Figure 2. Transcriptomic profiling of young and old adult fly brains.

(A) Principle Component Analysis (PCA) of young (0–2 d post-eclosion) and old (21–25 d) H3.3A^null and H3.3^K36R fly heads, labeled by sex. (B) M/A plot comparing gene expression from mixed sex H3.3^K36R and H3.3A^null young fly heads. Red and blue dots represent differentially expressed genes (DEGs) that were significantly (adjusted p-value, p-adj < 0.05) up- or down-regulated, respectively. The number of DEGs in each direction is shown in the upper and lower corners. (C) M/A plot of mixed sex H3.3^K36R vs. H3.3A^null transcripts from old adults. Labeling and significance as per panel B. (D) Venn diagram comparing overall number of DEGs (p-adj <0.05) between H3.3A^null and H3.3^K36R genotypes, young and old mixed sex fly heads. (E) Venn diagram of DEGs (p-adj < 0.05 and Log₂ Fold-change ≥ |1|) from female H3.3^K36R (young or old) versus aged (20 d) female Chd1 fly heads. Data for Chd1 provided by [25].