Research Paper Volume 12, Issue 2 pp 1610—1623

Melatonin ameliorates the advanced maternal age-associated meiotic defects in oocytes through the SIRT2-dependent H4K16 deacetylation pathway

Figure 5. Effects of H4K16 acetylation on kinetochore–microtubule attachment and meiotic apparatus in mouse oocytes. (A) H4K16 wild-type (WT) and mutant-injected oocytes at metaphase stage were labeled with α-tubulin antibody to visualize spindle (green), CREST to detect kinetochore (purple), and co-stained with Hoechst 33342 for chromosomes (blue). Representative confocal sections are shown. Scale bars: 5 μm. Lost attachments were frequently detected in oocytes injected with H4K16Q mutant. (B) Quantitative analysis of K-MT mis-attachments in WT and H4K16 mutant-injected oocytes. Data are expressed as mean percentage ± SD from three independent experiments in which approximately 30 oocytes were analyzed. (C) WT and H4K16 mutant-injected oocytes were stained with α-tubulin antibody to visualize spindle (green) and counterstained with propidium iodide to visualize chromosomes (red). Representative confocal sections are shown. Scale bars: 50 μm. (D) Quantification of WT and H4K16 mutant-injected oocytes with spindle/chromosome defects. Data are expressed as mean percentage ± SD from three independent experiments in which around 115 oocytes were analyzed. *P<0.05 vs. controls.