FIGURE 2.

NAMPT depletion disrupts meiotic progression and metabolic function in oocytes. (a) Depletion of NAMPT protein was verified by western blot analysis (200 oocytes per lane). (b,c) Quantitative analysis of GVBD and Pb1 extrusion in controls (n = 115) and NAMPT‐KD (n = 110) oocytes. (d) Bright‐filed images of NAMPT‐KD and control oocytes. White arrowheads indicate the oocytes that fail to extrude polar bodies and black asterisks denote oocytes with aberrant asymmetric division. Scale bars: 80 µm. (e) Representative images of meiotic spindle and chromosomes in control and NAMPT‐KD oocytes. Spindle disorganization and chromosome misalignment are indicated by arrowheads. Scale bars: 30 µm. (f) Quantitative analysis of meiotic defects in control (n = 127) and NAMPT‐KD (n = 103) oocytes. (g) NAD⁺ content in control and NAMPT‐KD oocytes (n = 150 for each group). (h) Representative images of CM‐H2DCFDA fluorescence (green) in oocytes from control and NAMPT‐KD oocytes. Scale bars: 50 µm. (i) Quantification of the levels of ROS in oocytes. Each data point represents an oocyte (n = 15 for each group). Data are expressed as the mean ± SD from three independent experiments. A Student's t test (two‐tailed) was used for statistical analysis. ***p < 0.001. GVBD, germinal vesicle breakdown; NAMPT, nicotinamide phosphoribosyl transferase; NAMPT‐KD, NAMPT protein was knocked down; n.s., not significant; ROS, reactive oxygen species