Fig. 1

Effects of STE on maturational competence of mouse oocytes. (A) Representative images of oocytes from control and STE-treated groups. Red arrowheads denote oocytes with apparent symmetrical division and blue arrowheads indicate oocytes that fail to extrude polar bodies (scale bar, 80 μm). (B) The rate of polar body extrusion was significantly lower after STE exposure than in the control group. And the proportion of PB1 was (82.7 ± 3.68% [number of replicates = 3, number of oocytes = 145, and number of mice = 6], 53.0 ± 6.16% [number of replicates = 3, number of oocytes = 132, and number of mice = 6], 44.2 ± 5.14% [number of replicates = 3, number of oocytes = 157, and number of mice = 6], 37.5 ± 4.08% [number of replicates = 3, number of oocytes = 128, and number of mice = 6], 35.0 ± 4.08% [number of replicates = 3, number of oocytes = 116, and number of mice = 6], p < 0.01) in control, 25 µM, 50 µM, 100 µM and 200 µM STE groups, respectively. (C) The percentage of oocytes with large polar bodies after STE-treated. And the proportion of large polar body was (9.6 ± 1.72% [number of replicates = 3, number of oocytes = 145, and number of mice = 6], 18.3 ± 2.35% [number of replicates = 3, number of oocytes = 132, and number of mice = 6], 20.9 ± 1.31% [number of replicates = 3, number of oocytes = 157, and number of mice = 6], 25.6 ± 2.33% [number of replicates = 3, number of oocytes = 128, and number of mice = 6], 18.1 ± 1.32% [number of replicates = 3, number of oocytes = 116, and number of mice = 6], p < 0.01) in control, 25 µM, 50 µM, 100 µM and 200 µM STE groups, respectively. The Figure depicts the mean percentage ± SD of the results obtained from three independent experiments. The bars labeled with completely different letters indicate significant difference at p < 0.01