Simulated Microgravity Compromises Mouse Oocyte Maturation by Disrupting Meiotic Spindle Organization and Inducing Cytoplasmic Blebbing
Figure 2
Simulated microgravity disrupts microtubules aggregation in mouse oocytes.
A. Spindle morphology of mouse oocytes during meiosis cultured under 1 g gravity (a–c) and simulated microgravity (d–f). a) A mouse oocyte cultured at 6 hours. The barrel-shaped MI spindle is seen with microtubules and chromosomes, arranged on the equatorial plate. b) At 8 hours, chromosomes were separating. c) At 16 hours, the mouse oocyte extruded the first polar body and formed the second spindle. d) At 16 hours, the mouse oocyte showed chromosomes attached with few disordered microtubules. e) At 16 hours, chromosomes without microtubules attachment migrated. f) At 16 hours, the mouse oocyte extruded the first polar body and formed the second spindle. Blue = chromosomes, green = microtubules; Scale bar = 10 µm. B. Percent of microtubules subtypes. Oocytes were cultured in 1 g gravity (control, n = 98) and simulated microgravity (smg, n = 136). After 16 hours cultured, the percentage of different phenotypes were analyzed. Little unordered MTs means that there were little unordered microtubules attached to the chromosomes. Unseen MTs means that there were no obvious microtubules attached to chromosomes. This experiment was repeated 3 times. Different letters denote statistical differences between groups. a vs b, P<0.01; c vs d, P<0.05.