rpb1 CTD and binds NELF, DSIF, and PAF complexes, but not Brd4/Fs(1)h. During metamorphosis, the "paused" RNA polymerase II complex includes Brd4/Fs(1)h in addition to NELF, DSIF, and PAF. The RNA polymerase II in this complex is phosphorylated at Ser5 at Rpb1 CTD, but not at Ser2. Overall design: Whole embryos, larvae and prepupae were staged and collected for the ChIP-Seq experiments with antibodies against Rpb3, Pol II Ser2P, Pol II Ser5P, NELF-E (NELF complex), Spt5 (DSIF complex), PAF1 (PAF complex) and Brd4/Fs(1)h