Research Paper Volume 13, Issue 2 pp 2118—2134

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

IGF2 administration in culture medium improves the oocytes maturation and early embryonic developmental competence of aged mice. (A) Schematic diagram showing IGF2-treatment of oocytes and early embryos in M16 medium in vitro. (B, C) Quantitative analysis of GVBD (B) and Pb1 extrusion in control oocytes (n = 164) and IGF2-treated oocytes (n = 180) (C). (D) Quantitative analysis of blastocysts in control embryos (n = 218) and IGF2-treated embryos (n = 222). (E) Morphology of in vitro cultured oocytes and embryos examined for development within specific time frames. Arrows indicate the oocytes which failed to extrude a polar body; arrowheads denote embryos which failed to develop into blastocysts. Scale bar, 100 μm. (F) Quantitative analysis of the pregnancy rate in the control and IGF2-treated embryos. 15 blastocysts were transferred into the uterus of each female. n here indicates the numbers of females used as recipients. *p t-test (two-tailed). NS, not significant.

Figure 2. IGF2 administration in culture medium improves the oocytes maturation and early embryonic developmental competence of aged mice. (A) Schematic diagram showing IGF2-treatment of oocytes and early embryos in M16 medium in vitro. (B, C) Quantitative analysis of GVBD (B) and Pb1 extrusion in control oocytes (n = 164) and IGF2-treated oocytes (n = 180) (C). (D) Quantitative analysis of blastocysts in control embryos (n = 218) and IGF2-treated embryos (n = 222). (E) Morphology of in vitro cultured oocytes and embryos examined for development within specific time frames. Arrows indicate the oocytes which failed to extrude a polar body; arrowheads denote embryos which failed to develop into blastocysts. Scale bar, 100 μm. (F) Quantitative analysis of the pregnancy rate in the control and IGF2-treated embryos. 15 blastocysts were transferred into the uterus of each female. n here indicates the numbers of females used as recipients. *p < 0.05. A Student’s t-test (two-tailed). NS, not significant.