GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_Readme.txtftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_FP_Pol2_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_TRI_Pol2_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_DMSO_PAF1_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_DMSO_Spt5_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_TRI_Spt5_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_FP_Spt5_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_FP_PAF1_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_TRI_PAF1_bg_corrected.bwftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE334nnn/GSE334998/suppl/GSE334998_DMSO_Pol2_bg_corrected.bwprimaryOK200GenomicsDrosophila melanogasterGenome binding/occupancy profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE334998GEOGSEfalseTranscription machinery clustering by Integrator synchronizes histone gene expressionNumerous components of the transcription machinery, including RNA polymerase II (Pol II), accumulate in high-concentration clusters at gene promoters. Whether these clusters assemble on demand during transcription or constitute regulatory units remains unclear. Examining the Drosophila histone locus—where histone genes normally transcribe exclusively during S phase—we unexpectedly found large clusters containing non-chromatin-bound Pol II and elongation factors outside of S phase. When transcription activates during S phase, P-TEFb drives an accelerated turnover of the cluster components. Dispersion of clusters through depletion of the Integrator complex endonuclease module causes histone transcription to have a diminished S-phase peak and instead occur ectopically throughout the cell cycle. We propose that clusters constitute gate-keeping hubs that maintain a poised machinery pool, restricting gene activation to defined temporal windows.2026/06/10GSE334998GSM9803169GSM9803168GSM9803181GSM9803180GSM9803167GSM9803166GSM9803165GSM9803164GSM9803163GSM9803162GSM9803161GSM9803160GSM9803159GSM9803158GSM9803179GSM9803157GSM9803170GSM9803178GSM9803156GSM9803155GSM9803177GSM9803176GSM9803154GSM9803175GSM9803153GSM9803152GSM9803174GSM9803173GSM9803151GSM9803172GSM9803150GSM980317122106334998Drosophila melanogaster