Fig. 2
Effects of PM2.5 exposure on DNA damage in ovarian follicles: Female mice were exposed to concentrated ambient PM2.5 or filtered air as described for Fig. 1 and ovaries were processed for immunostaining for γH2AX as described in Methods. The graphs show the means ± SEM percentages of follicles with γH2AX-positive granulosa cells (A) or oocytes (B). Representative photomicrographs taken with 40 × objective show secondary follicles (S) with γH2AX-positive, brown-stained nuclei of granulosa cells and oocyte (yellow arrow; the nucleus does not appear round because of fixation artifact) and primordial and primary follicles with γH2AX-positive oocytes (red arrows). PM2.5 exposure significantly increased the percentages of primary and secondary follicles with γH2AX-positive granulosa cells (A) and of secondary follicles with γH2AX-positive oocytes (B). *P < 0.05 compared to air controls. N = 6–7/group. Scale bars, 50 μm