Effects of TBBPA exposure on bovine oocyte maturation: (A) Effects of TBBPA exposure on cumulus-cell expansion and polar-body extrusion in oocytes. COCs: scale bar = 200 μm. Metaphase II (MII) oocytes: scale bar = 100 μm. Enlarge: scale bar = 10 μm. (B) Ratio of GVBD in each group. Control, n = 144; TBBPA, n = 152. (B) Polar-body extrusion rate in each group. Control, n = 179; 20 μm TBBPA, n = 196; 40 μm TBBPA, n = 173; 80 μm TBBPA, n = 204. (C) The percentage of first polar-body extrusion was quantified in controls and groups with different concentrations of TBBPA. (D) Cumulus expansion index of each group. Control, n = 152; 20 μm TBBPA, n = 151; 40 μm TBBPA, n = 162; 80 μm TBBPA, n = 201. (E) mRNA expression levels of TNFAIP6 and PTX3. In total, 50 oocytes per group were used for RNA extraction. (F) Representative images of TUNEL staining of cumulus cells. Scale bar = 200 μm. (G) Apoptosis rate in each group. Ex/Em, 529/590; Ex/Em, 371/464 nm. (H) Ratio of BAX/BCL-2 in each group. * p < 0.05, ** p < 0.01, and *** p < 0.001, and ns p > 0.05.