Fig. 4

a Effects of heat stress on apoptosis in ovarian granulosa cells. Representative photomicrographs of Hoechst and TUNEL-stained granulosa cells from ovaries of control and heat-stressed mice. Ovarian heat treatment was carried out in a 37 (Con) or 41 °C (HS) water bath for 2 h. After heat stress, granulosa cells were collected from the ovaries and cultured for another 24 h. b The percentage of trypan blue-positive granulosa cells from the ovaries of mice in the control (Con) and heat stress (HS) treatments. c The ovaries were exposed to a 37 (Con) or 41 °C (HS) water bath for 2 h and then the granulosa cells were collected and cultured for either 0 or 24 h. Thereafter, the cells were collected and the expression of HSP70, Bim, caspase-3 and cleaved caspase-3 were detected in the cell lysates. d Relative protein levels of granulosa cells before heat treatment. e Relative protein levels of granulosa cells 24 h after heat treatment. *indicates P < 0.05 compared with the control