Figure 6

Elevated apoptotic activity and lipid deposition in the Tg ovarian follicles. TUNEL assay on 6-month-old WT (a), 4-month-old Tg (b) and 6-month-old Tg (c) ovaries was performed. (d) Agarose gel electrophoresis to detect DNA fragmentation using genomic DNA from 6-month-old WT (lane1), 2-month-old Tg (lane 2), 4-month-old Tg (lane 3) and 6-month-old Tg (lane 4) ovaries. A necrotic control was also included (lane 5). No difference in DNA migration pattern was observed between samples from WT and 2-month-old Tg ovaries (lanes 1 and 2). Elevated apoptosis as exhibited by the ‘ladder’ DNA pattern became apparent in Tg ovaries from 4 months of age (lane 3). In 6-month-old Tg ovaries, low-molecular-weight DNA fragments were present as a smear pattern, indicating that necrosis is prominent at this stage (lane 4). (e–h) Abnormal adipogenesis in 4-month-old Tg follicles. (e) is a representative lacZ-stained section showing a large cystic follicle (>400 μm in diameter, which is equal to the size of a healthy antral follicle). Oil-Red-O staining shows these cystic follicles were essentially filled with lipid drops (arrows, f and g). (h) Expression of adipogenic marker gene PPARγ in 2, 4 and 6-month-old ovaries from WT and Tg females was examined by Q-PCR. For all experiments, each sample input was normalized by GAPDH expression levels. PPARγ expression was presented relative to that of the 2-month-old WT ovaries as the mean±S.E.M. of three independent experiments. Data were analyzed using a one-way t-test. Genotype and ovarian age are indicated in the lower left corners of the corresponding photographs. Scale bars, 100 μm