Fig. 3

ESCs-sEVs promoted the development of follicles. A H&E staining of ovaries. A (e–h) Magnifications (× 100) of the red squares in A (a–d) (× 200), respectively. A (j) Primordial follicle. A (k) Primary follicle. A (l) Secondary follicle. A (m) Mature follicle. A (n) Atretic follicle. B Summary of follicles in each group. C Apoptosis was measured by TUNEL staining. The cell nuclei were stained by DAPI (blue fluorescence), and the apoptotic cells were stained with Cy3 (red fluorescence). D The percentage of TUNEL-positive granulosa cells was measured in each group. Apoptotic cells were increased in the CTX + BUS group and decreased in the ESCs-sEVs group. Scale bar = 75 μm E Western blotting analysis detected the expression of FSHR and a protein related to apoptosis in ovarian tissue. Data are presented as the mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001