GSE210427
Role of H3K4me1 and H3K27ac histone marks in aging Drosophila
Temporal and spatial gene expression patterns are regulated by enhancer-specific histone modifications H3K4me1 and H3K27ac. To better understand age-dependent alteration of these enhancer marks, we analysed their genome-wide profiles and compared against changes in gene expression in the head tissues harvested from young Day 10 and D50 male Drosophila. The genome-wide binding patterns of H3K4me1 and H3K27ac remain highly similar (>85%) during ageing with marginally higher signals for both marks in older Day 50 flies. Signals were significantly higher in Day 50 flies near the transcription start sites for H3K4me1 whereas for H3K27ac, signals were significantly higher in Day 50 flies globally. Interestingly, analysis using MACS bdgdiff identified “x” H3K4me1 and “y” H3K27ac differential peaks that correlated with distinct sets of age-dependent differential expressed genes (DEG). Most of the H3K4me1 differential peaks (percentage of x) are located within the gene body of DEGs that are associated with RNA and metabolic processes. On the other hand, majority of differential H3K27ac peaks (percentage of y) are located 5 kb upstream of TSS of DEG enriched for various immune responses. Our results suggest that while both enhancer marks do not undergo significant global reconfiguration during aging, they are likely to be involved in activating independent sets of genes through distinct transcription activators. Overall design: ChIP-sequencing of Drosophila heads isolated at day 10 and 50 of adult life.