Research Paper Volume 13, Issue 2 pp 2118—2134

IGF2 improves the developmental competency and meiotic structure of oocytes from aged mice

IGF2 reduces the apoptosis and promotes the level of autophagy in aged mouse oocytes. (A) LC3 staining showing the extent of autophagy occurring in control and IGF2-treated oocytes. (B) Quantification of LC3 intensity in control (n = 34) and IGF2-treated oocytes (n = 25). A Student’s t-test (two-tailed). *p C) TUNEL assay of control and IGF2-treated oocytes from aged mice. A green fluorescence signal indicates TUNEL-positive oocytes. Apoptotic signals were observed after 16 h of in vitro culture. DNA was counterstained with DAPI. Scale bar = 30 μm. (D) The percentage of apoptosis-positive oocytes in control (n = 61) and IGF2-treated oocytes group (n = 44). A Student’s t-test (two-tailed). *p E) qPCR results showing mRNA levels of Sirt1, Bmp15, Gdf9, and Sod1 in MII-stage oocytes after in vitro maturation with or without IGF2-treatment. *p t-test (two-tailed). Error bars indicate the SEM.

Figure 6. IGF2 reduces the apoptosis and promotes the level of autophagy in aged mouse oocytes. (A) LC3 staining showing the extent of autophagy occurring in control and IGF2-treated oocytes. (B) Quantification of LC3 intensity in control (n = 34) and IGF2-treated oocytes (n = 25). A Student’s t-test (two-tailed). *p < 0.05. Error bars indicate the SEM. (C) TUNEL assay of control and IGF2-treated oocytes from aged mice. A green fluorescence signal indicates TUNEL-positive oocytes. Apoptotic signals were observed after 16 h of in vitro culture. DNA was counterstained with DAPI. Scale bar = 30 μm. (D) The percentage of apoptosis-positive oocytes in control (n = 61) and IGF2-treated oocytes group (n = 44). A Student’s t-test (two-tailed). *p < 0.05. Error bars indicate the SEM. (E) qPCR results showing mRNA levels of Sirt1, Bmp15, Gdf9, and Sod1 in MII-stage oocytes after in vitro maturation with or without IGF2-treatment. *p < 0.05. A Student’s t-test (two-tailed). Error bars indicate the SEM.