Fig. 5

STE exposure disrupts assembly of the spindle/chromosome apparatus in mouse oocytes. (A) Oocytes were immunostained with anti-α-tubulin-FITC antibody to visualize spindle morphology (green) and counterstained with propidium iodide (PI) to show chromosomal alignment (red). (a) Control oocytes exhibit the characteristic barrel-shaped spindle and well-aligned chromosomes. (b-d) Three examples illustrate the disorganized spindles (arrows) and misaligned chromosomes (arrowheads), which were frequently observed in STE-exposed oocytes (scale bar, 20 μm). (B) The proportion of aberrant spindles and chromosome alignment were quantified in control and STE-exposed oocytes (control group, 10.5 ± 2.20% [number of replicates = 3, number of oocytes = 53, and number of mice = 3; STE group, 36.3 ± 7.43% [number of replicates = 3, number of oocytes = 57, and number of mice = 3]). (C) Expression of acetylated tubulin levels in control and STE-exposed oocytes. Proteins from 200 oocytes were loaded for each sample. (D) Relative-intensity results for AC-Tubulin protein expression in the control and STE-treated oocytes. Data are presented as mean percentage (mean ± SD) from at least three independent experiments (**significantly different at p < 0.01)