Extended Data Fig. 1: Histone methylation is uniform while histone acetylation is non-uniform in the wing disc.
From: Nuclear position and local acetyl-CoA production regulate chromatin state
(a) Histone methylation marks H3K9me1, H3K9me2, H3K9me3, and H3K36me3 show a roughly uniform distribution in the wing disc as visualized by immunostaining. Euchromatin-associated H3K36me3 is slightly enriched in the disc rim and heterochromatin-associated H3K9me2 is slightly decreased in the wing disc rim, suggesting more open chromatin in the rim. (n = 7, 14, 12, and 20 discs from left to right). (b) Elevated rim H3K18ac is also visible with two additional independent antibodies. (n = 19 and 20 discs from left to right). (c-d) H3K18ac (c) and H4K8ac (d) are enriched in the wing disc rim throughout the third-instar larval stage (early to late L3). (c, n = 14, 20, and 11 discs from left to right; d, n = 18, 17, and 11 discs from top to bottom). (e) Images of peripodial nuclei suggest enrichment of H3K9ac, H3K27ac, H3K18ac, H4K8ac, and H3K36me3 as well as total acetylated lysine (ac-K) in euchromatin as their immunosignals are excluded from highly compacted DNA regions indicated by high DAPI signal, whereas H3K9me2 and H3K9me3 are associated with heterochromatin, indicated by high DAPI signal. H3K9me1 is present throughout the nucleus. (n = 7, 8, 16, 12, 13, 7, 14, 12, and 20 discs from top to bottom). (f) Higher magnification view of main Fig. 1h where the apical surface is marked with a dotted white line. (g-g’) Enrichment of lipoproteins (lpp) on outward-facing membranes was validated by a second lpp antibody (#2). Dashed line in (g) indicates the position of the cross-section shown in (g’). (n = 15 discs). (h-h’) The formation of a new rim of H3K18ac-positive nuclei after elimination of the tsh expression domain via reaper expression correlates with high levels of lpp on outward-facing membranes. Cell death was induced by temperature-sensitive expression of reaper for 1 day at 29 °C. Dashed line in (h) indicates the position of the cross-section shown in (h’). (n = 5 discs). (i-j) Nuclei in Rok loss-of-function (RNAi) clones in the wing pouch move further basally than normal, where they come in proximity to the tissue surface and have high H3K18ac. Representative images in (i), quantified in (j). Nuclei from control cells and Rok loss-of-function clones are indicated in black and green, respectively. (n = 23 discs). Box plots: center line (median), box limits (1st and 3rd quartiles), whiskers (outer data points).