Fig. 1

Fig. 1

a Western blot analysis of Apex1 knockdown by morpholino (MO). Upper panel, quantitative analysis of WB. Significant difference is indicated by **p < 0.01. b Increased apurinic/apyrimidinic (AP) sites relative to those in controls after Apex1 knockdown. Data represent the average of five independent experiments ± SD of the mean. Significant difference is indicated by *p < 0.05 and **p < 0.01. c Increased ROS after Apex1 knockdown detected by CM-H2DCFDA. Embryos were microinjected with control MO (panels C1) or 0.2 mM Apex1 MO (panels C2), exposed to CM-H2DCFDA to detect generalized ROS, washed and examined by fluorescence microscopy. Fluorescence was greatly increased in Apex1 knockdown embryos. Photographed at ×4 magnification. d Increased oxidative DNA damage in 24 hpf embryos after Apex1 knockdown. °G levels, detected by immunostaining with TRITC-labeled anti °G mouse monoclonal antibody. Apex1 knockdown embryos (right three embryos) and control embryos (left two embryos) were examined by fluorescence microscopy. These experiments were repeated three times with similar results. e Detection of superoxide anion using MitoSOX red (panels e1 and e2) and nitric oxide using DAF-FM acetate (panels e3 and e4). Embryos were microinjected with vehicle (panels e1 and e3) or Apex1 MO (panels e2 and e4), examined at 4 hpf by confocal microscopy and photographed at ×40 magnification. Note perinuclear mitochondria containing superoxide in Apex1 knockdown embryos (e2) and the appearance of nitric oxide in the yolk syncytial layer in occasional Apex1 knockdown embryos (e4)