Figure 2. Immunofluorescent localization of histone modifications in fully-grown GV stage oocytes of young and aged female mice. Left panels: Shown are single confocal sections of the nucleus (GV). Left-most column are examples of oocytes with a non-surrounded nucleolus conformation (NSN = relaxed chromatin) and the right most column are micrographs of the surrounded nucleolus conformation (SN = contracted chromatin). No differentiation was made between these conformations for further analyses. Confocal settings were the same within each technical replicate. Stains used interchangeably to visualize DNA were YoYo1 Iodide or DRAQ7. Scale bar = 50 µm. Right panels: Shown are boxplots of the integrated density for each antibody (i.e. sum of all pixels above background; left) and variance of mean integrated density (right). The p-values are presented in the top left corner of each boxplot. Young mice = 10-13 weeks. Aged mice = 69-70 weeks. A. Data for H3K9me2 from four trials representing 79 oocytes from 8 young mice and 52 oocytes from 16 aged mice. B. Data for H4K5ac from four trials representing 87 oocytes from 9 young mice and 29 oocytes from 13 aged mice.