Nucleation-dependent propagation of Polycomb modifications emerges during the Drosophila maternal to zygotic transition

ABSTRACT: The manuscript associated with these datasets seeks to address the timing of acquisition of chromatin modifications associated with Polycomb group (PcG) function during the maternal-to-zygotic transition of Drosophila melanogaster. PcG modifications including mono- and tri-methylation of Histone H3 at Lysine 27 (H3K27me1, me3) and ubiquitylation of H2A at lysine 118 (H2Aub) were measured by ChIP-seq in precisely staged embryo collections spanning large scale zygotic genome activation (ZGA), over nuclear divisions NC13 and three timepoints in NC14 (NC14-early, -mid, and -late). Additionally, marks associated with active transcription, including mono- di- and tri-methylation of Histone H3 at Lysine 4 (H3K4me1, me2, me3), RNA Pol2 phosphorylated at serine 5 of the C-terminal domain heptapeptide repeats, and acetylation of Histone H3 at Lysine 27 (H3K27ac) were measured at NC14. We additionally measured genomic localization of the H3K27me3 methyltransferase, Enhancer of zeste (E(z)), and of three factors known to bind Polycomb Response Elements, Pho, Combgap, and GAGA-Factor (GAF), by generating GFP chimeras to these proteins using CRISPR/Cas9 and performing ChIP against the GFP tagged proteins. Data for these GFP-ChIP-seq localization experiments is from embryos collected during NC14. To test for the contribution of DNA binding factors to the establishment of PcG modifications, we additionally measured deposition of H3K27me3 in embryos where GAF was sequestered from nuclei using Jabba Trap (JT-GAF), and measured H3K27me3, H2Aub, E(z), and RNA Pol2 in embryos from zelda mutant germline clones staged at mid-NC14. Negative control ChIP-seq datasets are provided in the form of anti-GFP ChIP in wild-type embryos that express no GFP tagged protein.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE299311 | GEO | 2025/07/03

REPOSITORIES: GEO