Fig 1: TDP-43 interacts with Pol II in mouse two-cell embryos.a Immunostaining of the phosphorylated Ser2 of C-terminal domain of Polr2a subunit (P-Ser2) in normal control and Tdp43oKO L2C (late two-cell embryos, n ≥ 30). The enlarged pictures of one nucleus of 2-cell embryo were shown on the right. Scale bar, 10 μm. b Immunostaining of P-Ser2 and TDP-43 in normal L2C (n ≥ 22) after the simultaneous treatment with 4% PFA and 0.5% Triton X-100 for 25 min, Scale bar, 10 μm. c Western blotting of TDP-43 and Polr2a for Co-immunoprecipitation (Co-IP) products. Mouse embryonic stem cell lysis was Co-precipitated with TDP-43 or Polr2a antibody. The Co-IP products and input were performed for the Western blotting with specific antibodies. Normal rabbit IgG was used as negative control. d Proximity ligation assay (PLA) showing the interaction between TDP-43 and Polr2a in control and Tdp43oKO L2C. L2C (n ≥ 24) were isolated from control and Tdp43oKO females and performed for the PLA with TDP-43 and Polr2a antibody (Materials and Methods). Scale bar, 10 μm. e PLA results of TDP-43 and Polr2a in control and Tdp43oKO (oKO) early 2-cell embryos at different time points (n ≥ 15). pHCG post HCG, h hours. Scale bar, 10 μm. f PLA results of TDP-43 and P-Ser2 in control and Tdp43oKO L2C embryos (n ≥ 25). Scale bar, 10 μm.