Fig. 3. The effect of repeated ovarian stimulation on mouse ovarian apoptosis.

(A) TUNEL assay was used to confirm the occurrence of apoptosis in OS and RS group mice ovaries. Apoptosis is indicated by the presence of green fluorescence. (B) The number of follicles with apoptosis as a percentage of the total number of follicles was used to calculate the incidence of apoptosis. Apoptosis was only confirmed in the antral follicle, Graffian follicle, and corpus luteum in the OS group. Only the antral and Graffian follicles in the RS group showed signals of apoptosis. No apoptosis occurred in corpus luteum of RS group. OS, once stimulation; RS, repeated stimulation; AF, antral follicle; GF, Graffian follicle, CL, corpus luteum.